Abstracts: 39th Annual Meeting of the American College of Veterinary Ophthalmologists, Boston, MA, USA, October 15–18, 2008


ABSTRACT NO.: 1

Assessment of mucin content in bottlenose dolphin tears

R. Kelleher Davis and D. A. Sullivan
Schepens Eye Research Institute, Harvard Medical School, Boston, MA, USA

Purpose:  In terrestrial mammals, the tear film plays an essential role in maintaining the health of the ocular surface, protecting against toxic challenges in the external environment, thereby preserving visual acuity. This protective function is critically dependent on the integrity of the tear film structure, which is comprised of three layers: an underlying glycoprotein (mucin) foundation, a protein-rich aqueous component, and an overlying lipid layer. In a previous study, we determined that the tears of marine mammals do contain proteins, but that the tear film, examined using interferometry, appears to lack the lipid layer found in terrestrial mammals. This finding is quite significant in that it suggests that in sea mammals, an alternative component, in lieu of lipid, promotes the stability of the tear film. This led us to hypothesize that, in the absence of a lipid layer, a mucin foundation, similar to that found in terrestrial mammals, is critical to the integrity of the tear film of marine mammals. This study was carried out to determine whether dolphin tears contain mucins.

Methods:  Tear samples from Atlantic bottlenose dolphins (Tursiops truncatus) and humans were analyzed for lectin binding to high molecular weight proteins. Tears from dolphins were collected via capillary suction. Tears from human subjects were collected using Wek-cel sponges. Samples were treated with or without sialidase, which removes glycosylated moieties, and then subjected to electrophoresis on sodium dodecyl sulfate–agarose gels to separate out large proteins. Protein was then transferred by Western blotting onto nitrocellulose membranes and analyzed for the binding of the lectins, peanut agglutinin (PNA) and Sambucus nigra (SNA).

Results:  If mucins were present in the tears, it would be expected that PNA would bind to high molecular weight proteins from tear samples treated with sialidase, and that SNA would bind to tear samples not treated with sialidase, for PNA binds to the core of the mucin while SNA binds to glycosylated moieties. In both human and dolphin tears, those treated with sialidase did bind the biotinylated lectin, PNA, but not the SNA. Whereas, untreated tears bound the biotinylated SNA, but not PNA. This differential result confirms the presence of mucins in dolphin tears.

Conclusions:  Our finding that large glycoproteins are present in the tears of bottlenose dolphins supports the hypothesis that mucins play a critical role in the protection of the surface of the eyes of marine mammals. Thanks to S. H. Ridgway for tear samples and P. Arguesso and S. Spurr-Michaud for technical advice. Supported by Arey's Pond Boat Yard Inc. and NIH grant EY05612.

ABSTRACT NO.: 2

Determination of the risk factors involved in lens diseases in captive pinnipeds: final analysis

C. M. H. Colitz* , †, W. J. A. Saville†, M. S. Renner‡ ,, †††, E. J. Chittick§, P. Clough¶, S. Collins**, L. Dalton††, C. Dold‡‡, S. Dugan§§, F. Knightly¶¶, J. McBain**, J. Mejia‡ , ***, P. Ollen-Hughes†††, B. Osborne†††, S. Osborn††, T. Reidarson**, M. M. Rodriguez‡, T. Schmitt** and M. Walsh‡‡‡
*Animal Eye Specialty Clinic, West Palm Beach, FL, USA; †College of Veterinary Medicine, Ohio State University, Columbus, OH, USA; ‡Miami Seaquarium, Miami, FL, USA; §Disney's Animal Kingdom, Orlando, FL, USA; ¶Dolphin Research Center, Grassy Key, FL, USA; **Seaworld California, San Diego, CA, USA; ††Seaworld Texas, San Antonio, TX, USA; ‡‡Seaworld Florida, Orlando, FL, USA; §§Eye Specialists for Animals, Denver, CO, USA; ¶¶Denver Zoo, Denver, CO, USA; ***Mississippi State University College of Veterinary Medicine, Mississippi State, MS, USA; †††Theater of the Sea, Islamorada, FL, USA; ‡‡‡Atlanta Aquarium, Atlanta, GA, USA

Introduction:  Pinnipeds have a high incidence of lens diseases including lens luxation and cataract. A questionnaire was created in order to evaluate the risk factors associated with lens diseases in pinnipeds.

Materials and Methods:  Descriptive and univariate analysis were performed on data collected. One hundred and eleven pinnipeds from nine facilities were included in the questionnaire.

Results:  This study has demonstrated that there are risk factors for pinnipeds to develop cataracts or lens luxations including: age, history of fights, history of ocular disease, and availability of shade.

Conclusions:  Lens diseases including cataracts and lens luxations occur in both captive and wild pinnipeds. Cataracts and lens luxation have genetic, environmental and aging causes. In all species evaluated to date, sunlight (ultraviolet radiation) is a major cause of cataracts. Since cataracts were primarily seen in animals over 15 years of age and they are exposed to chronic sunlight over the course of their lives, implementation of sun protective shade (tarp of other ultraviolet protective materials) should help to diminish the development of cataracts in these animals. Supported by the Columbus Zoo and Aquarium and the Ohio State University's Matching Research funds.

ABSTRACT NO.: 3

Use of rebound tonometry as a diagnostic tool to diagnose glaucoma in the captive California Sea Lion

J. C. Mejia-Fava * , S. W. Jack†, C. Colitz‡, C. C. Clemons-Chevis § , M. Rodriguez* and M. Renner*
*Miami Seaquarium, Miami, FL, USA; †College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA; ‡Animal Eye Specialty Clinic, West Palm Beach, FL, USA; §Institute for Marine Mammal Studies, Gulfport, MS, USA

Purpose:  One of the most common medical problems seen in the California Sea Lion (Zalophus californianus) is ocular disease. Glaucoma is a disease that has not been evaluated extensively in the sea lion. Observing clinical signs and measuring intraocular pressures (IOP) is critical for early diagnosis. The objective of this project is to measure IOP in clinically normal California Sea Lions without ocular pathology to establish a normal range.

Methods:  The Tono-Vet® (Tiolat, Helsinki, Finland) was selected to be used in the study. Tono-Vet uses a new noninvasive, rebound method to estimate IOP. An electrical magnetic tonometer probe comes into contact with and rebounds from the corneal surface to estimate an IOP. In order to record an accurate IOP, six measurements were taken and averaged resulting with the mean value. A complete ophthalmic examination has been or will be performed on all sea lions by a veterinary ophthalmologist.

Results:  Currently, there are 19 sea lions in the study with no ocular pathology. Preliminary data on these animals suggests thus far a range of 21 to 42 mmHg.

Conclusion:  The future objective of this study is to establish a normal baseline range for IOP values in captive sea lions with no ocular pathology. This range will provide a comparative measurement when evaluating a diseased eye. By measuring the IOP regularly in young adult sea lions, veterinarians will be able to determine when IOP's begin to change so that medical management can be started prior to loss of vision.

ABSTRACT NO.: 4

Gene expression of membrane-associated mucins in the canine ocular surface

Y. Umeda*†, S. Nakamura‡, K. Fujiki†, H. Toshida†, A. Saito* and A. Murakami†
*Triangle Animal Eye Clinic, Tokyo, Japan; †Department of Ophthalmology and ‡Division of Biomedical Imaging Research, Biomedical Research Center, School of Medicine, Juntendo University, Tokyo, Japan

Purpose:  Mucin is one of the components of tear film and very important to maintain ocular surface to keep intact. Although goblet cell was thought to be the only one cell type which produced and secreted mucin at first, it was recently revealed that corneal and conjunctival epithelial cell also expressed the mucins. There are at least three membrane-associated mucins: MUCs 1 and 16 have been expressed in human corneal epithelial cells, and MUCs 1, 4, and 16 in conjunctival epithelial cells. The purpose of this study is to determine what kind of mucin genes have been expressed in canine ocular surface.

Methods:  Corneal, conjunctival, and nictitating membrane tissues were dissected from three young Beagles under general anesthesia. They were frozen immediately in the liquid nitrogen and stored at −80 °C. Total RNA was isolated from tissues using TRIzol reagent (Invitrogen, Rockville, MD, USA) following the protocol. Reverse transcription–polymerase chain reaction (RT-PCR) was performed to identify the mucin genes in the canine ocular tissues.

Results:  RT-PCR analysis detected that MUC1 and 16 have been expressed in the canine corneal tissues, and MUC1, 4, and 16 in the conjunctival and nictitating membrane tissues.

Conclusions:  We recognized that membrane-associated mucins: MUCs 1, 4, and 16 have been expressed in canine ocular surface as same as in the human tissues.

ABSTRACT NO.: 5

Canine corneal stromal cell isolation

N. S. Trumble*, D. E. Brooks* and M. Clare-Salzler†
*College of Veterinary Medicine and †College of Medicine, University of Florida, Gainesville, FL, USA

Purpose:  This study aims to develop and compare methods of isolating viable canine corneal stromal cells.

Methods:  Canine corneas were harvested from dogs euthanized for unrelated reasons. Epithelia were removed after incubation in EDTA. Stromas were processed via tissue culture or tissue digestion. Tissue culture was performed by stromal incubation in RPMI-based media for 10–14 days at concentrations of 1/4, 1/2, or 1 stroma per 800 µL. Tissue digestion was performed by stromal incubation in collagenase D solution for 24 h. All incubations were performed at 37 °C and 5% CO2. Cells adherent to the incubation plates were released via trypsinization. All cells were routinely washed and collected. Cellular yields were determined by microcytometry, and were compared using a Student's t-test.

Results:  Cumulative cellular yield (cells/cornea, mean ± SD) for the tissue culture method ranged from 14.8 K ± 1.6 K to 41.0 K ± 2.9 K at 14 days. The maximal yield was achieved with a tissue concentration of 1 stroma per 800 µL. This maximum was not significantly greater than the yield using the 24 h tissue digestion method, which was 6.9 K ± 4.4 K cells/cornea (P > 0.98).

Conclusions:  Corneal stromal cells can be harvested via tissue culture over 14 days to yield up to 41.0 K ± 2.9 K cells/cornea. Corneal tissue digestion is a less time and labor intensive method, providing a yield of 6.9 K ± 4.4 K cell/cornea.

ABSTRACT NO.: 6

Localization of integrin subunits α3, α6, β1, and β4 in the normal canine cornea

D. M. Dorbandt*, K. J. Waite*, T. W. Morgan† and R. T. Carter*
Departments of *Veterinary Clinical Sciences and †Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA

Purpose:  This study aims to evaluate for the presence and to determine the pattern of distribution of integrin subunits α3, α6, β1, and β4 in normal canine cornea.

Methods:  Ten whole globes were collected from clinically normal mixed-breed dogs estimated to be between 1 and 5 years of age. Eyes were fixed in 10% neutral buffered formalin and embedded in paraffin. A EDTA section of each eye was evaluated prior to inclusion in the study. Two eyes were withdrawn from the study due to abnormal histopathology, and one eye was withdrawn due to complications during the embedding process. Standard immunohistochemical techniques were employed using commercially available antibodies to integrin subunits α3, α6, β1, and β4. Sections were incubated without either primary or secondary antibody as a negative control. Cytoplasmic staining was used to identify positive cells.

Results:  All evaluated corneas were positive for integrin subunits α3, α6, β1, and β4. Subunit α3 stained evenly diffuse throughout all epithelial layers while subunits α6, β1, and β4 demonstrated concentrated staining of basal and wing cells. Various nonstaining cells were observed sporadically throughout the basal cell layer. Western blot analysis of normal corneal homogenates confirmed the presence of integrin subunits α3, α6, β1, and β4.

Conclusions:  The normal canine epithelium contains integrin subunits α3, α6, β1, and β4 with a distribution similar to that reported in other species. The nonstaining cells are believed to be differentiating corneal epithelial cells. Supported by the Merck-Merial Summer Scholars Program.

ABSTRACT NO.: 7

Does retinal disease lead to refractive error?

B. C. O’Connor*, G. S. Ying† and A. M. Komáromy*
Departments of *Clinical Studies and †Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA

Purpose:  Visual deprivation can affect eye growth and lead to refractive error. The goal of this study was to determine if impaired photoreceptor function in dogs with inherited retinopathies affects the ocular development and results in refractive error.

Methods:  Streak retinoscopy was performed in adult, mongrel dogs. These animals included normal controls (n = 11), as well as dogs affected by inherited retinopathies with onset before (early) or after (late) retinal development was completed at 6 weeks of age.

Refractive errors of each group were compared to the normal controls by uni- and multivariate analyses, adjusted for age and gender. Correlations in refractive error from paired eyes of the same dog were adjusted by generalized estimating equation.

DiseasenOnsetRetinal degeneration
Rod-cone dysplasia (RCD)5EarlyYes
RPE65-Leber congenital amaurosis (RPE65-LCA)6EarlyNo
Achromatopsia (ACHM)9EarlyNo
Cone-rod dystrophy (CRD)9LateYes
X-linked progressive retinal atrophy 1 (XLPRA1)3LateYes
Progressive rod-cone degeneration (PRCD)3LateYes

Results:  Control dogs were close to emmetropic with a mean refractive error (± standard error) of −0.20 ± 0.25 Diopters (D). The largest degree of myopia was found in RCD dogs with early rod photoreceptor disease (−2.98 ± 0.53 D; P < 0.0001). In contrast, dogs with the congenital retinal pigment epithelium (RPE) disease RPE65-LCA did not show significant refractive errors (+0.35 ± 0.30 D). Loss of cone function in the ACHM dogs after 6–8 weeks of age also did not lead to significant refractive error (+0.02 ± 0.27 D). Similarly, the late-onset diseases CRD (−0.71 ± 0.35 D) and PRCD (+0.24 ± 0.34 D) did not result in significant refractive errors. Mild, but significant myopia (−0.80 ± 0.14) was detected in the XLPRA1 group (P < 0.05).

Conclusions:  Primary rod photoreceptor disease occurring during ocular development leads to significant myopia. Primary cone and RPE diseases as well as most late-onset retinal degenerations do not seem to result in refractive error. Supported by NIH and FFB.

ABSTRACT NO.: 8

Clinical features of distichiasis/ectopic cilia in dogs

T. H. Kim, S. A. Park, M. B. Jeong, W. T. Kim, S. E. Kim, Y. W. Park, J. S. Ahn and K. M. Seo
Department of Veterinary Surgery and Ophthalmology, College of Veterinary Medicine and BK21 Program for Veterinary Science, Seoul National University, Seoul, South Korea

Purpose:  The purpose of this study was to investigate the clinical features of distichiasis/ectopic cilia in dogs.

Methods:  Medical records were reviewed for dogs with only distichiasis (87 cases), and distichiasis + ectopic cilia (7 cases) presented to the Veterinary Medical Teaching Hospital in Seoul National University. Breed of the patient, laterality and secondary corneal lesions of the affected eyes, and location of the abnormal cilia were analyzed. The eyelids with abnormal cilia were divided into six parts by the location: dorsolateral, dorsomiddle, dorsomedial, ventromedial, ventromiddle, and ventrolateral part.

Results:  Common breeds with the abnormal cilia were Shih-Tzu (50.6%), Cocker Spaniel (25.0%), and Pekingese (6.9%) in order. Most of the distichiasis/ectopic cilia were bilateral (70.2%). More than half of the eyes with the abnormal cilia (51.2%) included corneal lesions: neovascularization (17.5%), pigmentation (13.8%), opacity (11.9%), ulceration (9.4%), and edema (9.4%). The incidence of secondary corneal lesion in each breed was not proportionate to that of the abnormal cilia: Pekingese (90.9%), Shih-Tzu (70.4%), and Poodle (42.9%). In addition, only 5.0% of Cocker Spaniel with distichiasis suffered from the corneal lesions. These corneal lesions by ectopic cilia had higher incidence (66.7%) and severity than those in distichiasis. The most common location of distichiasis (31.2%)/ectopic cilia (76.9%) was the dorsomiddle part in all breeds.

Conclusions:  For the breed such as Shih-Tzu and Pekingnese with the distichiasis and ectopic cilia, prophylactic surgical removal could be considered in order to protect cornea from the abnormal cilia.

ABSTRACT NO.: 9

Partial ligation of the transposed parotid duct at the level of the parotid gland for excessive salivary secretions in the Yorkshire Terrier breed: three cases

H. K. Schilke and J. S. Sapienza
Long Island Veterinary Specialists, Plainview, NY, USA

Purpose:  This study aims to determine the outcome and effect of a partial ligation of the transposed parotid duct at the level of the parotid gland in three Yorkshire Terriers with excessive saliva production and ocular irritation.

Methods:  Three Yorkshire terriers (two spayed females and one castrated male) with an average age of 3 years (range: 1–5 years) were previously diagnosed with absolute keratoconjunctivitis sicca. After a parotid duct transposition (PDT) surgery, the dogs experienced excessive saliva production and abundant salivary precipitates, which resulted in epiphora, blepharospasm, and keratitis. In an effort to decrease saliva production, a partial ligation of the transposed duct at the level of the parotid gland was performed. Two or three accessory branches to the primary parotid duct were ligated at the level of the salivary gland.

Results:  Partial ligation of the parotid duct proved to be an effective technique in moderating the saliva production in these Yorkshire Terriers with excessive salivary secretions after parotid duct transposition. One patient had a partial ligation performed at the time of the parotid duct transposition, which did not adequately control the excessive saliva production postoperatively. A second partial ligation was necessary in this patient. After partial ligation, all animals in this study demonstrated improved ocular comfort, decreased salivary precipitates, and adequate Schirmer tear test results without marked epiphora.

Conclusions:  This report demonstrates that partial ligation of accessory branches of the parotid duct at the level of the parotid gland is an effective technique to control excessive saliva production and to reduce salivary precipitates formation in Yorkshire terriers after a primary PDT.

ABSTRACT NO.: 10

Corneal sequestrum in a dog

S. Pizzirani*, C. G. Pirie* and N. M. Parry†
Departments of *Clinical Sciences and †Biomedical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA, USA

Purpose:  This study describes a case of corneal sequestrum in a dog.

Methods:  A 14-year-old, castrated male Cairn Terrier, with a remote history of KCS in the left eye (OS) was presented for severe blepharospasm and a black plaque involving the OS of 3 weeks’ duration. On clinical examination menace was present in the right eye (OD) and absent in the OS. Pupillary light and dazzle reflexes were normal in both eyes. The left cornea showed an 8 × 5-mm black plaque involving the central cornea, surrounded by fibrovascular tissue and corneal melting. The plaque was surgically removed with a superficial keratectomy and a hood conjunctival graft was applied.

Results:  Streptococcus beta-hemolyticus was isolated by the cultured specimen. Histopathology (hematoxylin–eosin) showed outer stromal necrosis and surrounding pyogranulomatous infiltrate and fibrovascular reaction. Gram stain was negative. Von Kossa and PAS staining were unremarkable. PCR for canine herpesvirus was negative and transmission electron microscopy showed collagen disruption with interspersed macrophages. No viral particles or evidence of other infectious agents were seen. The graft was trimmed 2 weeks after surgery. At rechecks, STT was consistently low (5 mm/60 sec) despite tacrolimus treatment. Four months after surgery pigmentary keratitis was present surrounding the graft. The patient was lost then to follow-up.

Conclusions:  Chronic KCS and the old age of the patient may have been contributing factors for development of an atypical corneal sequestrum in this case, although von Kossa staining was unable to detect any calcific degeneration of the cornea.

ABSTRACT NO.: 11

Comparative quantitative analysis of protein values of aqueous humor and total blood protein in healthy dogs

M. S. A. Falcão*, P. D. Galera*, R. Vitelli*, R. R. Ramos*, T. C. Ferreira† and E. G. Campos†
*College of Veterinary Medicine and †Celular Biology Laboratory, University of Brasilia, Brasilia, Brazil

Purpose:  It has been shown that the increase of protein in the aqueous humor is an indicative for an accurate diagnostic of uveitis. The aim of this study was compare two methods of protein detection (Bradford and Sensiprot® test) to quantify protein values in aqueous humor and correlate it with the values of the total blood protein.

Methods:  Twenty-two, health mixed-breed dogs (8 females and 14 males), aged 2–8 were submitted to a general anesthesia for anterior chamber paracentesis; 0.3 mL of aqueous humor was drawn from right eye (RE) and left eye (LE). The sample was frozen (T −4 °C) and processed. The amount of protein aqueous humor was measured by the Bradford method and the direct colorimetric pirogalol red dye method (Sensiprot®, Labtest Diagnóstica SA, Lagoa Santa, Minas Gerais, Brazil). Blood was drawn for total protein blood quantification. One-way analysis of variance was followed by Tukey's multiple comparison test, which showed P-values less than 0.05 (P < 0.05) significance and presented as mean ± SEM values.

Results:  Bradford method detected 33.88 mg/dL for the RE and 36.82 mg/dL LE. Our data obtained by the method of Bradford were similar to described in the literature and the values obtained by the Bradford method represent 0.5% of plasma values. Sensiprot® method detected 9.04 mg/dL RE and 7.56 mg/dL LE.

Conclusions:  Bradford test has higher sensitivity for mesurement of aqueous humor proteins and presented a positive correlation between increase of protein in plasma and aqueous humor. Supported by FINATEC; FAPDF.

ABSTRACT NO.: 12

Seasonal intraocular pressure variations in normal sapsaree dogs

J. M. Chae*†, T. H. Kim*, M. B. Jeong*, N. Y. Yi*‡, S. A. Park*, W. T. Kim* and K. M. Seo*
*Department of Veterinary Ophthalmology and Surgery, College of Veterinary Medicine and BK21 Program for Veterinary Science, Seoul National University, Seoul, South Korea; †Department of Ophthalmology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA; ‡Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA

Purpose:  The purpose of this study was to investigate seasonal intraocular pressure (IOP) variations in Sapsaree dogs.

Methods:  Both eyes of 482 clinically normal Sapsaree dogs (210 male, 272 female) were evaluated. Tonopen® XL was used to measure IOP between 10:00 am and 2:00 pm. Four valid IOP readings with ≤ 5% variance were obtained from each eye. The values were divided into four seasonal groups: spring (March to May), summer (June to August), autumn (September to November), and winter (December to February). The IOP results were compared by one-way analysis of vaiance and analysis of covariance, followed by a Bonferroni post-hoc test. The level of significance in all comparisons was set at P < 0.05.

Results:  The mean IOP value of Sapsaree dogs was 19.4 ± 3.6 mmHg (range, 8–28 mmHg). The IOP value in winter (20.4 ± 3.5 mmHg) was significantly higher than in other seasons, and the IOP value in summer (17.2 ± 3.8 mmHg) was also significantly lower than in other seasons. However, there were no differences in the IOP values between spring (19.3 ± 3.3 mmHg) and autumn (19.1 ± 3.8 mmHg). No significant difference in IOP was related to sex (P = 0.345) or age (P = 0.120).

Conclusion:  We found that the seasons may affect the IOP values in Sapsaree dogs and we hypothesize that this variation may be related to seasonal hormone and blood pressure variation. Supported by Korea Research Foundation Grant, KRD-2006-E00153.

ABSTRACT NO.: 13

The relationship of the iridocorneal angle, as measured using ultrasound biomicroscopy, with postoperative increases in intraocular pressure postphacoemulsification in dogs

W. R. Crumley, J. R. Gionfriddo and S. V. Radecki
Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA

Purpose:  This study aims to investigate the relationship of the iridocorneal angle as it appears on ultrasound biomicroscopy (UBM) to increases in intraocular pressure postphacoemulsification in the canine eye.

Methods:  Forty-seven eyes of 28 dogs of various age, sex, and breed were studied. The ciliary process and limbus were used as a reference points to measure the angle opening distance (AOD), which was set by multiplying 0.45 by the distance between the ciliary process and limbus (when measured from the ciliary process). Pressure measurements were taken at 5 set points: Prior to, immediately post-, 1 day post-, 1 week post-, and 1 month post-phacoemulsification.

Results:  A weak relationship between the AOD and the intraocular pressure one day postphacoemulsification (intercept: 2.83, slope: −1.24, P-value: 0.0155) was observed. No relationship immediately postoperative (intercept: 3.45, slope: −1.34, P-value: 0.0651), 1 week postphacoemulsification (intercept: 2.31, slope: −0.01, P-value: 0.9829), 1 month post-phacoemulsification (intercept: 1.85, slope: −0.49, P-value: 0.1533) was observed. The preoperative measurements made with UBM were: Distance from limbus to ciliary process (DLCP): (Minimum: 1.152, Maximum: 2.992, Mean: 1.91, SD: 0.468); AOD (Minimum: 0.104, Maximum: 0.764, Mean: 0.40, SD: 0.172).

Conclusions:  The relationship between AOD as measured by UBM preoperatively is weakly associated with intraocular pressure pressure elevations at day 1 postphacoemulsification. Further study is required prospectively to establish the importance of this relationship. Initial measurements of the canine iridocorneal angle were created, suggesting a method to be used in the future to establish true canine normal measurements.

ABSTRACT NO.: 14

Standardization of the Schirmer tear test values in Persian and cross-bred cats

P. D. Galera, L. S. Wanderley, A. C. V. R. Almeida, M. S. Falcão and V. S. P. Gonçalves
Faculty of Agriculture and Veterinary Medicine, University of Brasilia, Brasilia, Brazil

Purpose:  This study aims to compare the Schirmer tear test (STT) values between groups of Persian and cross-bred cats.

Methods:  Overall, 104 clinically healthy cats without ophthalmic problem were tested, of which 59 were females and 45 males; 34 were assigned to the Persian group, 62 were cross-bred and 8 cats were of other breeds, with ages ranging from 4 months to 12 years. The STT-1 was applied to each animal, on the right (RE) and left (LE) eyes, totaling 208 eyes. These data were stored and analyzed using Microsoft Excel 2003®.

Results:  The mean value of the 104 observations was 16.73 and 19.16 mm/min for the RE and LE, respectively. The standard deviation was high: 8.01 for the RE and 7.67 for the LE, indicating wide dispersion for the individual values around the mean. The 95% confidence interval of the mean value ranged from 13.97 to 18.47 mm/min, for the RE, and between 15.49 and 19.77 for the LE. There was a statistically significant (P < 0.05) difference of the STT results between breeds, as evaluated by the t-test for paired samples.

Conclusions:  The STT values were higher in Persian cats compared cross-bred cats. For both breeds, there was wide dispersion of values around the mean, rendering it difficult to establish a clear standard that would provide a guide to clinicians trying to diagnose ophthalmic problems. Supported by FINATEC; FAPDF.

ABSTRACT NO.: 15

Feline conjunctival melanoma: histopathological characteristics and clinical outcomes

C. S. Schobert and R. R. Dubielzig
School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA

Purpose:  Conjunctival melanoma is a rare tumor in cats. We report on the morphology and clinical features of 19 cases. Also reported are preliminary results on the behavior and clinical outcome of this neoplasm.

Methods:  Nineteen cases of feline conjunctival melanoma were selected from the COPLOW collection, which includes almost 3000 neoplastic specimens in cats. The authors examined hematoxylin–section sections from each case and tabulated parameters such as location of the tumor, pigmentation, cell shape, and presence of giant cells. Mitotic index will also be determined for each case once the pigmented samples are bleached. Additionally, surveys were sent to referring ophthalmologists to obtain further information about each case such as metastasis and survival time after diagnosis. To date, we have received data for 5 of the cases with additional information expected as clinicians respond to the surveys and follow-up phone calls.

Results:  The mean age of the cats was 12 years, with a range from 2 to 17 years. No breed or sex predilection was observed. A gender predilection was observed, with 13 of the cases neutered males, 4 spayed females, and 1 each of intact male and female. Ten of the 19 cases were located on the bulbar conjunctiva, 3 were on third eyelid only, 3 on palpebral conjunctiva, 1 on both third eyelid and palpebral conjunctiva, and in 2 of the cases, it was impossible to determine precise location. Thirteen tumors were pigmented (10 heavily and 3 lightly) while 6 were amelanotic. Sixteen of the cases consisted of round cell only while 3 cases were mixed populations of round and spindle cell. Fourteen of the cases contained giant cells. Of the 5 cases with data regarding outcomes, 4 showed metastatic disease and were dead, 3 by euthanasia. The cat without metastatic disease is still alive 2 years postdiagnosis. In the group of 5, survival time ranged from 2 to 24 months, with a mean of 12 months.

Conclusions:  Feline conjunctival melanoma is most frequently found on the bulbar conjunctiva, the majority of the tumors are round cell populations and pigmented, and giant cells are seen in the majority of cases. Our follow-up results suggest that a cat with conjunctival melanoma has a high metastatic rate and a higher mortality rate than conjunctival melanoma in dogs.

ABSTRACT NO.: 16

Bilateral feline acute bullous keratopathy and immunosupressive drugs

C. Evans, D. A. Wilkie, A. Lara Garcia, S. G. Stone, A. J. Gemensky Metzler, C. L. Robinson and C. R. Basham
Department of Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus, OH, USA

Purpose:  The purpose of this study is to describe two cases of bilateral feline acute bullous keratopathy (ABK) occurring after high immunosuppressive doses of systemic cyclosporine and prednisolone.

Methods:  Two cases of feline acute bullous keratopathy were reviewed. Their previous medical history, ophthalmic exam findings and ABK treatment were compared.

Results:  The similarities of the cases include the use of oral cyclosporine and prednisolone therapy for immunosupression for immune-mediated hemolytic anemia. Oral cyclosporine was dosed at 25 mg per cat twice daily and oral prednisolone was dosed at 3.5–4 mg/kg/day. In one cat, bilateral bullous keratopathy lesions developed within 18 h of each other. Due to aqueous humor leakage, bilateral conjunctival hood grafts were performed. Blood levels of cyclosporine were four to five times the normal therapeutic levels in this patient. The second cat developed rapidly progressive corneal bullae bilaterally within 64 days of initial lesions. One eye was successfully treated medically with topical oxytetracycline/polymixin B ointment whereas the contralateral eye required a conjunctival hood graft.

Conclusion:  Cats treated with high immunosuppressive doses of systemic cyclosporine and prednisolone should be monitored for the development of ABK. Cats presenting with ABK should be monitored for the rapidly progressive corneal bullae and aqueous humor leakage developing within 24–48 h. Keratectomy, conjunctival grafting, and postoperative topical oxytetracycline have been successful in halting progression of ABK. Corticosteroids and doxycycline decrease metabolism of cyclosporine, possibly to levels that were toxic to the corneas in these cases. However, an immune-mediated or herpesvirus component to the keratopathy cannot be ruled out.

ABSTRACT NO.: 17

Bacterial contamination rate of ophthalmic solution

N. Takiyama, M. Sakai, H. Koie and M. Uechi
Laboratory of Veterinary Internal Medicine, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, Tokyo, Japan

Purpose:  This study aims to investigate the bacterial contamination rate of topical ophthalmic solution in educated group and non-educated group.

Methods:  Thirty-two volunteers were divided into two groups. Sixteen were educated how to use eye drops to avoid contamination (group E), and the others were not educated (group N). 0.1% sodium hyaluronate ophthalmic solutions contain benzalkonium chloride 0.01% (Hyalein 0.1, Santen, Osaka, Japan) was used for this study. Six clinically healthy Beagle dogs were received ophthalmic solution unilaterally for 7 days. Aerobic and anaerobic cultures of the solutions were obtained at 0, 4, and 7 days.

Results:  All samples at 0 day had no growth of bacteria. No sample of group E and eight samples of group N had bacteria cultured at 4 days. Two samples of group E and 12 samples grew organisms at 7 days. Proteus mirabilis and Psudomonas aeruginosa were most common bacteria cultured from these samples.

Conclusions:  The results of this study indicate that ophthalmic solutions become contaminated with bacteria and that contamination is related to education and duration of use. Commercial interests: None.

ABSTRACT NO.: 18

Histologic evaluation of commercially available tissue supports for small ocular samples

E. M. Whitley*, E. Landreth*, U. Wohlfert* and R. D. Whitley†
Departments of *Pathobiology and †Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL, USA

Purpose:  Orientation and gentle handling of small biopsy samples during the histologic embedding process is problematic because of tissue curling and loss of anatomic reference. Small clinical biopsies of corneal and conjunctival tissue are routinely processed at Auburn University using ethanol-fixed cucumber supports. This study compared ethanol-, sucrose-, and acetic acid-fixed cucumber to identify an optimal method to process small tissue samples while maintaining cellular morphology and proper tissue orientation and reducing artifacts.

Methods:  Corneal and conjunctival samples were collected from necropsy patients and placed on cucumber sections that had been fixed in 95% ethanol or on sections of commercially available, sucrose- or acetic acid-fixed cucumber (‘bread and butter’ and ‘dill’ pickles, respectively). The biopsy-cucumber unit was placed in a plastic cassette, fixed in formalin, and processed routinely for histopathology.

Results:  All three mounting systems produced excellent cytomorphology. Tissue samples adhered well to each of the three types of mount. Sectioning of ethanol-fixed and acetic acid-fixed cucumber was optimal, compared with sucrose-fixed cucumber, which had a very soft consistency.

Conclusions:  Ethanol- and acetic acid-fixed cucumber supports provide a solid support for proper orientation and minimal handling of small ocular biopsy samples, while retaining excellent histologic cytomorphology. Supported by the Department of Pathobiology, College of Veterinary Medicine, Auburn University.

ABSTRACT NO.: 19

Ocular examination and diagnostic ophthalmic testing in three species of bat

C. E. Plummer, S. E. Blackwood, K. P. Barrie and D. E. Brooks
Departments of Small and Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA

Purpose:  This study aims to report anterior segment examination findings including values for intraocular pressure (IOP) in both the hanging and upright positions and tear production in healthy specimens of three species of bat.

Methods:  Ten of each of the three species of bat (Pteropus vampyrus, Pteropus pumilus, Pteropus hypomelanus) were examined without sedation or anesthesia. Each animal was manually restrained for examination and data collection. Tear production was measured with the phenol red thread test (PRT) and IOP was assessed via rebound tonometry. IOP measurements were taken with each bat being held upright, followed by repositioning into their normal resting hanging position. Slit lamp biomicroscopy of the anterior segment was performed on each animal.

Results:  Mean tear production was 21.1 ± 10.0 mm/min for P. vampyrus, 19.3 ± 9.9 mm/min for P. pumilus, and 19.2 ± 9.9 m/min for P. hypomelanus. There was a significant difference in tear production between the sexes of P. pumilus and P. hypomelanus with males producing more tears than females, but not between males and females of P. vampyrus. IOP in the upright position was 14.1 ± 3.9 mmHg for P. vampyrus, 18.4 ± 4.5 mmHg for P. pumilus, and 11.7 ± 4.8 mmHg for P. hypomelanus. IOP in the hanging position was 17.9 ± 6.1 mmHg for P. vampyrus, 23.3 ± 5.1 mmHg for P. pumilus, and 16.5 ± 5.8 mmHg for P. hypomelanus. There was a significant difference in IOP between the upright and hanging positions with a higher IOP measurement obtained while the animal is in its hanging position in all three species. Iris-to-iris persistent pupillary membranes are common in these three species of bats, as are cystic proliferations of the posterior pigmented epithelium of the iris at the pupillary margin. Many individuals of both sexes had corneal scarring and many more males had evidence of previous eyelid or third-eyelid trauma.

Conclusions:  This report of the ophthalmic finds of the anterior segment of and the reference values established for PRT and IOP will aid in the examination and diagnostic testing for ophthalmic disease in bats.

ABSTRACT NO.: 20

Ophthalmic examination and findings in adult Red Drum Fish (Sciaenops ocellatus)

P. J. Mohoric and M. E. Stengard
Florida Veterinary Specialists and Cancer Treatment Center, Tampa, FL, USA

Purpose:  The aim of this study was to evaluate the ocular features and intraocular pressure (IOP) in adult Red Drum Fish (Sciaenops ocellatus).

Methods:  All fish were anesthetized with tricaine methanesulfonate (MS-222, Western Chemicals, Ferndale, WA, USA) at 70 parts per million. The anterior segment of all fish eyes were examined with a Finnoff transilluminator and slit-lamp biomicroscopy. Binocular indirect ophthalmoscopy was performed in all eyes to observe the posterior segment. IOP was measured and recorded in both eyes of 13/18 fish and in the right eye only in 1/18 fish using applanation tonometry (27/36 total eyes). Tonometry readings were discarded in 4 fish (8 eyes) due to poor anesthesia and inadequate restraint. The horizontal corneal diameter was measured in all eyes.

Results:  There were 9 male and 9 female fish, all of which were 5 years old. Ophthalmic examination of the anterior segment revealed a horizontal oval-shaped immobile pupil. A characteristically large spherical lens and shallow anterior chamber often exhibiting an aphakic crescent medially was observed. The retina was anangiotic and the fundus ranged in color from white-gray to dark yellow-gray. The optic nerve papilla was horizontally elongated and associated with a prominent hyaloid vessel projecting anteriorly into the vitreous. In 2/36 eyes, 2 mm white translucent cysts in the anterior chamber were identified. Seventeen of the fish had anterior subcapsular opacities in both eyes. These lens opacities were between 1 and 5 mm in diameter and ranged in density from faint to prominent. The subcapsular opacities were central to paraxial. One eye had multifocal lens opacities. The mean horizontal corneal diameter of both eyes was 20.83 ± 1.42 mm. The mean IOP for the right and left eye of fish was 8.69 ± 3.29 mmHg and 6.82 ± 3.19 mmHg, respectively. Mean fish length was 99.05 ± 4.33 cm.

Conclusions:  The ocular features of a group of adult Red Drum Fish were identified. In this population of red drum, anterior subcapsular cataracts were a common finding. The average IOP this population of fish was determined to be 7.82 ± 2.82 mmHg.

ABSTRACT NO.: 21

Intraocular sarcomas in rabbits

S. J. Newman*, L. McPherson*, N. McLean†, S. McCain‡ and R. R. Dubielzig§
Departments of *Pathology, †Small Animal Clinical Sciences, and ‡Exotic Medicine, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA; §Department of Pathology, School of Veterinary Medicine, University of Wisconsin–Madison, Madison, WI, USA

Purpose:  Two cases of a previously unreported intraocular neoplasm are characterized in an 8-year-old male and a 5-year-old female rabbit.

Methods:  Case 1 presented for enucleation of the left globe following a chronic inflammatory disease that resulted in a nonvisual eye. Grossly, there was a perforation in the ventral third of the cornea, and an approximately 10 mm × 7 mm × 5 mm pink mass extended from the anterior chamber through the ventral third of the cornea. Case 2 underwent enucleation of the left globe following a protracted history of lens-induced uveitis, cataract, glaucoma, and a recently confirmed dorsal limbal fibrosarcoma.

Results:  In both cases, histopathology revealed a variably pleomorphic and poorly differentiated invasive intraocular spindle cell neoplasm that was closely associated with lens and lens capsular fragments. Extension through a perforation in the ventral cornea and invasion into periorbital tissues were seen in case 1. Gram stains and polymerase chain reaction failed to detect bacterial organisms or Encephalitozoon cuniculi. Immunohistochemical evaluation showed strong, diffuse expression for vimentin but absence of expression for smooth muscle actin, cytokeratin, desmin, and S100.

Conclusions:  These represent the first two cases of intraocular sarcoma in rabbits. Determination of pathogenesis and behavior will require evaluation of larger case numbers, but long-standing intraocular inflammation and/or traumatic insults to the eye are suspected. The histologic features of these tumors closely resemble those previously reported in cats.

ABSTRACT NO.: 22

Florfenicol pharmacokinetics in tear fluid following intramuscular and subcutaneous administration in ewes

A. Regnier*, V. Laroute*, A. Gautier-Bouchardon†, V. Gayrard*, N. Hagen*, P. R. Cloet‡ and P. L. Toutain*
*UMR 181 Physiopathologie et Toxicologie Expérimentales, INRA, ENVT, Ecole Nationale Vétérinaire, 31076 Toulouse, France; †Agence Française de Sécurité Sanitaire des Aliments, Unité de Mycoplasmologie et Bactériologie, 22440 Ploufragan, France; ‡Schering-Plough Vétérinaire, 92307 Levallois Perret, France

Purpose:  This study aims to determine the florfenicol (Schering-Plough Santé Animale, Segré, France) concentrations achieved over time in the tear film following intramuscular (IM) and subcutaneous (SC) administrations in sheep as possible therapeutic modalities for mycoplasmal ovine keratoconjunctivitis.

Methods:  Nine Lacaune sheep without ocular disease were included in the study. They received an IM and SC administration of 20 mg/kg of florfenicol, using a 2-period crossover experimental design. Blood and tear fluid samples were collected predose and at 10 sampling times following dosing. Florfenicol levels in plasma and tear fluid were measured with high pressure liquid chromatography, and kinetic parameters were determined by a noncompartmental analysis. The minimum inhibitory concentration (MIC) of florfenicol for different stains of Mycoplasma was determined by an agar dilution method.

Results:  After IM administration, florfenicol concentrations in the lacrimal fluid were higher and maintained for a longer time than after SC administration. The lacrimal fluid to plasma concentration ratio was 40.2% and 32.5% after IM and SC administrations, respectively. The MIC of the drug for M. agalactiae isolates ranged from 0.5 to 2 µg/mL. No strains were considered resistant to florfenicol.

Conclusions:  Florfenicol penetrated well into the lacrimal fluid of normal sheep with noninflamed eyes as evidenced from the percentage penetrations observed after IM and SC, but effective tear fluid concentrations higher than the MICs for M. agalactiae were not reached after SC administration.

ABSTRACT NO.: 23

Evisceration in three species of owls

M. Murray*, S. Pizzirani†, F. Tseng* and C. Pirie†
*Bernice Barbour Wildlife Clinic and †Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA, USA

Purpose:  This study aims to describe a modified technique for evisceration in free-ranging owls intended for release to the wild.

Methods:  Evisceration was performed in eight owls (five Eastern Screech Owls [Megascops asio], two Barred Owls [Strix varia], and one Great Horned Owl [Bubo virginianus]. All owls suffered severe intraocular injury due to trauma. Evisceration was elected based on poor prognosis for vision and potential for future complications in the injured eye. Contralateral eyes were normal and the birds were considered favorable candidates for release. Owls were anesthetized with isoflurane. After sterile preparation, a limbal incision was made, followed by excision of the cornea and complete removal of intraocular tissues. Upon control of hemorrhage, the intraocular space was packed with Gelfoam (Pfizer, New York, NY, USA). Upper and lower eyelid edges were removed and the site was closed in one or two layers.

Results:  All eight owls recovered uneventfully. Average length of postoperative stay in the clinic was 4–5 weeks. Seven birds were released to the wild following resolution of all injuries and flight reconditioning. One died from complications unrelated to the surgery.

Conclusions:  Evisceration in owls with traumatic ocular injury was performed with no short-term postoperative complications. This technique avoids drawbacks associated with enucleation in owls, including potential damage to the ear, optic chiasm, and intraorbital septum, and distortion of the facial disc, which is crucial to sound triangulation and successful hunting.

ABSTRACT NO.: 24

Presence of os opticus in the Azure Jay (Cyanocorax caeruleus) eye

F. Montiani-Ferreira*, A. Salomão†, M. Machado‡, E. M. S. Schmidt§ and A. L. G. Souza§
*Universidade Federal do Paraná, Curitiba, Brazil; †Pontifícia Universidade Católica do Paraná, Paraná, Brazil; ‡Universidade de São Paulo, São Paulo, Brazil; §Universidade Estadual Paulista, São Paulo, Brazil

Purpose:  This study aims to demonstrate the presence of the element entitled os opticus in the Azure Jay (Cyanocorax caeruleus) eye. The Azure Jay is a very popular bird and it is the symbol of the Brazilian state of Parana. It helps sowing the typical pine tree (Araucaria angustifolia) by picking up the pine nut to eat and dropping the seeds to germ. The species is considered as near threatened (IUCN 2006).

Methods:  Two specimen of Azure Jay died at the triage center for wild animals (CETAS; Tijucas do Sul, SC, Brazil). The eyes were enucleated and 0.3 mL of 10% formalin solution was injected into the vitreous body of each eye then immediately plunged in containers with 100 mL of the same fixative for 5 days. The fixed samples were sent to the UFPR's Comparative Ophthalmology Laboratory (Curitiba, PR, Brazil). The eyes were decalcified in formic acid solution during 48 h. Routine histopathologic techniques were performed. In brief, fixed eye tissue pieces were dehydrated though a series of graded alcohols before clearing with xylenes and embedded in paraffin. Sections of 5-µm thickness were stained with hematoxylin–eosin.

Results:  The presence of an osseous element within the sclera and around the optic nerve was noted. This element was identified as os opticus. A bone structure previously described in other Corvidae family species, but found for the first time in the Azure Jay. Its structure, compound compact and trabecular bone, was surrounding by a delicate periosteum.

Conclusion:  Some hypotheses about the os opticus function exist. However, the real function is still unknown, probably because this structure has been poorly investigated so far. This study brings the first report of the presence of os opticus in an important Brazilian member of Corvidae family, demonstrating some unique histologic characteristics. With this finding, the authors want to revitalize the interest about the prevalence of the os opticus in other bird species as well as the study of its development and function.

ABSTRACT NO.: 25

Meningioma with orbital and optic nerve involvement in a dog: report of a case

F. Pineda*, R. Garcia†, M. Solano‡, A. A. Rodriguez§ and T. J. Cummings¶
*Veterinary Ophthalmology Referral Service, México City, Mexico; †Private Clinician, Toluca City, Mexico State, Mexico; ‡Tufts University, Cummings School of Veterinary Medicine, Grafton, MA, USA; §Pathology Ophthalmic Service, Association to Prevent Human Blindness in Mexico, Mexico City, Mexico; ¶Department of Pathology, Duke University Medical Center, Durham, NC, USA

Purpose:  This study aims to describe a case and course of an optic nerve/orbital meningioma in a dog. Meningiomas have a remarkable ability to contain mesenchymal components, including cartilage, bone, myxoid, and xantomatous tissue. Materials. A 9-year-old, mixed-breed male poodle was presented to for evaluation because of ocular exophthalmos, dilated pupil, lack of visual reflexes, conjunctival redness, optic disc protrusion, and swelling, on of the left eye. The patient developed ocular signs over a 3-month period.

Methods:  Initially treated for an orbital abscess, few weeks later the patient had a dental prophylaxis with no improvement of the ocular sings. Blood samples were taken for CBC and chemistry as well as urine test with no evidence of illness. Different schemes of treatment including topical, oral antibiotics, and steroids were prescribed along the course of several weeks with very poor results. An MRI was then suggested in which a very important mass in the orbital cavity involving the optic nerve moving the eye toward the dog's face was found. Once the MRI was performed, the dog had the entire ocular globe and surrounded tissue removed and a silicone prosthesis put in place.

Results:  According to pathology this case exhibited cartilaginous and osseous metaplasia (metaplastic subtype), also noted focal nests of meningioma that invade the optic nerve, focal perineural involvement of a peripheral twig in orbital fat (rarely seen), optic nerve completely demyelinated, and portions of the tumor surrounded by glial tissue. The tumor was not completely removed.

Conclusions:  The ocular signs, course, and radiology and pathology findings suggested a rare case of a meningioma of the optic nerve with involvement of the orbital tissue. The time for the tumor recurrence may be shortened due to the fact that portions of tumor were not removed completely.

ABSTRACT NO.: 26

A comparison of the efficacy of CaraViscTM and Hylartin® as viscoelastic devices in small animal cataract surgery

M. Armour, D. Esson, and G. Lynch
Eye Care for Animals, Tustin, CA, USA

Purpose:  Ocular viscoelastic devices (OVD) are routinely used in order to facilitate intraocular surgery and minimize surgical complications. Hylartin (10 mg/mL (C14H20NNaO11)n) is commonly selected from available OVDs by veterinary ophthalmologists.The purpose of this study was to compare the efficacy of a new synthetic hyaluronic acid-derived viscoelastic (CaraVisc; 18 mg/mL (C14H20NNaO11)n) to Hylartin.

Methods:  Either CaraVisc (n = 35) or Hylartin (n = 35) were randomly assigned to patients undergoing routine cataract phacoemulsification (n = 70). All patients underwent complete ophthalmic examinations immediately pre- and postoperatively, 1 day postoperatively, and 7 days postoperatively. The incidence of postoperative ocular hypertension (> 25 mmHg) as well as the degree of postoperative aqueous cell and flare on day 1 and day 7 were recorded.

Postoperative Results:  For CaraVisc were cell counts (0.85 and 0.24), flare score (1.47 and 0.38) and for hylartin, cell counts (1.36 and 0.5) and flare score (2.11 and 0.78) on post-op day 1 and 7 respectively. Immediate postoperative hypertension (day 1) was identified in 8.5% (3/35) of both patient groups.

Conclusions:  CaraVisc appears to be a safe and effective viscoelastic agent when compared to Hylartin in veterinary patients undergoing cataract phacoemulsification.

ABSTRACT NO.: 27

Bilateral congenital corneal staphylomas and choristomas in a foal

A. Regnier and I. Raymond-Letron
Département des Sciences Cliniques, Ecole Nationale Vétérinaire, Toulouse, France

Purpose:  Congenital corneal staphyloma is characterized by an opaque and ectatic cornea, the posterior surface of which is lined by iris tissue. This report aims to describe the clinical and histopathological features of this congenital malformation associated with corneal dermoids in a newborn foal.

Methods:  A 2-day-old French Saddle filly was presented with an abnormal appearance of both eyes since birth. Ocular findings were almost similar in both eyes. In the dorsal half of each cornea an abnormal cone-shape tissue protruding between the eyelids was apparent. Each lesion was characterized by a pink central area appearing as a fleshy, smooth, conical mass bulging about 10 mm from the dorsal half of the cornea and surrounded at its base by a 2–3 mm peripheral rim of pigmented tissue. The bulbar conjunctiva and anterior sclera appeared normal. The ventral part of each cornea was normal, allowing visualization of posterior structures. On the right side, the lens and fundus appeared normal. A cataractous lens was present on the left side, but B-scan ultrasonography indicated apparently normal retina and vitreous. The globes did not appear enlarged and were not firm on digital palpation. The filly was euthanatized based on a poor prognosis.

Results:  Gross examination of the formaldehyde-fixed specimens cut in half along the sagittal plane disclosed dark tissue on the posterior surface of the conical protrusions. Microphakia and cataract were also identified in the left eye. Histologically, the corneal lesions were similar in both eyes. The protuberant part of each corneal lesion was a large area of corneal ectasia. The ectatic cornea was lined internally by atrophic iris epithelium and externally by a nonpigmented stratified squamous epithelium without keratinization. Descemet's membrane and the endothelium were completely absent in the ectatic cornea but were present in the ventral part of the cornea. At the margin of the ectatic cornea, a zone of dermal-like vascularized connective tissue containing prominent lobular sebaceous units and abortive hair-bulb structures was identified. The posterior segment was devoid of significant lesions. The final pathological diagnosis was congenital corneal staphylomas associated with corneal dermoids.

Conclusions:  Corneal staphylomas and dermoids are two separate and uncommon congenital disorders in both animals and humans. Their association has only been reported once in the foal. Abnormality in neural crest proliferations and migrations may play a causal role in congenital corneal staphyloma.

ABSTRACT NO.: 28

Ocular findings in a herd of Exmoor ponies

C. L. Pinard
Ontario Veterinary College, Department of Clinical Studies, University of Guelph, Guelph, ON, Canada

Purpose:  This study aims to describe the normal ocular findings in Exmoor ponies.

Methods:  A herd of 25 ponies residing in Ontario, Canada, was examined by slit-lamp biomicroscopy, direct and indirect ophthalmoscopy pre- and postdilation with tropicamide 1%.

Results:  Three stallions, 6 geldings, 1 colt, 1 filly, and 14 mares were examined and the age ranged from 6 months to 31 years. Only two geldings were not purebred; they were crossbred with the same Thoroughbred mare. Presumed inheritable conditions noted included macroblepharon, persistent pupillary membranes, iris hypoplasia, cataracts, and optic nerve head colobomas. Of these presumed inheritable traits, cataracts were the most common findings (11/25) with the anterior capsular, subcapsular and cortical location being the most prevalent (8/11). Upon pedigree analysis of affected horses, an autosomal recessive pattern is suggested for the anterior presentation of cataracts. Eleven horses were considered normal but did display nonheritable traits, such as eyelid sarcoid, iris nevus, Mittendorf's dot, hyaloid artery remnants, hyperreflective vitreal strands, asteroid hyalosis, and bullet-hole lesions in the nontapetum.

Conclusions:  The ocular findings in Exmoor ponies resemble findings in other breeds. Although the pedigree analysis may suggest a recessive mode of inheritance for the appearance of anterior cataracts in this breed, further investigations are needed due to the low numbers of horses examined in this study.

ABSTRACT NO.: 29

Normal pH of equine tears in 27 horses using a silicone chip pH meter

A. A. Woodworth*, D. E. Brooks†, C. K. Clark* and M. R. Nimmo*
*Peterson and Smith Equine Hospital, Ocala, FL, USA; †College of Veterinary Medicine, University of Florida, Gainesville, FL, USA

Purpose:  The purpose of this current study was to establish the normal pH range of tears in normal horses using a digital, electronic pH meter.

Methods:  Prospective study using IQ scientific instruments ISEFT, model IQ120 pH meter to measure tear pH in 27 horses (25 Thoroughbreds [13 females, 12 males], 2 Warmbloods [1 female, 1 male]) hospitalized for elective surgery and without any known concurrent ocular disease. Ophthalmic exams were carried out with slit-lamp biomicroscopy. The pH meter was calibrated as per manufacturer's instructions to a pH of 7.0. Tear samples were taken from the medial canthus of the left eye using 20µL soda-lime glass capillary tubes. Two drops of tears were immediately transferred to the silicone chip plate of the pH meter. A limited number of samples were also taken in the same manner. Ocular diseases sampled from horse eyes with stromal abscesses, corneal ulcers, and melting corneal ulcers with amniotic implantation.

Results:  pH of tears ranged from 7.1 to 7.9 with a mean of 7.5 ± 0.5. Diseased eye pH ranged from 7.0 to 8.1.

Conclusion:  The normal pH of equine tears in this study was lower than previously reported. There is only one unpublished report on the pH of equine tears. That report found a mean pH of 8.33, as measured with pH paper, with no statistical difference between left and right eyes. A cursory look at diseased eye pH indicates a great degree of variation depending on the disease present. Knowledge of normal equine ocular pH and the pH expected with various ocular diseases may be helpful in determining efficacy and prescription of common ocular medications.

ABSTRACT NO.: 30

PCR-mediated detection of bovine papillomavirus E5 and L1 DNA in equine eosiniphilic conjunctivitis/keratitis

C. Kainzbauer*, R. Steinborn†, G. Mair-Scorpio†, P. Benz*, S. Brandt* and B. Nell*
*Department of Small Animals and Horses, University of Veterinary Medicine, Vienna, Austria; †VetOMICS Core Facility, University of Veterinary Medicine, Vienna, Austria

Purpose:  A 17-year-old Icelandic mare was presented with a 4-week history of bilateral mucous to purulent discharge, blepharospasm, erosions on the lids, and red and swollen conjunctivas, the left eye being predominantly affected. On ophthalmologic examination the tentative diagnosis of eosinophilic conjunctivitis/keratitis and infiltration of skin was made and subsequently confirmed by cytology and histology of corneoconjunctival and skin biopsies. To test for a hypothesized presence of bovine papillomavirus type 1 or 2 (BPV-1, BPV-2), conjunctiva and skin specimens collected from each eye were screened for the presence of DNA and transcripts of the viral oncogene E5.

Methods:  Tissue samples were subjected to DNA extraction by using Qiaex DNeasy Blood & Tissue Kit (Qiagen). Routine beta-actin polymerase chain reaction (PCR) testified for successful DNA isolation. Subsequently, PCR was carried out by using BPV-1/-2 consensus primers. In addition, affected conjunctiva from the left eye was subjected to RNA purification. Following successful DNase-digestion, RT-PCR was carried out by using BPV-1/-2 E5-specific primers and EVAgreen as fluorescent dye.

Results:  BPV-1/-2 PCR revealed the presence of E5 DNA in the predominantly affected conjunctiva from the left eye and in periocular skin from the right eye. Conjunctiva of the right eye and periocular skin from the left eye scored negative for E5. Success of PCR was further confirmed by using sarcoid DNA as positive control. RT-PCR from DNA-free RNA revealed that the E5 gene is also transcribed in conjunctiva of the predominantly affected left eye. DNA and RNA isolated from skin of apparently healthy horses as negative controls scored consistently negative throughout experiments.

Conclusion:  This is the first report describing the successful detection of BPV-1/-2 E5 DNA and mRNA transcription of this viral oncogene in a case of eosinophilic conjunctivitis/keratitis. This finding is not so surprising since previously obtained data indicate a possible involvement of BPV in nonsarcoid equine skin disorders and ocular squamous cell carcinoma (Kainzbauer and Brandt, Proceedings of the joint ESVONC and VCS Meeting, February 28–March 1, 2008, Copenhagen, p. P11). Additional experiments conducted on a larger group of patients suffering from eosinophilic conjuctivitis/keratitis are warranted to investigate whether BPV contributes to disease initiation and/or maintenance.

ABSTRACT NO.: 31

The use of piroxicam as an adjunctive treatment for squamous cell carcinoma in the third eyelid of a horse

S. Iwabe*, L. Ramirez-Lopez† and M. Juárez-Sánchez†
*Department of Pharmacobiology, Centro de Investigación y de Estudios Avanzados del IPN, Mexico City, Mexico; †Department of Equine Medicine, School of Veterinary Medicine, UNAM, Mexico City, Mexico

Purpose:  Evaluate the use of piroxicam as an adjunctive treatment for squamous cell carcinoma in a horse.

Material and methods:  In September 2007, a 10-year-old chestnut Thoroughbred gelding weighing 555 kg was presented for evaluation of presumed granulation tissue in the third eyelid of the left eye. The initial treatment consisted of antibiotics and anti-inflammatory medications, and a biopsy from the granulation tissue in the third eyelid was taken. The laboratory reported a nontumoral epithelial hyperplasia. After 10 days of treatment, the follow-up findings reported a slight decrease in size of the granulation tissue. After 2 weeks no improvement was observed, so surgical intervention was chosen.

Results:  The third eyelid of the left eye was excised completely and the tumor was submitted for histopathological examination. The laboratory findings reported squamous cell carcinoma. Postsurgical treatment included topical antibiotics and anti-inflammatory drugs, and piroxicam (80 mg p.o. once daily). Ten months following surgery, the horse has not showed any complications nor signs of recurrence.

Conclusion:  Squamous cells carcinoma has been reported as the second most common tumor in horses. Nonsteroidal anti-inflammatory drugs are potent inhibitors of the cyclooxygenases (COX) and COX-2 is overexpressed in a number of epithelial tumors. Therefore, inhibitors of COX-2 may act to induce apoptosis in tumor cells and inhibit angiogenesis.

ABSTRACT NO.: 32

Transcleral delivery of antiglaucoma drugs: pharmacokinetics and pharmacodynamics in normotensive rabbits

T. M. Fife*, C. Mendes†, G. C. Matsutani†, P. M. Evans*, G. G. Gum‡, R. H. Scagliotti* and R. A. P. Carvalho§
*Eye Care for Animals, Tustin, CA, USA; †T Biopolymers, São Paulo, Brazil; ‡Biological Test Center, Irvine, CA, USA; §T Ophthalmics, Irvine, CA, USA

Purpose:  An episcleral drug delivery device (ESDDD) to maintain therapeutic concentrations of drug was tested in normotensive rabbits to examine the effect of these drugs on intraocular pressure (IOP).

Methods:  Animals (n = 4 per group) were implanted on the right eye at day 1 with an ESDDD containing dorzolamide, timolol, latanoprost, diltiazem, captopril, or brimonidine; left eyes were used as control. The IOP was checked using a pneumatonometer in the first hours following implantation and twice a day (morning/afternnon) days 2, 3, 5, 8, 15, and 22. In vitro studies were carried out to characterize the release patterns of the drugs. Drug concentration was measured in samples of aqueous humor at selected time points. The main outcome was the area under the IOP-time curve (AUC) for each animal from day 2 up to day 22. Mean AUC was compared statistically between tested and control eyes (P ≤ 0.05).

Results:  All the formulated implants achieved at least 10–22 days of continuous drug delivery in vitro. Latanoprost exhibited signs of degradation in vitro during elution experiments and, therefore, was excluded from the analyses. The IOP transiently increased in the implanted eyes immediately after surgery for the first 4 to 6 h, then decreased versus control eyes. In comparing the IOP-lowering effect over time (Days 2 to 22) as represented by the AUC, implanted versus fellow eyes, eyes exposed to dorzolamide (P = 0.03) and diltizem (P = 0.0073) demonstrated significantly lower IOP than control eyes. Although not significant, the IOP of eyes exposed to captopril (P = 0.07) and timolol (P = 0.08) were consistently below controls. Brimonidine showed the mildest effect after transscleral delivery. The maximum IOP lowering effects for the studied drugs were: 4.8 mmHg (dorzolamide, day 22); 4.5 (timolol, day 22); 6.9 (diltiazem, day 8); 7.0 (captopril, day 3); and 4.5 (brimonidine, day 15). The IOP effects correlated with the drug elution patterns of the drug-loaded ESDDD.

Conclusions:  Transscleral drug delivery is a suitable route to provide therapeutic drug concentrations to the ocular tissues involved in glaucoma and aqueous humor dynamics. This study showed that drugs regularly used as topical agents and other IOP-lowering agents not used topically can benefit from this route of drug delivery. Supported by the Vision for Animals Foundation Grant. CI: P (RAPC), E (CM, GCM).

ABSTRACT NO.: 33

Treatment of ocular, nasal, and dermatologic disease attributable to feline herpesvirus 1 with oral famciclovir: 23 cases

S. M. Thomasy* and D. J. Maggs†
*Veterinary Medical Teaching Hospital and †Department of Surgical and Radiological Sciences, University of California, Davis, CA, USA

Purpose:  This study aims to investigate the safety and efficacy of orally administered famciclovir in cats with spontaneously occurring disease attributable to naturally acquired feline herpesvirus 1 (FHV-1) infection.

Methods:  Records of cats treated with famciclovir (Famvir®, Novartis) between 2006 and 2008 were reviewed. Complete ophthalmic or dermatologic examination was performed in all cats.

Results:  A total of 23 cats met inclusion criteria. Median (range) patient age was 4.5 years (10 days to 16 years). No gender or breed predisposition was noted. The most common abnormalities were conjunctivitis (87%), keratitis (70%), nasal discharge and/or sneezing (43%), blepharitis (39%), and dermatitis (13%). The median (range) dose of famciclovir was 93 (70–141) mg/kg, administered orally TID. Median (range) duration of therapy was 14.5 (7–63) days. Median (range) period of follow-up was 34.5 (5–422) days. The most common concurrently administered medications were topical antibiotics (83%), oral lysine (48%), systemic antibiotics (39%), and topical antivirals (35%). Clinical signs improved markedly in 17 cats (74%) and mildly in 4 cats (17%). No improvement was noted in 2 cats (9%). These cats were subsequently diagnosed with periocular Malasseziasis and bacterial pyoderma (n = 1) and idiopathic sclerosing orbital pseudotumor (n = 1). Adverse effects potentially attributable to famciclovir administration were noted in 3 cats and included anorexia (n = 2) and polydipsia with concurrent decrease in urine specific gravity (n = 1).

Conclusions:  Preliminary data suggest famciclovir (90 mg/kg TID) is a generally safe and effective treatment for spontaneously occurring herpetic disease in cats naturally infected with FHV-1.

ABSTRACT NO.: 34

Oxidative stress in glaucomatous retinas of dogs

D. S. Zirofsky, J. E. Madl and J. R. Gionfriddo
Colorado State University, Fort Collins, CO, USA

Purpose:  Previous research (Chen et al. 2008) has indicated that there are decreased levels of glutamine synthetase (GS) in canine glaucomatous retinas which may contribute to neuronal damage. Oxidative stress may decrease GS levels. Our current project tests if oxidative stress is increased in eyes that have decreased GS.

Methods:  Glaucomatous canine eyes were obtained from Comparative Ocular Pathology Laboratory of Wisconsin and evaluated for oxidative stress using immunohistochemical staining for malondialdehyde (MDA). The density of staining for markers for oxidative stress was compared in retinas with different levels of GS staining.

Results:  Staining density for MDA was not statistically different for control retinas (n = 6) versus retinas with previously identified homogenously low GS staining (which generally corresponded to more damaged or chronically affected retinas) (n = 6). There were patchy areas with higher staining densities for MDA in the retinas that were identified as having patchy staining for GS and glutamate. These areas were either less damaged or more acutely affected retinas (n = 5).

Conclusions:  Oxidative stress was not increased in severely damaged glaucomatous retinas that generally had decreased GS staining. However, there were patchy areas of oxidative stress in the glaucomatous retinas that were less severely damaged and had patchy GS staining. Colocalization techniques are necessary to determine whether there is concurrent oxidative stress in areas with decreased glutamine synthetase. Supported by ACVO Foundation Grant.

ABSTRACT NO.: 35

Surgical treatment and outcome in a case of persistent hyperplastic primary viterous/tunica vasculosa lentis in a dog

C. G. Pirie*, S. Pizzirani* and J. Keating†
Departments of *Clinical Sciences and †Biomedical Sciences, Tufts Cummings School of Veterinary Medicine, North Grafton, MA, USA

Purpose:  This study describes the surgical treatment of persistent hyperplasic primary vitreous/tunica vasculosa lentis (PHPV/PHTVL) in a dog.

Methods:  A 3-year-old male Labrador presented for acute redness and blepharospasm in the left eye. On examination, periocular and conjunctival hyperemia, associated with trace flare and slight miosis in the left eye was noted. Menace, dazzle, and pupillary light reflexes were present. Intraocular pressure was low (7 mmHg). Anterior segment examination revealed axial, intralenticular dense pigmentation, associated with hemorrhage and cataractous changes. The marginal equatorial lenticular zone was unaffected and anterior lens capsule was intact. Ocular ultrasound revealed intralenticular hyperechogenicity, with posterior lenticonus and a focal hyperechoic structure emanating from the posterior capsule, suggestive of PHPV/PHPVL (grade VI). Differential included intralenticular melanoma secondary to congenital vascularization. Color Doppler failed to identify active blood flow. Phacoemulsification and posterior capsulorrhexis, due to presence of a large, vascularized hard plaque was performed. Despite use of wet-field cautery, intravitreal hemorrhage occurred.

Results:  Hematoxylin–eosin stain of the posterior plaque/capsule revealed collagen deposition, with mineralization, cholesterol clefts, lymphoid aggregates, hemosiderophages, and discontinuity of the capsule. Serial clinical reexaminations noted fresh vitreal hemorrhage, subsequently migrating into the anterior chamber. During this period, menace and dazzle reflex were absent; however, intraocular pressure was within normal limits. One month following surgery and oral steroids, vitreal hemorrhage was nearly resorbed, with no hyphema or retinal detachment. Menace and dazzle reflex were present. Five months postoperatively, the dog remains visual.

Conclusions:  Despite potential intra/postoperative complications, phacoemulsification should be considered for treatment of PHPV/PHTVL, as successful outcomes may be attainable.

ABSTRACT NO.: 36

In vitro efficacy of an ophthalmic drug combination against corneal pathogens of horses

G. Ben-Shlomo, C. Plummer, K. Barrie and D. Brooks
Department of Small and Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA

Purpose:  This study aims to evaluate the in vitro efficacy of an ophthalmic drug combination (DC) against proteinase activity and common corneal pathogens of horses.

Methods:  Multiple representative isolates of three bacterial (β-hemolytic Staphylococcus spp., α-hemolytic Streptococcus spp., and Staphylococcus aureus) corneal pathogens of horses were subjected to minimum inhibitory concentration (MIC) testing of a DC that consisted of equal volumes of natamycin 3.33%, tobramycin 0.3%, and cefazolin 5.5%. Proteinase inhibitory activity of the DC was assessed by use of a fluorescence microplate assay with gelatin and collagen I as substrates. The MICs of the DC were compared with those for each of the component medications and antiproteinase activity of the DC was compared with that of serum by use of paired t-tests and a one-way analysis of variance, respectively.

Results:  The DC did not inhibit the collagenase and proteinase activity compared to the control (P > 0.49). The three bacterial pathogens were susceptible to both the drug mix and cefazolin alone. One of four isolates of S. aureus was resistant to tobramycin alone, but the rest of the isolates showed susceptibility to tobramycin alone. Nevertheless, the concentration of cefazolin needed to inhibit the α-hemolytic streptococcus was significantly higher in the DC compare to cefazolin alone (P ≤ 0.0002). On the other hand, the concentration of tobramycin in the DC was lower than when used alone, yet this difference was not statistically significant (P > 0.19).

Conclusions:  This drug combination is an effective antibacterial treatment against common corneal pathogens of horses. Nevertheless, the DC was not effective as an antiproteinase treatment; hence, complimentary antiproteinase treatment should be administered. Drug combinations have the potential of minimizing the time, stress, and fatigue associated with topical treatment regimens consisting of multiple drugs used separately for horses with keratitis. Supported by the American Quarter Horse Foundation grant.

ABSTRACT NO.: 37

Digital infrared photography of the anterior segment of the equine eye

R. J. McMullen Jr and B. C. Gilger
Department of Clinical Sciences, North Carolina State University, Raleigh, NC, USA

Purpose:  This study aims to demonstrate benefits of digital infrared of the anterior segment of the equine globe.

Methods:  Normal and diseased anterior segments were photographed with a digital infrared Nikon D70 camera (Nikor 18–55 mm AF or 105 mm macro lenses) converted by LifePixel (http://www.lifepixel.com) for infrared imaging (wavelength > 760 nm). Color images were taken with a Nikon D200 digital SLR camera with a Tamron 90 mm macro lens and a Nikon SB-800 flash.

Results:  The normal, brown equine iris appeared grayish-blue with variable amounts of dark blue foci throughout the iridal surface. The darker the original tissue, the deeper the blue color. Infrared images of heterochromic eyes appeared darker than color images. Infrared images were rich in contrast, and the pupil was easily identifiable as a black ellipse surrounded by pupillary ruff. Pigmented masses within the anterior chamber were readily visible even with corneal opacification. Corneal edema was visually eliminated and some opacifications become transparent allowing for better evaluation of their position within the cornea and corneal vessels and other isolated opacifications appeared to be suspended above the iris and easily visualized.

Conclusions:  Increased contrast using infrared photography and ability to visualize anterior iris through an opaque cornea is a valuable method to evaluate the pupil and assess effects of inflammation in eyes with uveitis and/or glaucoma.

ABSTRACT NO.: 38

Ulcerative eosinophilic keratoconjunctivitis in three horses: clinical course and characterization by electron microscopy

C. A. Sandberg, I. P. Herring, J. J. Schorling, J. P. Pickett and T. LeRoith
Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University

Purpose:  This study aims to describe the clinical course, histopathologic, scanning electron microscopic and dermatological findings of three horses with eosinophilic keratoconjunctivitis.

Methods:  Prospective study of clinical cases presented to the ophthalmology service at the VMRCVM Veterinary Teaching Hospital.

Results:  Three horses, ranging in age from 2 to 9 years, were presented in summer months over a 2-year period for ulcerative keratitis associated with eosinophilic keratoconjunctivitis. Medical treatment with topical antimicrobials, topical and systemic steroids, systemic nonsteroidal agents, calcineurin inhibitors, mast cell stabilizers and interferon 2α was unsuccessful in resolving the corneal ulceration. In all cases, superficial keratectomy resulted in rapid healing of the epithelial defects. Histopathology of the keratectomy specimens revealed hyper-eosinophilic granular material and an acellular hyalinized zone in the anterior corneal stroma. Transmission electron microscopy performed in two cases revealed amorphous debris bordering or within the anterior corneal stroma that represented disrupted eosinophils, eosinophilic proteins or lytic collagen. Allergic skin disease was documented by a veterinary dermatologist in two cases. Recurrence of eosinophilic disease was documented in one horse.

Conclusions:  Healing of corneal ulcers associated with eosinophilic keratoconjuncitivitis may be facilitated by superficial keratectomy. There may be an association between eosinophilic keratoconjuncitivitis and allergic disease in some horses.

ABSTRACT NO.: 39

A retrospetive study of performance changes in horses that have undergone unilateral enucleation

K. L. Wotman, M. E. Utter and K. R. Covert
New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA

Purpose:  This study aims to compare the performance level of horses who have undergone unilateral enucleation for a variety of ocular diseases including: corneal ulceration, stromal abscess, uveitis, corneal rupture, and squamous cell carcinoma.

Methods:  Records of horses that have had unilateral enucleation at the University of Pennsylvania's New Bolton Center from 2000–2008 were considered. A survey was generated that included: breed and sex of horse, age at the time of surgery, eye enucleated and reason for removal, vision remaining at the time of surgery, preoperative occupation, and return to previous performance level after surgery. Contact persons (owner, trainer, referring veterinarian) were telephoned and results recorded in a data table.

Results:  A total of 82 enucleations were performed over the 8-year period. Forty-seven cases were lost to follow-up due to a variety of reasons including: change of ownership, incorrect number, or unreturned phone calls. Two horses were euthanized unrelated to enucleation. Thirty-three horses were included in the study. Thirty-one horses returned to previous performance level immediately postoperatively including: flat racing, eventing, steeplechase, jumping, dressage, driving, and pleasure horses. Age ranges were from 2 months to 28 years and 15 breed types were represented. Two horses did not return to previous performance after enucleation which was directly related to loss of vision in one eye.

Conclusions:  Horses are able to return to a variety of occupations after unilateral enucleation and their performance level should not be affected.

ABSTRACT NO.: 40

The mouse harderian gland

T. Forest, N. J. McKinnon and R. L. Peiffer
Merck & Co. Inc.

Purpose:  This study aims to review the structure and function of the mouse harderian gland, and to characterize and evaluate the occurrence and type of incidental lesions present in the mouse harderian gland within a select population.

Methods:  A population of CRL:CD1(ICR) mice in control groups with a study period discontinued date between January 1, 1998, and February 1, 2008, at the Merck West Point Research Laboratories were selected, for a total population of 4,190 animals. Histopathology samples with previously diagnosed incidental pathological lesions of the harderian gland were evaluated, for a total of 94 samples evaluated.

Results:  The lipid produced by the horseshoe-shaped mouse harderian gland by exocytosis and is associated with a variety of functions: corneal protection, lubrication, thermoregulation, solvent properties, and bactericidal effects. The release mechanism and function of porphyrin produced is not completely understood, Stored as solid intraluminal secretions porphyrin is considered to have photoprotection and photoreception properties. Spontaneously occurring lesions of the gland including; lymphocytic cellular infiltration, cystic hyperplasia, adenomas and adenocarcinomas have been reported as incidental findings in various strains of mice. Adenomas, the most common type of incidental lesion present, could be further differentiated into; papillary, cystic papillary, acinar and cystic. Transitional changes may be present from one type to another and/or the coalescing of two types of adenomas. Adenocarcinomas are considered to develop from a focal area of transformation of an adenoma.

Conclusions:  The significance and function of the mouse harderian gland and the effects of incidental lesions could provide areas of further investigation. Supported by Merck & Co. Externship in Laboratory Animal Ophthalmology and Ocular Toxicology 2008.

ABSTRACT NO.: 41

Ocular ultrasound findings in the Asian elephant, Elephas maximus

C. M. Nunnery*, K. P. Barrie*, E. B. Wiedner†, K. J. Gelatt-Nicholson‡, C. E. Plummer* and D. E. Brooks*
*College of Veterinary Medicine, University of Florida, Gainesville, FL, USA; †Ringling Bros. and Barnum and Bailey, Center for Elephant Conservation, Polk City, FL, USA; ‡North Florida Veterinary Radiology, Jacksonville, FL, USA

Purpose:  The ophthalmic examination of the elephant is challenging. Many elephants are difficult to handle and do not tolerate a complete ophthalmic examination. In addition, many older elephants have corneal opacities that hinder ophthalmoscopic examination. The purpose of this study was to determine if ocular ultrasound would be tolerated by elephants and to establish normal ocular ultrasonographic measurements of the Asian elephant.

Methods:  This study included 11 adult Asian elephants. Ocular images were obtained in standing, nonsedated animals using a LOGIQ e ultrasound with a 10-MHz curvilinear probe. Transpalpebral ocular ultrasound was performed on both eyes in the horizontal and vertical directions. Images collected were used to measure the corneal thickness, anterior chamber depth, axial lens thickness, posterior segment depth, and axial length of the globe. The images were measured by two independent examiners to determine repeatability. Data were collected from 22 eyes and a two-way analysis of variance performed.

Results:  The mean corneal thickness was 1.4 mm (± 0.2), anterior chamber depth was 5.5 mm (± 1.0), axial lens thickness was 9.5 mm (± 0.9), posterior segment depth was 20.0 mm (± 1.6), and axial globe length was 36.5 mm (± 1.5). Measurements between examiners were more repeatable when using vertical images.

Conclusions:  Ocular ultrasonic examination in the elephant is a minimally invasive way to examine structures of the eye that may be difficult to visualize. The elephants tolerated the ultrasound examination reasonably well.

ABSTRACT NO.: 42

Normal ophthalmic diagnostic test values in Angora goats

N. C. Whelan* and D. Thompson†
*Ontario Veterinary College, University of Guelph, Guelph, ON, Canada; †Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand

Purpose:  This study aims to document normal values for tear production, corneal touch threshold (CTT) and intraocular pressure (IOP) in healthy Angora goats.

Methods:  Schirmer tear test (STT I) values and IOP measurements were obtained from 69 Angora goats ranging in age from 5 months to 5 years. STT I values following topical anesthetic (STT Ia) and corneal touch thresholds were obtained from 10 yearling goats. CTT were obtained using a Cochet-Bonet esthesiometer with measurements taken on three separate occasions 1 month apart. IOP was measured using an applanation tonometer (Tonopen®).

Results:  For the 69 goats, the mean STT I reading was 18 mm ± 4 mm wetting/min (range 11–30). For STT Ia values, pretreatment STT I readings were 21 ± 5 mm wetting/min. Following treatment with topical anesthetic, STT Ia values were 10 mm ± 5 mm wetting/min. Mean CTT readings in mm (mean pressure in g/mm2) were Central 25 (1.8), Dorsal 19 (2.8), Ventral 22 (2.2), Nasal 22 (2.2), and Temporal 21 (2.4). Mean IOP was 13.9 ± 2.4 mmHg (range 8–20 mmHg).

Conclusions:  The Angora goat has similar ranges of STT I values to other species. CTT is lower then in people, dogs, rabbits, and cats and about the same as the horse. Mean IOP in the Angora goat was slightly higher than found in the adult Pygmy goat. However, it was lower than that found in the dog, cattle, horse, zebra, and ibex, but higher than in the cat and oryx. Supported by the Institute of Veterinary, Animal and Biomedical Sciences, Massey University, and Ontario Veterinary College, University of Guelph.

ABSTRACT NO.: 43

Ocular biometry in a colony of Saanen goats with different ages

A. P. Ribeiro, L. S. Miguel, P. R. Juliana, I. A. M. A. Teixeira, A. L. G. Souza and J. L. Laus
Faculty of Veterinary Medicine and Agricultural Sciences, Sao Paulo State University, Jaboticabal, Brazil

Purpose:  This study aims to determine the lens thickness, anterior and vitreous chamber depths and axial globe length in goat eyes at different ages.

Methods:  B- and A-modes (Ultra Scan, Alcon, Irvine, CA, USA) ultrasonography was performed in 55 (110 eyes) healthy Saanen goats aging 45 (n = 15), 180 (n = 20), and 549 days (n = 20). All subjects received ophthalmic examinations prior to ultrasonography to verify the absence of ocular lesions. Lubricating jelly as a stand-off pad, was placed on the 20 MHz transducer tip after instillation of a topical anesthetic (Anestalcon, proximetacaina, Alcon do Brasil). The transducer was placed in horizontal position until optimal B-scan images, according to echoes of the A-mode, were obtained. The anterior chamber depth (AC) was measured as the distance between echoes from the posterior corneal surface and the anterior lens surface. The lens thickness (L) was the distance between echoes from the anterior and posterior lens surfaces. The vitreous chamber depth (V) was the distance between echoes from the posterior lens surface and retina. The axial globe length (AL) was measured from the posterior corneal surface to the retina. For all measurements the gain and the velocity of sound was set at 78 dB and 1532 m/s, respectively. One-way analysis of variance with Tukey post-hoc test was carried out to compare the ecobiometric readings among subjects (P < 0.05).

Results:  Mean and standard deviation of the ocular structures for the goats aging 45, 180, and 549 days were, respectively, 2.77 ± 0.32, 3.12 ± 0.42, 3.44 ± 0.37 mm (AC); 6.37 ± 0.36, 7.70 ± 0.28, 8.70 ± 0.28 mm (L); 10.31 ± 0.35, 10.90 ± 0.42, 12.16 ± 0.61 mm (V); and 19.45 ± 0.63, 21.72 ± 0.62, 24.24 ± 0.83 mm (AL). Ocular measurements between right and left eyes were not significantly different among subjects of the same age (P > 0.05). All parameters evaluated (AC, L, V, and AL) increased significantly with age (P < 0.01).

Conclusions:  Anterior chamber, lens, vitreous chamber and axial globe length increase with age in the Saanen breed. The knowledge of normal ocular dimensions facilitates the use of ultrasonography in the evaluation of ocular disease in Saanen goats. Grant support: Suported by Fundação de Amparo à Pesquisa (FAPESP).

ABSTRACT NO.: 44

Placement of an intrasleral hydroxyapatite sphere and cosmetic corneoscleral prosthesis in a growing dog

E. S. Storey and R. T. Carter
School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA

Purpose:  This study aims to determine if a modification of previous surgical techniques could be used to place a hydroxyapatite sphere intrasclerally in preparation for progressively larger corneoscleral prostheses in a young dog.

Methods:  A 5-month-old male Weimaraner puppy presented following an ocular injury that blinded the right eye by inducing a retinal detachment. Corneal fibrosis, cataract, uveitis, and early phthisis bulbi were also noted. Progressive phthisis was anticipated and the owner was determined to pursue the most cosmetic approach to preventing continued uveitis and phthisis bulbi. A corneoscleral prosthesis was chosen because it was the only option that would preserve the normal cosmetic appearance and progress with the growth of the young dog. A dorsal conjunctival peritomy was completed to expose the dorsal sclera 5 mm behind the limbus. The globe was eviscerated and a 6-mm diameter circle of sclera and optic nerve tissue were removed from the posterior globe to provide vascular access to the implant without disturbing the insertions of the rectus muscles. The hydroxyapatite sphere was placed in the sclera and the sclera closed with a simple continuous pattern of 6-0 PDS. Corneal epithelium was debrided with the help of absolute alcohol. The conjunctival peritomy was continued 360 degrees and closed over the debrided cornea with a simple continuous pattern of 8-0 vicryl. A temporary corneoscleral prosthesis provided with the hydroxyapatite sphere was placed anterior to the globe and a temporary tarsorraphy was placed until the ocularist could evaluate the dog 10 days later.

Results:  The conjunctiva adhered to the corneal stroma providing a resilient, healthy, nonulcerated surface for the corneoscleral prosthesis. The original prosthesis was replaced with a progressive series of corneoscleral prostheses corresponding with the palpebral fissures of the growing dog. The ocularist chose not to use a prosthesis mounted to a post implanted into the hydroxyapatite implant because mobility was excellent without it. No complications were encountered in the postoperative follow-up for 1 year.

Conclusions:  It is possible to use a hydroxyapatite sphere as an intrascleral implant. This minimizes surgical time and trauma to the orbit and rectus muscles while providing a vascularized instrascleral implant that is compatible with a postmounted corneoscleral prosthesis. Covering the cornea with a conjunctival flap resulted in a resilient surface that tolerated the presence of the corneoscleral prosthesis well. Excellent cosmesis was achieved for this growing dog despite enucleation by providing progressively larger corneoscleral prostheses.

ABSTRACT NO.: 45

Effects of silver sulfadiazine and povidone-iodine on in vitro replication of feline herpesvirus-1

M. E. Coster*, J. Stiles*, S. G. Krohne * and R. M. Pogranichniy†
Departments of *Veterinary Clinical Sciences and †Comparative Pathobiology, School of Veterinary Medicine, Purdue University, West Lafayette, IN, USA

Purpose:  This study aims to determine effects of silver sulfadiazine (SSD) and povidone-iodine (PVP-I) on in vitro replication of feline herpesvirus-1 (FHV-1).

Methods:  Virus titration was performed to assess FHV-1 titer with SSD (2.5 to 30 µg/mL) or PVP-I (0.01 to 1 mg/mL) present during and after adsorption. Plaque reduction assays were performed by adding SSD (5 to 30 µg/mL) or PVP-I (0.5 to 5 mg/mL) to Crandell-Reese feline kidney cells before, during, or after FHV-1 adsorption. The 50% and 90% inhibitory concentrations (IC50 and IC90) and plaque reduction percentage (PRP) compared to controls were calculated. The effect of PVP-I on extracellular virus was assessed, by incubating FHV-1 with high concentrations of PVP-I for various times before diluting for plaque assays.

Results:  Viral titer was not affected by either 10 µg/mL SSD or 0.25 mg/mL PVP-I. When SSD was present during, but not before or after, adsorption, there was a concentration-dependent reduction in plaques but IC50 was not achieved. At 15 µg/mL SSD, mean ± SD PRP was 45.4 ± 13.9%. There was no effect of 2.5 mg/mL PVP-I on PRP. Cytotoxicity was observed with concentrations of SSD and PVP-I greater than these. When PVP-I was added to extracellular FHV-1 for 30 s prior to adsorption, IC90 was 5 mg/mL.

Conclusions:  Dose-dependent inhibitory effects of SSD and PVP-I on FHV-1 infectivity were demonstrated. Silver sulfadiazine inhibited adsorption of FHV-1; PVP-I was virucidal extracellularly. Higher concentrations of both SSD and PVP-I exhibited cytotoxicity that limited in vitro evaluation of these two compounds.

ABSTRACT NO.: 46

Relative quantitation of leukocyte mitochondrial DNA and mitochondrial evaluation using transmission electron microscopy in normal English Springer Spaniel dogs and those affected with retinal dysplasia

B. S. Bauer*, G. W. Forsyth†, L. S. Sandmeyer* and B. H. Grahn* *Department of Small Animal Clinical Studies, Veterinary Biomedical Sciences; †Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada

Purpose:  This study aims (i) to compare the relative amounts of mitochondrial DNA (mtDNA) in leukocytes of normal and affected English Springer Spaniel dogs using real-time PCR, and (ii) to quantify, measure, and assess morphology of lymphocyte mitochondria in normal and affected dogs using transmission electron microscopy.

Methods:  For relative quantification of mtDNA, genomic DNA was extracted from the leukocytes of affected and normal dogs. Using cytochrome oxidase subunit 1 (COX-1) as a representative of mtDNA, the relative quantification of COX-1 between normal and affected dogs was performed using real-time PCR. For electron microscopy, lymphocytes from affected and normal dogs were examined and the mitochondria within each cross-section were identified, quantified and the mitochondrial surface area (ìm2) per lymphocyte cross-section was calculated. Lastly, using a masked technique, mitochondrial morphology was compared between affected and normal dogs.

Results:  mtDNA amount was variable in normal English Springer Spaniel dogs and ranged from a 1.08-fold to a 4.76-fold difference. Comparison of the affected dogs to a normal dog with the lowest mtDNA amount revealed differences ranging from 1-fold to 2.68-fold. Lymphocyte and mitochondrial surface area, mitochondrial quantification and morphology assessment revealed no significant difference between affected and normal dogs.

Conclusions:  We failed to identify a difference in relative amounts of mtDNA or lymphocyte mitochondrial size, number or morphology between normal English Springer Spaniels and those affected with retinal dysplasia. Supported by the Companion Animal Health Fund.

ABSTRACT NO.: 47

Tonometry in the Florida manatee

G. Ben-Shlomo, D. Brooks, K. Barrie, C. Plummer and D. SamuelsonDepartment of Small and Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA

Purpose:  This study aims to evaluate the intraocular pressure (IOP) in the Florida manatee (Trichechus manatus latirostris).

Methods:  Rebound tonometry (TonoVet™) was performed in both eyes of nine manatees to evaluate the IOP of this unique mammal. The data were collected during captures performed by the Florida Fish and Wildlife Conservation Commission and the U.S. Geological Survey. The evaluations were performed during three captures between December 2007 and February 2008, when manatees congregated in the warm water of Crystal River, Florida. Manatees were captured in nets deployed along the shore by a specialized net boat without the use of sedation or anesthesia.

Results:  None of the eyes were observed to have any abnormal or pathologic conditions. Blood vessels were routinely observed in the cornea. The mean (± SD) IOP was 8.5 (± 2.7) mmHg and the median was 9.5 mmHg. There was no significant difference between the IOP values of the left and the right eyes (P > 0.35). Collecting the IOP measurements was a great challenge, due to the fact that the manatees kept their eyes closed most of the time while outside the water. Most of the animals opened their eyes for about 3–5 s every 1–2 min (during inhalation).

Conclusions:  This is the first report of the IOP values of the Florida manatee. The values of the intraocular pressures in this species are among the lowest known in mammals and exceptionally different from cetaceans, which can range up to 70 mmHg or higher.

ABSTRACT NO.: 48

Tear production in normal juvenile dogs

J. J. Broadwater*, S. M. Carastro*, C. M. H. Colitz* and F. Elvinger†
*Animal Eye Specialty Clinics of South Florida, Miami, FL, USA; †Department of Large Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA, USA

Purpose:  This study aims to determine tear production in normal juvenile dogs.

Methods:  Fourteen healthy puppies of various breeds between 67 and 115 days of age underwent complete ophthalmic examinations to exclude ocular disease that might alter tear production. Schirmer tear test 1 (STT1) was performed in both eyes of each subject for one minute. Immediately after the completion of STT1, ophthalmic proparacaine hydrochloride (0.5%) was applied to both eyes. One minute after application of proparacaine, the residual tear volume in the ventral conjunctival sac was absorbed with a cotton tip applicator. Schirmer tear test 2 (STT2) was then performed in both eyes of each subject for one minute.

Results:  Twelve intact males and two intact females were included in this study. Ages ranged from 67 to 115 (mean ± SD: 82.3 ± 13.62) days and weights ranged from 1.1 to 4.4 (2.1 ± 0.98) kg. STT1 results ranged from 17 to 26 (20.5 ± 2.77) mm/min in the left eye, and 15 to 25 (19.4 ± 3.32) mm/min in the right eye. STT2 results ranged from 3 to 21 (10.1 ± 5.91) mm/min in the left eye and 5 to 24 (10.9 ± 6.04) mm/min in the right eye.

Conclusions:  These results did not differ greatly from previously published STT1 and STT2 results of adult dogs. Juvenile dogs have similar tear production to adult dogs.

ABSTRACT NO.: 49

Comparison of the effects of serum from nondiabetic dogs versus diabetic dogs on the growth of Pseudomonas aeruginosa in vitro

C. H. Chapman*, J. G. Songer† and D. Esson‡
*Eye Care for Animals, Maricopa, AZ, USA; †Department of Veterinary Science and Microbiology, University of Arizona, Tucson, AZ, USA; ‡Eye Care for Animals, Tustin, CA, USA

Purpose:  The purpose of this study was to evaluate potential differences in the effects of serum from diabetic serum versus nondiabetic animals, on the growth of Pseudomonas aeruginosa in vitro.

Methods:  Blood was collected aseptically from 10 diabetic dogs and 10 nondiabetic dogs. To isolate the effect of glucose, a third group, nondiabetic, hyperglycemic serum (using additional 300mg/dL of dextrose) was used as a control. A complete blood count, blood chemistry, and fructosamine assay were performed on each patient. Standard aliquots of 0.10 µL of P. aeruginosa broth was added to each serum sample, and the mixture was then incubated 4 h at 37 °C. Serial 10-fold dilutions were plated on tryptose agar with 5% defibrinated sheep blood, incubated at 37 °C for 24 h, and numbers of CFU determined. Each sample was examined in triplicate.

Results:  The mean number of CFU in serum from diabetic dogs was 107.26 with a median of 107.19. The non-diabetic group had a mean number of CFU of 106.99 with a median of 107.04. The mean number of CFU in the nondiabetic, hyperglycemic group was 107.14, with a median of 107.11.

Conclusions:  No statistically significant difference was found between the effect of serum from diabetic versus nondiabetic dogs on growth of P. aeruginosa in vitro. These results suggest that there may be no deleterious effects of using serum from diabetic dogs to treat malacic corneal ulcers.

ABSTRACT NO.: 50

Effect of topical benoxinate-fluorescein combination on bacterial cultures from the conjunctiva of normal dogs

S. A. Ivins*, P. A. Gerding† and J. G. Songer‡
*Eye Care for Animals, Santa Fe, NM, USA; †Eye Care for Animals, Chicago, IL, USA; ‡Department of Microbiology and Veterinary Sciences, University of Arizona, Tucson, AZ, USA

Purpose:  The purpose of this study was to evaluate the effect of topical benoxinate-fluorescein combination solution on bacterial culture growth taken from the conjunctival fornix of 30 normal dogs.

Materials and methods:  Dogs were considered normal after an ocular examination. Baseline cultures were taken prior to instillation of a balanced salt solution (BSS) (control) or a topical benoxinate-fluorescein combination solution. In each dog, the benoxinate-fluorescein combination was placed in a randomly selected eye and BSS in the fellow eye. Serial culture collection was performed at 2 min, 5 min, and 15 min after instillation of the designated test substance for each eye. All cultures were plated on blood agar and cultured for 24 h at 37 °C. The number of bacterial organisms was determined by a standard plate count method.

Results:  There was no significant difference found between the test substances. Over time, the means for benoxinate-fluorescein tended to weakly increase, whereas, the means of BSS tended to weakly decrease; however, the logarithmic counts showed no real change between successive times, when all negative cultures were excluded.

Conclusion:  The benoxinate-fluorescein combination used in this study did not appear to significantly decrease bacterial growth from the conjunctiva of normal dogs.

ABSTRACT NO.: 51

Effects of topically applied serum on healing rate of spontaneous chronic corneal epithelial defects in dogs

J. S. Eaton*, S. R. Hollingsworth*, B. J. Holmberg†, M. H. Brown†, P. J. Smith‡ and D. J. Maggs*
*Veterinary Medical Teaching Hospital, University of California, Davis, CA, USA; †Veterinary Ophthalmology Services Inc., Little Falls, NJ, USA; ‡Animal Eye Care, Fremont, CA, USA

Purpose:  This study aims to determine effects of topical administration of canine serum on healing rate of spontaneous chronic corneal epithelial defects (SCCED) in dogs.

Methods:  Dogs with unilateral SCCED were randomly assigned to receive topical saline or serum collected from healthy dogs free of blood-borne infectious disease and with normal hematological and biochemical profiles. Dogs with bilateral SCCED, keratoconjunctivitis sicca, or previously treated with topical serum, grid/punctate keratotomy, or superficial keratectomy were excluded. Dogs meeting entry criteria underwent blunt epithelial debridement and were topically treated with serum or saline (TID), tobramycin (TID), and atropine (EOD), and were reevaluated at weekly intervals for 3 weeks or until corneas no longer retained fluorescein. At each reevaluation, dogs with unhealed SCCED underwent blunt debridement and grid keratotomy. Owners and investigators were masked as to treatment group. Outcomes were compared using chi-squared analysis, Student's t-test or their nonparametric equivalents.

Results:  A significant difference was not detected between the two treatment groups with respect to age (P = 0.55), gender (P = 0.72), neuter status (P = 1.0), eye affected (P = 1.0), duration of SCCED prior to referral (P = 0.91), degree of vascularization at presentation (P = 0.34), or change in vascularization during treatment (P = 0.89). Median time to healing for dogs receiving serum (2 weeks) or saline (2 weeks) was not significantly different (P = 0.71).

Conclusions:  Preliminary data suggest that topical application of serum to dogs with SCCED has neither advantageous nor deleterious effects on healing time. Supported by UCD CCAH.

ABSTRACT NO.: 52

An evaluation of one method for management of refractory corneal epithelial erosions: a 3-year retrospective study

M. L. Landis and R. L. Peiffer
Bucks County Animal Ophthalmology, Langhorne, PA, USA

Purpose:  The objective of this study is to analyze the success rate of one method of management (dry debridement, multiple punctuate keratotomies and soft contact lens badnage) of refractory corneal epithelial erosions as an initial therapy by one clinician (a resident) over a 3-year time period.

Methods:  Canine patients diagnosed with a refractory corneal epithelial erosion with no concurrent ocular pathology noted were included in the retrospective study. Patients were treated with an initial procedure that included dry debridement, multiple punctuate keratotomies, and placement of a soft contact lens bandage. Successful treatment of the ulceration was measured by the presence of adherent epithelium with no defects present within 7 days of initial treatment and required no further follow-up. Unsuccessful outcomes were subsequently treated with repeated debridement and/or superficial keratectomies.

Results:  Greater than 80% of refractory corneal epithelial erosions responded successfully to initial management by this method.

Conclusions:  Dry debridement with multiple punctuate keratotomies and placement of a soft contact lens bandage is a satisfactory initial management tool for canines with refractory corneal epithelial erosions.

ABSTRACT NO.: 53

Refractive state of pseudophakic canine eyes and the correlation between ametropia and preoperative ultrasonic biometry

K. L. Combs*, A. Hoffman* and T. Lehenbauer†
*Eye Care for Animals, Pasadena, CA, USA; †Oklahoma State University, Stillwater, OK, USA

Purpose:  This study aims to determine the refractive state of dogs following phacoemulsification and synthetic lens implantation. Also to determine if a correlation is present between preoperative ultrasonic biometry and postoperative ametropia.

Methods:  A total of 22 dogs (44 eyes) were used in this study. Thirty-one eyes underwent phacoemulsification with placement of a +41D intraocular lens implant. Eighteen of the 31 eyes underwent bilateral surgery and 13/31 eyes underwent unilateral surgery. Preoperative ocular biometry was also performed on 26 pseudophakic eyes. Axial globe length, anterior chamber, lens, and vitreous chamber depth were measured by A-scan ultrasonic biometry. Streak retinoscopy was performed to determine the post-operative refractive state of each eye.

Results:  Mean ± SD refractive state of all pseudophakic eyes was −0.403 ± 3.62D with a range of −17 to +5.5D. Mean ± SD anterior chamber depth was 3.04 ± 0.69 mm with a range of 2.03 to 4.16 mm. Correlation between refractive state and anterior chamber depth was found to be significant (r = −0.426, P = 0.015).

Conclusions:  Eighty-seven percent of our pseudophakic study population was within ±2D of emmetropia. Among the dogs, 51.6% were myopic, 38.7% were hyperopic, and 9.7% were emmetropic. A significant negative linear correlation was present between the depth of the anterior chamber and the degree of postoperative ametropia.

ABSTRACT NO.: 54

Selenium functionalized intraocular lenses inhibit posterior capsule opacification in an ex vivo canine lens capsular bag assay

S. A. Pot*, H. L. Chandler‡, C. M. H. Colitz‡, E. Bentley*, R. R. Dubielzig†, T. S. Mosley¶, T. W. Reid§ and C. J. Murphy*
Departments of *Surgical Sciences and †Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin–Madison, Madison, WI, USA; ‡Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus, OH, USA; §Department of Ophthalmology and Visual Sciences, Texas Tech University Health Science Center, Lubbock, TX, USA; ¶Selenium Ltd., Lubbock, TX, USA

Purpose:  Selenium (Se) compounds induce apoptosis by generating superoxide radicals. The purpose of this study was to demonstrate the use of selenocystamine-coated intraocular lenses (IOLs) as a safe and effective means to reduce the formation of posterior capsule opacification (PCO) in an ex vivo canine lens capsular bag assay.

Methods:  Primary canine lens epithelial cells (LECs) and canine lens capsular bag cultures were established. Selenocystamine was covalently bound to the surface of poly (HEMA) discs. Cell viability assays were performed on LECs cultured in tissue culture medium pre-incubated with either a coated (SeIOL) or noncoated IOL. Three groups of canine lens capsules (SeIOL, control IOL, and empty) were cultured for 10 days. During the culture period the stage of PCO development was scored based on visual inspection of the capsules. On day 10 all the capsules were formalin fixed and paraffin embedded. Sections were stained with hematoxylin–eosin, Alcian blue/PAS, and Masson's trichrome stains as well as immunohistochemical markers for proliferation (PCNA), myofibroblast formation (αSMA), and apoptosis (Caspase-3). LECs adherent to the posterior lens capsule were quantified.

Results:  The viability assays showed no toxicity attributable to the Se functionalization. The central posterior capsule was free of cells underneath all of the SeIOLs, although large numbers of LECs populated the capsular periphery. Apoptotic cells were observed underneath the periphery of some of the SeIOLs. Both the PCO scores and the LEC counts of SeIOL containing capsules were significantly lower than those of the control group capsules (P ≤ 0.01 and P ≤ 0.0001, respectively).

Conclusions:  A drastic reduction of PCO formation was observed in this ex vivo model. Covalent binding of Se to a conventional foldable IOL could be a safe method to prevent population of the central posterior capsule with LECs. Supported by ACVO Vision for animals foundation resident research grant. Reid: P

ABSTRACT NO.: 55

Evaluation of variables that affect outcome of phacoemulsification in eyes of dogs: a preliminary study

N. M. Park*, P. A. Gerding*, R. E. Merideth† and D. J. Schaeffer‡
*Eye Care For Animals, Chicago, IL, USA; †Eye Care For Animals, Tucson, AZ, USA; ‡University of Illinois, Department of Veterinary Biosciences, Urbana, IL, USA

Purpose:  Monitoring incidence of risk factors for both short- (< 1 month) and long-term (≥ 1 month) complications of elective phacoemulsification in dogs may lead to better outcomes.

Methods:  Thirty-five eyes (22 dogs) were included in this prospective study. Follow-up time varied between 7 and 19 months. Variables evaluated included preexisting medical conditions, duration of cataracts prior to surgery, stage of cataract present, gonioscopic findings, phacoemulsification time, and surgery time. Statistical analysis was performed using the Fisher's exact and Kruskal–Wallis tests.

Results:  Intraoperative complications included unintentional posterior capsular tear, vitreal prolapse following posterior capsulotomy and mild ciliary hemorrhage. Time to development of glaucoma and retinal detachment ranged from 1 day to 4 months and 10 days to 6 months postoperative, respectively. Surgeons with less experience did have a higher proportion of postoperative ocular hypertension. The use of carbachol during surgery was associated with a lower 1-day postoperative intraocular pressure, but no significant relationship was noted with development of ocular hypertension or glaucoma. Retinal detachment was seen equally in both diabetics and nondiabetics as well as in lens-induced uveitis (LIU) and non-LIU eyes.

Conclusions:  This study confirmed that glaucoma and retinal detachment are the leading causes of failure following phacoemulsification in our patients and risk factors appeared to be multifactorial. Definitive causes and effects have not been substantiated and further prospective evaluations are warranted.

ABSTRACT NO.: 56

Antifungal susceptibility testing of Aspergillus species isolated from horses with keratomycosis in Southeast Pennsylvania: 10 cases (2006–2007)

K. L. Wotman, M. E. Utter and S. C. Rankin
New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA

Purpose:  This study aims to determine susceptibility of Aspergillus species cultured from horses with keratomycosis to commonly used antifungals including itraconazole, miconazole, natamycin, and voriconazole.

Methods:  An Aspergillus species was cultured from 16 out of 32 horses with fungal keratitis from 2006–2007 at the University of Pennsylvania, New Bolton Center. Fungal isolates were cultured on Sabouraud's agar and inhibitory mold agar using standard techniques and plates were incubated at 30 °C. Lactophenol cotton blue staining was used for the presumptive identification of Aspergillus. Eleven isolates were sent to the Fungus Testing Lab at University of Texas Health Science Center, San Antonio, for antifungal susceptibility testing using broth microdilution as described in the CLSI M38-A2 Approved Standard. Four different antifungal agents were tested in vitro: natamycin, itraconazole, voriconazole, and miconazole.

Results:  Ten of 11 isolates of Aspergillus were included in the study. One isolate was nonviable despite repeated attempts to subculture. Based on in vitro minimum inhibitory concentration (MIC; µg/mL), all 10 Aspergillus species were sensitive to itraconazole and voriconazole at 24 h. Eight isolates were sensitive to itraconazole, and four were sensitive to voriconazole at 48 h. None of the Aspergillus species was sensitive to natamycin (MIC range from 4 to 32 µg/mL). Two of the 10 isolates were sensitive to miconazole at 24 and 48 h.

Conclusions:  Itraconazole or voriconazole should be the topical drug of choice for treating equine fungal keratitis caused by Aspergillus species in southeastern Pennsylvania. Supported by US Department of Agriculture.

ABSTRACT NO.: 57

Ophthalmic lesions in equine neonates presenting to a referral hospital for evaluation of nonophthalmic disease

A. L. Labelle, R. E. Hamor, M. K. Zarfoss and C. B. Breaux
College of Veterinary Medicine, University of Illinois Urbana-Champaign, IL, USA

Purpose:  This study aims to investigate prevalence of ophthalmic lesions in equine neonates (< 2 weeks of age) presenting to a referral hospital for nonophthalmic disease.

Methods:  All equine neonates presenting to the Equine Medicine and Surgery service of the Veterinary Teaching Hospital < 2 weeks of age were eligible for inclusion in the study. A complete ophthalmic examination including slit lamp biomicroscopy, indirect ophthalmoscopy, Schirmer tear test, fluorescein staining and intraocular pressure measurement with a rebound tonometer was performed on each patient. A total of 29 foals were examined for the study.

Results:  Entropion was identified in 6/29 foals (21%, CI [8–40%]), corneal ulcer in 7/29 foals (24%, CI [1–44%]), anterior uveitis in 7/29 foals (24%, CI [1–44%]), cataract in 3/29 foals (1%, CI [2–23%]), and retinal hemorrhages in 3/29 foals (1%, CI [2–23%]).

Conclusions:  Consistent with previous reports, entropion and corneal ulcers were prevalent in this population of equine neonates; however, a significant number of foals were also identified with anterior uveitis. A complete ophthalmic examination is indicated in every equine neonate presenting to a referral hospital to identify the presence of ophthalmic disease.

ABSTRACT NO.: 58

In vitro and in vivo evaluation of an equine intraocular lens

R. J. McMullen Jr, J. H. Salmon, M. G. Davidson and B. C. Gilger
North Carolina State University, Raleigh, NC, USA

Purpose:  This study aims to determine refractive state and postoperative anterior chamber depth (PACD) of cadaver and live equine eyes implanted with IOLs to determine appropriate IOL power to achieve emmetropia.

Methods:  Extracapsular lens extraction and placement of a +30D IOL was performed on six enucleated equine eyes. Four live horses received a +25D IOL implant after lens extraction. Streak retinoscopy and ultrasound (pre- and postoperative globe dimensions: ACD, CLT, and axial length [AxL]) were performed on each eye before and after IOL implantation.

Results:  Preoperative mean refractive error of −0.46D (SD ± 1.03) was obtained from cadaver eyes. Preoperative globe dimensions were: ACD: 7.12 mm (SD ± 0.82), CLT: 11.32 mm (SD ± 0.81), and AxL: 40.51 mm (SD ± 1.26). Postoperative anterior chamber depth (PACD): 10.76 mm (SD ± 1.16). No IOLs were positioned posterior to the preoperative ACD +50% CLT. Implantation of a +30D IOL resulted in mean overcorrection of 2.96D (SD ± 0.84) in enucleated globes. A +25D IOL in adult horses resulted in a mean overcorrection of 3.94D (SD ± 1.18) at 30 days after surgery.

Conclusions:  Due to a more anterior PACD than estimated previously, a +30D IOL overcorrected equine cadaver eyes. A +25D IOL overcorrected four live horses. Further refractive and ultrasonographic data are needed to determine the appropriate refractive power and PACD of the IOL. Supported by ACVO-VAF Grant 2006–2007.

ABSTRACT NO.: 59

Equine tear film break-up time

C. M. Nunnery, D. E. Brooks, C. E. Plummer and K. P. Barrie
Departments of Small and Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA

Purpose:  Horses with qualitative tear film problems are commonly recognized. Tear film break-up time (TFBUT) can help to identify these animals, by detecting abnormalities in the mucin and lipid layers of the precorneal tear film (PTF). The purpose of this study was to develop a protocol for performing tear film break-up time and to establish normal values for this test in horses.

Methods:  This study included 10 thoroughbred mares and their foals. Horses with a poor Schirmer tear test (STT) and/or corneal, conjunctival or lid abnormalities were excluded from the study. Complete ophthalmic examinations were performed at least 24 h prior to testing TFBUT. This was done to avoid any irregularities in PTF due to the Schirmer tear test strip and tonometry. Animals were sedated using intravenous xylazine (AnaSed, Llyod Labortories, Shanandoah, IA, USA), detomidine (Dormosedan, Pfizer Animal Health, Exton, PA, USA) or both, and all animals received a 2% lidocaine (Lidocaine HCL, American Regent Inc., Shirley, NY, USA) auriculo-palpebral block. To perform the TFBUT, 0.1 mL of 0.5% fluorescein stain was applied to the dorsal bulbar conjunctiva. The 0.5% fluorescein solution was prepared by placing 10 fluorescein sodium strips (FUL-GLO, Alkon, Buffalo Grove, IL, USA) in 2.0 mL of eyewash (Eye Wash, Major Pharmaceuticals, Livonia, MI, USA). The lid was then manually blinked by the examiner three times to attain an even distribution of fluorescein over the cornea. After the last blinking motion the timer was started and the cornea was scanned using a Kowa SL15 with cobalt blue filter. The timer was stopped when the first darkened area, representing instability in the PTF, was observed. This was repeated three times for each eye examined. All examinations and TFBUT were performed in a closed environment. The statistical method used for this study was the one-way analysis of variance.

Results:  The average tear film break-up time for all horses was 21.8 s; in mares TFBUT was 18.7 s, and in foals was 24.9 s. The standard deviation for all three groups was 10 s. There was no statistical difference between the TFBUT of mares and that of foals (P = 0.0609).

Conclusions:  Tear film break-up time is a simple test that can be incorporated into an ophthalmic examination protocol with little additional time or supplies. This information may help in diagnosis of qualitative tear film disorders in equine patients.

ABSTRACT NO.: 60

The effect of intravenous hydromorphone, butorphanol, morphine, and buprineorphine on pupil size and intraocular pressure in normal dogs

C. G. Pirie, C. Blaze, E. Casey and S. Pizzirani
Department of Clinical Sciences, Tufts Cummings School of Veterinary Medicine, North Grafton, MA, USA

Purpose:  This study aims to determine the effects of intravenous morphine, hydromorphone, buprenorphine, or butorphanol on pupil size and intraocular pressure in normal dogs.

Methods:  A randomized, placebo-controlled, masked clinical trial using 12 healthy beagle dogs was conducted. Dogs were randomly assigned to either treatment (opioid IV) or control (0.9% saline IV) for each of four trials. A 1-week washout period was allowed between each trial. One of the four opioids was administered intravenously in each trial and pupil size and intraocular pressure were measured at baseline and immediately after injection (T0) and at the following time (minutes) after injection: T5, T10, T30, T60, T120, T180, and T240.

Results:  Pupil size was significantly smaller (P < 0.05) than control only after butorphanol and only within the first 10 min after injection. There were no significant differences in pupil size comparing control to morphine, hydromorphone, or buprenorphine. Morphine produced slight mydriasis within 1.5 h of injection but not to a significant degree. Intraocular pressure was not significantly different from control (pretreatment baseline) at any time point for any of the opioids studied.

Conclusions:  For intraocular procedures in dogs, morphine, hydromorphone, or buprenorphine can be used for systemic analgesia at the doses used in this study without causing significant miosis or changes in intraocular pressure. Butorphanol decreases pupil size only within the first 10 min of injection and does not significantly change intraocular pressure. Supported by NIH short term training grant T35 DK07635.

ABSTRACT NO.: 61

Early-onset day blindness with reduced night vision in the standard poodle

J. C. Norman* and K. Narfström†
*Eye Care for Animals, Phoenix, AZ, USA; †Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA

Purpose:  Sporadic cases of day blindness in Standard Poodles have previously been recognized. We wanted to further characterize the ophthalmic and electroretinographic (ERG) findings in the disease utilizing two affected littermates.

Methods:  Ophthalmic evaluation of five closely related standard Poodles, aged 4–12 months, was performed on two occasions, 6 months apart. Two were affected littermates, while the other dogs served as age-matched controls. Examinations included maze testing in bright fluorescent light and in low lighting conditions, followed by slit lamp biomicroscopy and indirect ophthalmoscopy. Following deep sedation using medetomidine (Domitor®, Orion, Finland, 750 µg/m2 IV), ERGs were obtained with a portable ERG unit (HMsERG, RetVetCorp Inc., Columbia, MO, USA). An automated, standardized protocol for evaluation of the process of dark adaptation and discrimination of rod and cone function was utilized.

Results:  Behavioral testing for vision demonstrated that the two affected littermates bumped into objects and had difficulties navigating in bright light while they behaved more normally in a scotopic environment. Both affected dogs had a normal dazzle response but they only menaced in dim light conditions. Pupillary light reflexes, using the Finhoff transilluminator, were slower than in the normal dogs. Funduscopically, both affected dogs demonstrated mild to moderate vascular attenuation, mild generalized tapetal discoloration, and tapetal hyperreflectivity mainly in the midperipheral fundus. Photopic ERGs were nonrecordable for both affected dogs. Markedly reduced scotopic recordings were found for one of the littermates, while for the other, these were nonrecordable at age 4 months. For the former dog, clear scotopic a- and b-waves were obtained only when using a standard flash (3 cd.s/m2) or higher intensity of light stimulation. At lower intensities, the b-wave was replaced by a late, negative response. At follow-up, funduscopic changes had progressed and ERG recordings were replaced by either negative or flat, nonrecordable responses. The dogs were functionally blind in both photopic and scotopic conditions at follow-up.

Conclusions:  The standard poodle is affected by an early-onset photoreceptor dystrophy. The disease affects the cones more severely initially, but the rods are also affected very early in life. This dystrophy is progressive and results in functional blindness within 1 year of age. In the future, we hope to present the morphologic and molecular basis of the condition. Supported by Eye Care for Animals Research Fund.

ABSTRACT NO.: 62

Relationship between rpgrip1 mutation and progressive retinal atrophy in Miniature Long-haired Dachshund population in Japan

K. Morimoto*, K. Miyadera†, K. Kato‡, S. Tamahara‡, N. Sasaki‡ and H. Ogawa§
*Mizuhodai Animal Hospital, Fujimi-shi, Japan; †Laboratory of Genetics, University of Cambridge, Cambridge, UK; ‡Veterinary Medical Center, University of Tokyo, Tokyo, Japan; §Japan Animal Referral Medical Center, Kawasaki-shi, Japan

Purpose:  In 2006, a canine retinitis pigmentosa GTP-ase regulator interacting protein 1 (RPGRIP1) mutation of cone-rod dystrophy, comparable to human Leber congenital amaurosis, was detected in Miniature Long-haired Dachshunds (MLHD) by Mellersh et al. The purpose of this study was to investigate the prevalence of RPGRIP1 gene mutation in MLHDs in Japan with or without progressive retinal atrophy (PRA).

Methods:  Whole blood samples were obtained from 232 MLHDs. All animals underwent a complete ophthalmic examination. When PRA could not be detected by indirect ophthalmoscopy, we employed electroretinography for its diagnosis. Based on these test, the MLHDs were classified into two groups: PRA group and the normal group. DNA was extracted from whole blood samples. The genotype was determined by use of polymerase chain reaction and electrophoresis. Statistical analysis were performed using a Mann–Whitney U-test and chi-squared test for independence. Statistical significance was set at P < 0.05.

Results:  Thirty-five dogs were diagnosed with PRA; 197 dogs were normal. There were no significance differences in gender and age between dogs with PRA and normal dogs. The discordance rate between genotype and phenotype was 16.2% in the normal group and 20% in the PRA group. A marked variation in the age of onset of PRA was present in this study with a range from 3 months to 10 years of age. This was different from previous studies.

Conclusion:  Although the RPGRIP1 mutation is associated with onset of PRA in MLHD in the United Kingdom, this mutation does not appear to be associated with PRA in our population of dogs. It is likely that other genes or factors are responsible for the wide range in age of onset of PRA in the MLHD in Japan.

ABSTRACT NO.: 63

Comparison of neural progenitor cells isolated from adult canine and mice retinas

A. R. R. Carvalho*, A. Dick†, D. Fondevila*, T. Peña*, P. Martinez‡ and A. Iborra‡
*Department of Animal Medicine and Surgery, Autonomous University of Barcelona, Bellaterra, Spain; †Department of Clinical Sciences, University of Bristol, Bristol, UK; ‡Institute of Biotechnology and Biomedicine, Autonomous University of Barcelona, Bellaterra, Spain

Purpose:  We have currently isolated neural progenitors cells (NPC) derived from adult dog and mice retinas to compare proliferation and expansion potential in vitro and viability following culture passages.

Methods:  Six donated retinas from three cross-breed adult dogs, were compared to 20 BALB/c mice retinas. Retinas were enzymatic digested, and cell suspension were cultured and mechanically passaged to visualize neurosphere (NS) formation, cell aggregation and measure single cells and NS size. Immunostaining with BrdU, nestin, and GFAP was performed.

Results:  NPC derived from dog and mice retinas demonstrated the same characteristics in culture. They formed free floating NS which were BrdU positive although the extent of proliferation declined after each passage. NS formation was faster in mice compared to dogs. NS from both species were nestin positive. Immunoreactivity to GFAP increased with each passage and was more abundant in cells derived from dogs. It was not possible to promote a linear expansion. There was a significant difference in cell and NS size between time in culture and between species (P < 0.05).

Conclusion:  NS formation, nestin labeling, and the proliferative capacity are indicative of the presence of residual NPC in adult canine and mice retina. The results observed here are similar to previous findings in adult human retina, suggesting that there is no ubiquitous difference between dog, mice, and human and indeed there is a conservation of retinal progenitor cell properties. That finding could open a new window to investigate and understand the biology of cell replacement in several retinal pathologies.

ABSTRACT NO.: 64

Mapping of cone photoreceptor subtypes in the canine retina

F. M. Mowat*, S. Petersen-Jones†, H. Williamson‡, D. Williams‡, R. R. Ali* and J. W. B. Bainbridge*
*Department of Molecular Therapy, UCL Institute of Ophthalmology, London, UK; †Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA; ‡Department of Veterinary Ophthalmology, University of Cambridge, Cambridge, UK

Purpose:  While it is well established that the dog retina has a large visual streak with a marked area centralis, detailed characterization of the topography of the cone photoreceptors in the canine retina has not been reported. The purpose of this study was to determine the distribution of cones and opsin subtypes in order to aid the study and treatment of retinal disease involving cone photoreceptors.

Methods:  Retinal flat-mounts from research Beagle dogs were stained with peanut agglutinin (labeling cone outer segments), and antibodies against L/M- and S-cone opsins. Retinas were imaged using fluorescence and confocal microscopy and analyzed in a grid pattern to map the density of cone subtypes across the retina. The ratio of rods and cones in areas across the retina was calculated.

Results:  A region of retina extending in a streak dorsal to the optic disc had a substantially higher proportion of cones compared to the peripheral retina. Within this streak the greatest proportion of cones relative to rods was in the region temporal to the disc. In that region L/M cones were the predominant subtype.

Conclusions:  We have identified the areas of peak cone density in a common research breed of dog. This is essential baseline information for studies that aim to characterize and treat cone photoreceptor dystrophies in the dog. Supported by Wellcome Trust Grant 074617/Z/04/Z, Medical Research Council Grant G03000341, BrAVO Travel Scholarship 2008.

ABSTRACT NO.: 65

Aav gene therapy restores day-vision in dogs with primary loss of cone function

A. M. Komáromy*, J. J. Alexander†, V. A. Chiodo‡, M. M. Garcia§, A. Kaya§, J. C. Tanaka§, C. M. Craft¶, G. M. Acland**, W. W. Hauswirth‡ , †† and G. D. Aguirre*
*Department Clinical Studies, University of Pennsylvania, Philadelphia, PA, USA; †Department Pathology, University of Florida, Gainesville, FL, USA; ‡Department Ophthalmology, University of Florida, Gainesville, FL, USA; §Department Biology, Temple University, Philadelphia, PA, USA; ¶Mary D. Allen Lab, Doheny Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; **Baker Institute, Cornell University, Ithaca, NY, USA; ††Department Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA

Purpose:  This study aims to evaluate restoration of cone function following recombinant adeno-associated virus (rAAV)-mediated gene therapy in two canine models of achromatopsia.

Methods:  rAAV of serotype 5 containing human CNGB3 cDNA was injected unilaterally into the subretinal space of dogs affected by either a null or missense mutation (D262N) of CNGB3. The dogs were between 3 weeks and 2 years old at the time of treatment. The transgene was under control of a cone-specific promoter, either a truncated human red cone opsin or a human cone arrestin promoter. Depending on the size of the dog, the total volume injected varied between 50 and 180 ìL containing between 3.73 and 16.5 × 1012 genome containing particles/mL. At least 4 weeks after treatment, cone function was evaluated behaviorally and by electroretinography under photopic conditions. CNGB3 transgene expression was measured by quantitative real-time–polymerase chain reaction (qRT-PCR).

Results:  Successful restoration of cone function was achieved in 16 dogs with either CNGB3 null or missense mutation. The robustness of the rescue was promoter-dependent but mutation-independent. While positive results were seen with all promoters, the longest version of the human red cone opsin promoter (PR2.1) led to the most robust restoration of cone function. Two treated dogs were monitored for over 24 months, and no deterioration of the rescue effect was observed. The amplitude of the rescued cone function decreased with age at injection, with the best results achieved at 3 weeks and no detectable rescue when the injection occurred beyond 1 year of age. In successfully treated eyes, expression of CNGB3 transgene mRNA was detected by qRT-PCR.

Conclusions:  Robust, long-term rescue of cone function could be achieved in two canine models of achromatopsia. The best outcome was observed when animals were treated at a young age. Our results are promising for future gene therapy in human patients with achromatopsia, or other diseases that affect cones. Supported by NIH, RPB, FFB, MVRF, McCabe Fund, The ONCE Int’l. Prize. Commercial Relationship: P (WW Hauswirth, AGTC).

ABSTRACT NO.: 66

Quantitative iridocorneal angle measurements in normal Beagle dogs using ultrasound biomicroscopy

U. M. Dietrich, L. Boozer and W. L. Weinstein
Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA, USA

Purpose:  This study aims to evaluate the iridocorneal angle opening distance and ciliary cleft in normal Beagle dogs using ultrasound biomicroscopy (UBM) and to establish reference values in this breed.

Methods:  Twenty-one male, 18-month-old Beagle underwent a complete ocular examination, including slitlamp biomicroscopy, tonometry, and indirect ophthalmoscopy. Gonioscopic examination of both eyes was performed with a Koeppe goniolens; angle width was estimated using the grading scheme by Ekesten et al. (1991). Dogs were anesthetized with i.v. (Domitor®)/Butorphanol and stay sutures were placed at the 3 and 9 o’clock position using 5-0 Vicryl. A plastic eye cup, filled with methylcellulose and saline and placed in the lid fissure, served as an external waterbath. The 50-MHz ultrasound transducer (Paradigm Ultrasound Biomicroscope™, Model P40) was immersed and both eyes were examined in 4 quadrants over the limbal region (at the 12, 6, 3, and 9 o’clock positions). Iridocorneal angle opening distance was measured with the software-integrated internal calipers as previously described by Pavlin and Foster (1995). For statistical analysis, a repeated measures model and Tukey's test were used to evaluate UBM measurements. Confidence level was at 95%.

Results:  Ophthalmic examination in both eyes was normal for all dogs. Angle widths were gonioscopically considered grade 4 in all eyes. With UBM the mean iridocorneal angle opening of all anatomical positions measured 27.5920 (± 0.9152) for the right eye and 29.8694 (± 0.9065) for the left eye. Mean degree of angle opening was 28.4532 (± 1.1183) for the 12 o’clock position, 29.4101 (± 1.1313) for the 6 o’clock position, 28.4665 (± 1.11833) for the 3 o’clock position, and 28.5930 (± 1.131) for the 9 o’clock position in all eyes. Overall, there was no significant difference between measurements in all 4 quadrants (P > 0.05). The ciliary cleft was open in all eyes.

Conclusions:  UBM is an accurate and objective method to evaluate iridocorneal angle and ciliary cleft width in dogs. Reference values were established for the normal Beagle dog. Supported by the University of Georgia Veterinary Ophthalmology Research Fund.

ABSTRACT NO.: 67

Pathological factors involved with the late onset of canine glaucoma associated with goniodysgenesis: preliminary study

S. Pizzirani*, V. Carroll†, C. Pirie*, J. Keating† and R. Dubielzig‡
Departments of *Clinical Sciences and †Biomedical Sciences, Tufts Cummings School of Veterinary Medicine, North Grafton, MA, USA; ‡Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA

Purpose:  Evaluate the pathological findings of glaucoma with goniodysgenesis and hypothesize factors contributing to late-onset glaucoma in congenitally predisposed patients.

Methods:  Eyes with only a diagnosis of glaucoma and goniodysgenesis were evaluated with standard hematoxylin–eosin microscopy. Cellular infiltrate and pigmentary dispersion were scored (0 to 3) in the iridocorneal angle, uveal and uveo-scleral trabecular meshwork, ciliary body and iris.

Results:  Eleven globes were evaluated. Four were Basset Hounds, five American Cockers, and one Siberian Husky (bilateral). Eight were spayed female (SF) and two male castrated (MC). Median age was 9.5 (3–15). Median time between onset of clinical signs and enucleation was 43 days (1–960). All eyes presented mononuclear infiltrate, pigmented cells, and pigment dispersion in the outflow pathways. Average score for cellular infiltrate and pigment distribution were 1.50 (± 0.45) and 1.52 (± 0.48) respectively, with a positive correlation coefficient (0.69). Melanophages and cellular infiltrate were mostly distributed within the trabecular meshworks. Pre-iridal fibrovascular membrane was reported in 7/10 while in 3/10 fibrocytes without capillary buds were seen on the anterior iris. All samples showed neuroepithelial epitheliopathy with cystic degeneration, loss, and hypertrophy, mostly at the pupillary portion of the iris.

Conclusions:  Correlation of inflammation and pigment in the trabecular meshworks suggests that chronic, low grade inflammation may represent a trigger for outflow obstruction and ocular hypertension in patients with goniodysgenesis. Melanin, a well-recognized autoantigen, originates from the neuroepithelium. Genetic predisposition and contact with increased lens volume with age may contribute to its release.

ABSTRACT NO.: 68

Preliminary report: effect of a novel porous implant in refractory glaucomatous dogs

S. Roberts* and C. W. Woods†
*Animal Eye Center, Loveland, CO, USA; †TR BioSurgical, LLC, Chandler, AZ, USA

Purpose:  This pilot study's purpose is to evaluate a novel implant for controlling intraocular pressure in dogs with end-stage, medically refractory glaucoma (mrG). The implant is made of a novel, proprietary silicone-based material that reduces fibrosis and augments tissue integration.

Methods:  This is an ongoing prospective, historically controlled field study in patients with mrG. Patients receiving other forms of surgery are not allowed into this study. Using a surgical approach, a portion of the implant is placed within the anterior chamber while the remaining segment resides beneath the sclera approximating the choroidal tissue. Patients are permitted to remain on postoperative topical or systemic medications.

Results (interim):  Four patients have enrolled with a total of five eyes receiving surgical implantation; one patient received bilateral implants. Four eyes have remained within the normal intraocular pressure range (data up to 3 months) and dosing frequency and amount of topical and systemic medications have been reduced. A single patient received enucleation within 1 week after implantation owing to failure of owner compliance.

Conclusions:  The surgical technique is an acceptable method with minor postoperative complications. The implant is well tolerated with minimal tissue reaction. The long-term performance of this implant represents a potentially new management option for dogs with end-stage glaucoma. Further studies are warranted to determine if the implant will also be of use in less diseased patients or as a preemptive technique in high-risk patients. Funding Sources: TR BioSurgical, LLC, P, E.

ABSTRACT NO.: 69

Diode endoscopic cyclophotocoagulation in pseudophakic and aphakic dogs with secondary glaucoma

E. A. Lutz and J. S. Sapienza
Long Island Veterinary Specialists, Plainview, NY, USA

Purpose:  This study aims to evaluate the use of a diode laser for endoscopic cyclophotocoagulation in pseudophakic and aphakic dogs with secondary glaucoma following primary cataract removal.

Methods:  Ten dogs (n = 10 eyes) with secondary glaucoma were treated with a limbal approach endoscopic cyclophotocoagulation (ECP). Preoperative and postoperative clinical courses were retrospectively reviewed. Patients received ECP when glaucoma was refractory to medical therapy (intraocular pressure [IOP] > 25 mmHg on medication).

Results:  Eight different purebred dogs and one mixed-breed dog were treated with ECP. Five were spayed females, four were neutered males, and one was an intact male. There were seven pseudophakic and three aphakic dogs. The right eye was affected in four cases, and the left eye in six cases. One dog had previously been treated with transscleral diode laser cyclophotocoagulation in the affected eye. The average laser energy delivered was 250 mW (range 200–350 mW) at a continuous duration. The average extent of ciliary process ablation was 272.5 ± 41.4 degrees (range 185–300 degrees). Two dogs also had Ex-press® shunt gonioimplants placed at the time of ECP. Postoperative observation ranged from 3 to 9 months (average 5.7 ± 1.7 months). IOP remained normotensive (< 25 mmHg) after ECP in eight dogs from 24 h postoperatively to last evaluation. Two dogs developed glaucoma that was controlled with a topical prostaglandin analogue. At last evaluation, five dogs had maintained vision, one dog had regained vision, one dog with previously equivocal vision was nonvisual, and three dogs had remained nonvisual since preoperative examination. On average, six preoperative glaucoma medications were prescribed per patient, five were used immediately postoperatively, and two topical drugs were still administered at three months postoperatively. Postoperative complications included superficial corneal ulceration (1/10) and recurrence of glaucoma (2/10).

Conclusions:  In secondary pseudophakic and aphakic canine glaucoma, ECP was associated with both IOP control and a marked decrease in prescribed postoperative glaucoma medications in 8/10 dogs, and with return or maintenance of vision in 6/10 dogs.

ABSTRACT NO.: 70

Cloning of canine myocilin DNA from Beagles with primary open angle glaucoma

E. S. Storey, V. Chouljenko and G. Kasoulas
School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA

Purpose:  This study aims to clone and sequence DNA from the blood of four Beagle dogs with primary open angle glaucoma, two Beagle dogs carrying the mutation for primary open angle glaucoma (POAG), and from tissues of one Beagle puppy from an affected to affected breeding.

Methods:  Blood was collected in purple top tubes and prepared for polymerase chain reaction (PCR). DNA samples from dog's WBC were prepared and used for all PCR that involved DNA amplification. Total RNA from ciliary body was extracted using TRI reagent and used as template for reverse transcription–PCR (RT-PCR). Oligonucleotide primers were used to amplify full size myocilin gene by RT-PCR. A total of six other primers were designed to amplify three exons of myocilin gene using dogs DNA as template. DNA products after PCR were gel purified and directly sequenced automatically.

Results:  Primers were used for successful amplification of the dog myocilin gene exon I and a PCR product spanning the respective exon III of dog myocilin gene DNA sequence. Two attempts to amplify the smallest exon II were unsuccessful. Ciliary body tissue of a puppy from affected parents yielded full size myocilin gene sequence. Only two nucleotide substitutions were present in comparison to the sequence of the dog myocilin gene deposited to GenBank. Both nucleotide substitutions were silent (C to T) at Gly 51 and (T to C) at Ala 87.

Conclusions:  No mutations in the POAG Beagle myocilin gene were detected that would be expected to induce glaucoma or result in other pathological conditions.

ABSTRACT NO.: 71

Evaluation of tonometer and intraocular pressure variability in Dutch Belted rabbits

B. C. Gilger* , † and G. R. Burleson†
*Department of Clinical Sciences, North Carolina State University, Raleigh, NC, USA; †Burleson Research Technologies Inc., Morrisville, NC, USA

Purpose:  Dutch Belted (DB) rabbits are used commonly to evaluate the effect of glaucoma drugs in preclinical testing. Because most glaucoma drugs lower normal intraocular pressure (IOP) in rabbits only 2–4 mmHg, methods of measurement of IOP need to be consistent and repeatable. The purpose of this study was to compare the IOP variability, daily IOP repeatability, and IOP dose response using two commonly used tonometers.

Methods:  Thirty-two adult male DB rabbits were acclimated for 2 weeks by daily handling, hand restraint, and topical ocular application of PBS (50 µL) OU. Study 1 consisted of measuring the IOP OU, using the tonopen XL at 8:00 am, then measuring the IOP at 0.5, 1, 2, 4, 6, and 8 h later. Study 2 was identical except using tonovet tonometer. Study 3 consisted of 6 rabbits receiving PBS and 6 rabbits receiving 50 µL of 0.5% timolol. IOP was measured OU first with the tonovet, then the tonopen, and repeated at 0.5, 1, 2, 4, 6, and 8 h later.

Results:  The tonovet tonometer provided more consistent IOP measurements (16.6–18.2 mmHg) with lower standard deviation (3.7–6.4 mmHg) than the tonopen (15.5–18.0; 4.2–6.6 mmHg) in repeat measurements of 32 normal rabbits. The tonovet was able to detect significant IOP decrease at 30 min in the timolol treatment group (n = 6), while the tonopen was not. Based on the small group data, sample size required to determine significance of 2 mmHg pressure decrease (∝ = 0.05; 80% power) using the tonovet was 8; while using the tonopen was 28.

Conclusions:  In repeat dose IOP studies in rabbits, the tonovet tonometer may provide less variability in IOP measurements and thus allow a lower sample population to detect IOP differences than using the tonopen tonometer.

ABSTRACT NO.: 72

Iris abscesses and intralenticular fungal invasion in the horse

D. E. Brooks, D. P. Taylor, C. E. Plummer, R. Quinn, M. E. Kallberg, J. F. Roberts, B. Sheppard, K. P. Barrie, A. Baker, S. E. Blackwood, C. M. Nunnery, G. Ben-Shlomo, C. Clark and A. A. Woodworth
College of Veterinary Medicine, University of Florida, Gainesville, FL, USA

Purpose:  This study aims to describe clinical and histologic findings in horses with iris abscesses.

Methods:  Retrospective medical records study. Data collected from the medical records included signalment, clinical and histologic descriptions of ocular lesions, therapy, complications, and visual outcomes.

Results:  The medical records of six horses with unilateral iris abscesses were identified. Two eyes with iris abscesses were associated with deep stromal abscesses and responded to medical therapy alone in one case, and medical therapy and corneal transplantation in the other. Iris abscesses in two eyes were quite proliferative and associated with Descemet's membrane fragmentation and intralenticular invasion due to a Cladosporium sp. and a Fusarium-type fungus respectively. Two eyes with iris abscesses had no apparent lens involvement and resolved with medical therapy. Both eyes with lens involvement resulted in enucleation. All eyes with iris abscesses had varying degrees of anterior uveitis.

Conclusions:  This is the first report of iris abscesses in the horse, and the first report of fungal invasion of the horse lens. Iris abscesses may be a precursor lesion to some deep stromal abscesses in the horse.

ABSTRACT NO.: 73

Clinical findings and outcomes of keratomycosis in 30 horses in the Mid-Atlantic United States (2006–2007)

M. E. Utter*, K. L. Wotman*, M. Armour† and J. Bagel‡
*New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA; †Red Bank Veterinary Hospital, Tinton Falls, NJ, USA; ‡College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA

Purpose:  This study aims to determine the clinical course and outcome associated with keratomycosis in horses in the Mid-Atlantic United States.

Methods:  Records of horses diagnosed with keratomycosis at New Bolton Center from November 2006 to November 2007 with positive fungal culture were retrospectively studied. Neither horses with stromal abscess nor horses with ulcerative keratitis with hyphae on cytology but negative fungal culture were included. Signalment, history, clinical findings, therapy, and outcome were recorded for included records.

Results:  Thirty horses fit both inclusion criteria (diagnosis of keratomycosis, positive corneal fungal culture). Aspergillus spp. were the most commonly cultured fungal organisms (17/30) followed by Alternaria spp. (4/30), with 1–2 cases of each of 7 other cultured organisms. Seventeen horses had positive bacterial and fungal cultures, 10 with growth of a Gram-negative species. Fifteen of 30 horses were treated surgically with a keratectomy and amnion (8) or conjunctival (7) graft. Corneal grafts were performed in conjunction with an amnion or conjunctival graft in 3 horses. Twenty-five of 30 horses were treated topically with itraconazole, and the remaining 5 with miconazole. Fifteen of 30 horses were initially treated topically with natamycin in addition to an azole. Four horses received oral itraconazole. Globe survival was 97% (29/30). All surviving globes had a positive menace response. The nonsurviving globe had been treated with a keratectomy and amnion graft but subsequently ruptured and was enucleated.

Conclusions:  Fungal keratitis is common in the Mid-Atlantic United States, and is associated with a positive outcome.

ABSTRACT NO.: 74

Changes in the equine fundus: anatomical variation or pathological change

A. Pachten and H. Gerhards
Equine Clinic, LMU Munich, Germany

Purpose:  In the last century, the purpose of horses has changed considerably. Due to this adjustment to the status of a real companion animal, the soundness of the individual horse became more important. Diseases of one or both eyes can lead to severe limitations of usage. Blindness or an impaired view compromises the horse, the rider, and uninvolved people. With regard to prepurchase examinations and the legal regulation, the state of health and its documentation have achieved a new and controversial significance. Especially the equine fundus shows a specific buildup, anatomical variations, and pathological changes that make the interpretation of diagnostic findings sometimes difficult. The objective of this paper is to present anatomical variations and selected pathological changes in regard to their clinical relevance. The outcome for vision will be discussed by means of own experience and the literature.

Methods:  Direct ophthalmoscopy was carried out on each animal followed by photography of the fundus. A Scanning Digital Ophthalmoscope® from the Wild Medtech Company was used exclusively. In some cases sedation with 0.5 mg/kg body weight xylazine or 0.02 mg/kg body weight detomidine was necessary.

Results:  The buildup of the normal equine fundus with the tapetal and nontapetal area and the optic disc is reviewed. Anatomical Variations: In lighter coat coloured animals there can be varying degrees of pigment dilution which is called partial albinism of the fundus. Affected eyes can show additionally a hypoplastic or thin tapetum associated with a red or orange reflex. Predominantly in Greys occur single circumscribed isles of pigment in the tapetal area, which are about choroidal nevis of a characteristic blue appearance. Pathological changes: Retinal detachment can be partial (e.g. secondary to uveitis) and vision is hardly affected. A complete detachment (congenital or acquired) implies always blindness; retinal hemorrhages that resolve over several days are of no functional significance; chorioretinopathies in the form of butterfly and bullethole lesions affect vision if the lesions are greater than one-fourth of the optic disc respectively when there are more than 20–30 lesions; colobomas have no apparent interference with normal vision; different types of retinopathies have varying degrees of visual deficits; different phases of optic nerve atrophy are always ending in blindness; neoplasias of the optic disc are non progressive in most cases and have no clinical relevance.

Conclusions:  To judge if a change in the equine fundus affects vision and is furthermore progressive, the veterinarian needs large experience. The more horses you look at, the better!

ABSTRACT NO.: 75

Differential gene expression of Trpm1 may cause congenital stationary night blindness and coat spotting patterns (Lp) in the Appaloosa

L. S. Sandmeyer*, R. R. Bellone†, S. A. Brooks‡, B. A. Murphy‡, S. Archer¶, E. Bailey¶, G. Forsyth§ and B. H. Grahn*
*Department of Small Animal Clinical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; †Department of Biology, University of Tampa, Tampa, FL, USA; ‡Department of Veterinary Science, University of Kentucky, Lexington, KY, USA; §Quill Lake, Saskatchewan, Canada; ¶Department of Biomedical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada

Purpose:  Congenital stationary night blindness (CSNB) in the Appaloosa horse is associated with Leopard complex coat spotting patterns which are determined by a single autosomal dominant locus, Leopard Complex (LP). Appaloosas with CSNB are homozygous (LP/LP) while heterozygous (LP/lp) and wild-type horses (lp/lp) are not affected by CSNB. The purpose was to investigate expression levels of two candidate genes for LP (namely, OCA2 and TRPM1) and three other linked loci (TJP1, MTMR10, and OTUD7A) in the retina of normal and CSNB affected Appaloosas and in the skin of LP/LP, LP/lp, and lp/lp horses.

Methods:  Horses were categorized phenotypically as LP/LP (n = 4), LP/lp (n = 4), and lp/lp (n = 6). Complete ophthalmic examination and scotopic electroretinography were performed on all horses tested. An a-wave-dominated electroretinography (‘negative ERG’) was considered diagnostic for CSNB, which was confirmed in all LP/LP horses and in none of the LP/lp or lp/lp horses. Horses were euthanized and retina and skin (pigmented and nonpigmented) were processed for RNA isolation. Quantitative real-time RT-PCR was completed on retina and skin. Gene expression was compared in retina from CSNB-affected (LP/LP) relative to unaffected (LP/lp and lp/lp) horses as well as in LP/LP, LP/lp, and lp/lp skin.

Results: TRPM1 was the only gene substantially differentially expressed in retina and skin. TRPM1 was down-regulated (> 1800-fold) in CSNB retina (LP/LP) (P = 0.001), and marginally down-regulated (3-fold) in LP/lp retina (P < 0.005) compared to lp/lp horses. TRPM1 was also down-regulated in pigmented skin (200-fold) and unpigmented skin (280-fold) of LP/LP horses (P = 0.001), and to a lesser extent in unpigmented skin (36-fold) of LP/lp horses (P = 0.001) compared to lp/lp horses.

Conclusions:  Down-regulation of TRPM1 may be responsible for CSNB and Leopard complex spotting patterns in the Appaloosa. TRP proteins are thought to have a role in controlling intracellular Ca2+ concentration; therefore, TRPM1 may be a cation channel involved in neural transmission in the retina and melanocyte proliferation, differentiation, and/or survival in skin.

ABSTRACT NO.: 76

Phacoemulsification and implantation of +14 diopter foldable intraocular lenses in five eyes of four adult horses

W. M. Townsend, S. Jacobi and J. T. Bartoe
College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA

Purpose:  The purpose of this study was to describe the surgical and visual results after phacoemulsification and implantation of +14 diopter (D) foldable intraocular lenses (IOLs) in a series of adult horses.

Methods:  Five eyes of four adult horses underwent phacoemulsification and IOL implantation with a +14 D foldable IOL (Acri.Tec). Ocular examinations were performed at 1 week, 1 month, and 6 months postoperatively. Visual status, refractive error, and anterior chamber depth were recorded 6 months postoperatively.

Results:  Six months postoperatively, four eyes of three horses remained visual. The average refractive error was 0 D (range +0.5 to −1 D). The average anterior chamber depth was 7.44 mm (range 5.73–9.70 mm). One globe of one horse was enucleated 2 months postoperatively.

Conclusions:  The refractive error of horses after phacoemulsification and implantation of a +14 D foldable intraocular lens is within 1 D of emmetropia. Postoperative complications in one horse did result in loss of the globe. However, the complications did not appear to result from placement of the intraocular lens. Supported by the Michigan State University College of Veterinary Medicine Equine Health and Performance Fund.

ABSTRACT NO.: 77

Quantitative differences in mRNA expression of toll-like receptor-2, -4, and -9 in normal equine eyes and eyes with equine recurrent uveitis

N. Y. Yi, J. H. Salmon and B. C. Gilger
Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA

Purpose:  Toll-like receptors (TLR) detect various microbial components and play an important role in the host innate immunity. This study was performed to evaluate the quantitative differences in mRNA expression of TLR-2, -4, and -9 in normal equine eyes and eyes with equine recurrent uveitis (ERU).

Methods:  Ciliary body (normal: n = 6; ERU: n = 6), iris (normal: n = 6; ERU: n = 4), choroid/retina and corneal epithelium (normal: n = 6; ERU: n = 3) of normal eyes and eyes with naturally occurring ERU were collected. Real-time PCR assay was performed to compare mRNA expression of TLR-2, -4, and -9 between normal and ERU eyes.

Results:  A three- to fourfold elevation of TLR-2 and -9 mRNA in the iris and ciliary body and a two- to sixfold elevation of TLR-2, -4, and -9 mRNA in the choroid and retina from eyes with ERU were found compared to the mRNA levels in these same tissues of normal equine eyes. In the cornea there were no remarkable differences in the expression of the TLR-2, -4, and −9 between normal and ERU eyes.

Conclusions:  This preliminary study demonstrated up-regulation of TLR-2 and -9 mRNA in the iris, ciliary body, and choroid/retina and up-regulation of TLR-4 mRNA in the choroid/retina of ERU eyes. The current data suggest the potential involvement of TLR-2, -4, and -9 in the pathogenesis of ERU. However, further study is required to determine the role of TLR-2, -4, and -9 in ERU.

ABSTRACT NO.: 78

Diode laser transscleral cyclophotocoagulation for treatment of equine glaucoma: a retrospective study of 42 eyes of 36 horses

M. J. Annear*, D. A. Wilkie† and A. J. Gemensky-Metzler†
*Department of Comparative Ophthalmology, Veterinary Medical Center, Michigan State University, East Lansing, MI, USA; †Department of Comparative Ophthalmology, College of Veterinary Medicine, Ohio State University, Columbus, OH, USA

Purpose:  This study aims to evaluate the outcome of diode laser transscleral cyclophotocoagulation (TSCP) for treatment of equine glaucoma.

Methods:  Medical records of horses undergoing TSCP at the Ohio State University (1995–2007) were reviewed. Factors evaluated included intraocular pressure (IOP), vision, medical therapy, concurrent disease, laser settings, and complications.

Results:  A total of 42 eyes of 36 horses were included. Active or prior uveitis was identified in 38/42 eyes (90%). Mean IOP at presentation was 37 ± 13 mmHg and 41/42 eyes (98%) were sighted. A mean of 2.88 Joules/treatment site (range 2.1–4.0) was delivered to a mean of 66 spots (range 41–120), for a total energy of 183 Joules/eye (range 99–375). Mean IOP 24 hours postoperatively was 30 ± 13 mmHg (23 eyes). Clinical follow-up ranged from 3–68 weeks (mean 15 weeks), and was divided into three groups, 3–5, 9–15, and 20–68 weeks. Mean IOP and number of eyes sighted at each follow-up time are as follows: at 3–5 weeks 19 ± 12 mmHg (22 eyes), 23/23 sighted; at 9–15 weeks 18 ± 10 mmHg (12 eyes), 12/13 sighted, and at 20–68 weeks 22 ± 12 mmHg (11 eyes), 11/11 sighted. IOP was significantly lower (P < 0.05) than pretreatment values at all times. Two eyes were enucleated due to poor IOP control and persistent ocular discomfort. Glaucoma therapy was discontinued in 3/19 eyes (16%) at 3–5 weeks. At 20–68 weeks, 8/8 eyes (100%) were receiving medical therapy. Complications included transient hyphema (5/42, 11%). Telephone follow-up ranged from 5–126 months (mean 49 months). Twenty-one of 22 owners contacted (95%) were satisfied with the surgery. Seventeen of 22 eyes (77%) were still receiving treatment for glaucoma or ERU, and 13/22 eyes (59%) were sighted.

Conclusions:  Diode laser TSCP is effective in controlling IOP and aids in the preservation of vision in equine glaucoma. Treatment does not result in a significant reduction in the need for medical therapy.

ABSTRACT NO.: 79

Efficacy of topical Kinostat™ for the prevention of cataracts in dogs with diabetes mellitus: a preliminary report

I. D. Bras*, T. R. Webb*, K. Ketring†, M. Wyman* ,, § and P. F. Kador‡ ,
*MedVet Medical Center for Pets, Worthington, OH, USA; †All Animal Eye Clinic, Cincinnati, OH, USA; ‡Therapeutic Vision Inc., Omaha, NE, USA; §College of Veterinary Medicine, Ohio State University, Columbus, OH, USA; ¶College of Pharmacy University of Nebraska Medical Center, Omaha, NE, USA

Purpose:  Approximately 75% of dogs with diabetes mellitus develop cataracts within 1 year of the time of diagnosis. Similar cataracts rapidly form in galactosemic dogs where they can be reduced in a dose-dependent manner with topical aldose reductase inhibitor Kinostat™. The purpose of this study was to investigate whether Kinostat™ can prevent or inhibit the progression of cataracts in naturally occurring DM in dogs.

Methods:  Forty dogs, newly diagnosed with DM and with minimal lens changes, were enrolled in a prospective, masked pilot study. Dogs were randomly assigned a coded vial containing either Kinostat or vehicle (placebo), with the contents of the vial (drug or placebo) masked from the examiner. Twenty-nine dogs received Kinostat, and 11 dogs received placebo. Owners were instructed to administer the agent OU TID for 1 year, and were instructed to record each time of administration in order to ensure compliance. Complete ophthalmic examinations were performed prior to enrolling in the study, and then at 1, 2, 3, 6, 9, and 12 months after. Digital images were taken after dilation at each time interval. Complete blood chemistries, HbA1C, and Kinostat blood levels were obtained at 1 year.

Results:  Cataract formation and progression was observed in 7/11 (64%) of the dogs receiving placebo with six dogs developing mature cataracts, and one dog developing equatorial vacuoles. Four dogs (36%) in the placebo group did not show evidence of cataract formation by the last follow-up; however, the population variance of the placebo group was not significantly different (P < 0.13). In contrast, cataract formation in the Kinostat group was significantly (P < 0.02) inhibited with 21/29 (72%) of dogs receiving Kinostat not showing evidence of cataract development by the last follow-up. Eight Kinostat-treated dogs (28%) developed cataracts; (3) incipient anterior cortical cataracts, (1) equatorial vacuoles, (4) mature cataracts. HbA1C values ranged from 8.4 to 12.3. Kinostat blood levels were undetectable 1 year after treatment.

Conclusion:  Initial results suggest that Kinostat is beneficial in arresting the onset and/or progression of cataracts in dogs with diabetes mellitus. Supported by NIH SBIR 1R43EY018013-01A1.

ABSTRACT NO.: 80

Effects of famciclovir on tear film parameters in cats experimentally infected with feline herpesvirus-1

C. C. Lim*, C. M. Reilly*, S. M. Thomasy* and D. J. Maggs†
*Veterinary Medical Teaching Hospital and †Department of Surgical and Radiological Sciences, University of California-Davis, Davis, CA, USA

Purpose:  This study aims to investigate effects of famciclovir on tear film break up time (TFBUT), Schirmer tear test (STT) values, goblet cell density (GCD), histological conjunctivitis, and clinical disease in cats undergoing primary feline herpesvirus (FHV-1) infection.

Methods:  Sixteen specific-pathogen-free cats infected with 3.2 × 107 plaque-forming units of FHV-1 were treated orally three times daily (8:00 am, and 2:00 and 8:00 pm) with lactose (n = 6) or 90 mg/kg famciclovir (n = 10) for 21 days postinoculation (DPI). Total disease score, clinical and histological evidence of conjunctivitis, GCD, TFBUT, and STT were recorded for 21 DPI.

Results:  Although total and conjunctival disease score and histological evidence of conjunctivitis increased in all cats following inoculation, total and conjunctival disease scores were significantly lower in famciclovir-than placebo-treated cats from 5–20 DPI. At 14 DPI histological score was significantly lower in famciclovir-treated (1.3) than in placebo-treated cats (2.3; P < 0.01). Within 7 DPI, TFBUT and GCD dramatically decreased from baseline and remained low for 21 DPI in both groups. However, at 21 DPI, GCD (goblet cells/50 epithelial cells) was significantly higher in famciclovir-treated (9.5) than in placebo-treated cats (0; P < 0.05). In both groups, STT values remained approximately constant and within normal limits.

Conclusions:  Famciclovir administered orally at 90 mg/kg three times daily is associated with significantly reduced clinical and histologic disease as well as faster recovery of GCD in cats undergoing primary FHV-1 infection. However, GCD remains abnormal for at least 3 weeks and concurrent mucinomimetic therapy is recommended. Grant support: Center for Companion Animal Health. Commercial interests: None.

ABSTRACT NO.: 81

Aqueous humor and serum pharmacokinetics of intravenous ampicillin and sulbactam in the dog

N. C. Whelan* and P. M. Imerman†
*Ontario Veterinary College, University of Guelph, Guelph, ON, Canada; †Veterinary Diagnostic Laboratory, Iowa State University, Ames, IA, USA

Purpose:  This study aims to test the hypothesis that a single intravenous dose of ampicillin/sulbactam (AMP/SULB) will reach and maintain a bactericidal concentration in an inflamed eye.

Methods:  Twenty Beagle/mixed-breed animals were allocated to one of four groups for ocular and serum sampling. Following general anesthesia, intraocular inflammation was created in one eye by aspirating 0.1 mL of aqueous humor. Dogs were dosed intravenously over 5 min with 20 mg/kg of AMP/SULB. A single aqueous and matching serum sample was taken at 0.5, 1, 1.5, 2, and 6 h posttreatment. Samples were analyzed by high performance liquid chromatography.

Results:  Peak aqueous humor concentrations of AMP 5.5 µg/mL and SULB 2.93 µg/mL were seen in the inflamed eye 1 h postinjection. Aqueous concentrations of both AMP and SULB decreased to 1.47 and 0.45 µg/mL, respectively, by 6 h. The measured peak serum concentration of AMP was 36.4 µg/mL at 0.5 h and declined to 3.8 µg/mL at 4 h with a slight rise to 5.25 µg/mL at 6 h. Measured peak serum SULB concentrations were 22.1 µg/mL at 0.5 h and declined to 1.5 µg/mL at 4 h with a slight rise to 2.3 µg/mL at 6 h.

Conclusions:  AMP/SULB concentrations in the anterior chamber were above the MIC breakpoints for sensitive organisms (Staphylococcus, Streptococcus) that other authors had previously cultured from anterior chambers contaminated during cataract surgery. AMP/SULB combination would be appropriate for antibiotic prophylaxis when given 30 min prior to intraocular surgery. Supported by the Ontario Veterinary College, University of Guelph, and College of Veterinary Medicine, Iowa State University.

ABSTRACT NO.: 82

Comparison of tepoxalin, carprofen, and meloxicam in reducing intraocular inflammation in the dog

M. A. Gilmour* and T. W. Lehenbauer†
Department of *Veterinary Clinical Sciences and †Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK, USA

Purpose:  This study aims to compare the effects of three oral nonsteroidal anti-inflammatory drugs, tepoxalin, carprofen, and meloxicam, in controlling aqueocentesis-induced anterior uveitis in the dog as measured by aqueous prostaglandin E2 (PGE2) levels.

Methods:  Thirty-six adult, mixed-breed dogs were divided into one control group and three treatment groups. Dogs in the control group received no medication. Dogs in the treatment groups received tepoxalin (Schering-Plough Animal Health, Summit, NJ, USA) 10 mg/kg p.o. every 24 h; carprofen (Pfizer Animal Health, Exton, PA, USA) 2.2 mg/kg p.o. every 12 h; and meloxicam (Boehringer Ingelheim Vetmedica, Inc., St. Joseph, MO, USA) 0.2 mg/kg p.o. every 24 h, on days 0 and 1. On day 1, an initial aqueocentesis was performed on both eyes of all dogs under general anesthesia followed by a second aqueocentesis on all eyes 1 h later. Aqueous samples were frozen at −80 °C and later assayed for PGE2 using an enzyme immunoassay kit.

Results:  There was a significant difference between PGE2 values in the first and second samples within the control group indicating that aqueocentesis did create uveitis. The median change in PGE2 values of the tepoxalin group was significantly lower than carprofen, meloxicam, and control groups. Median changes in PGE2 values for the meloxicam and carprofen groups were lower but not significantly different from changes in the control group.

Conclusions:  Tepoxalin appears to be more effective than oral carprofen and meloxicam in controlling prostaglandin-mediated anterior uveitis in an experimental model of canine uveitis. Tepoxalin therefore may be an appropriate choice when treating dogs with clinical anterior uveitis. Funded by Schering-Plough Animal Health, Summit, NJ 07901, USA.

ABSTRACT NO.: 83

A prospective study of the association of anemia and thrombocytopenia with ocular lesions in dogs

R. Ofri*, I. Aroch*, P. H. Kass†, Y. Bruchim* and M. Shelah-Goraly*
*Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Israel; †Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, USA

Purpose:  Anemia and thrombocytopenia are extremely common hematological abnormalities in dogs and have been listed in several veterinary textbooks as potential causes of retinal hemorrhage. However, a thorough literature search has failed to find any study on the prevalence of retinal hemorrhage in thrombocytopenic and anemic dogs. Therefore, we conducted a prospective study with the aim of documenting the prevalence and character of ocular abnormalities in anemic and thrombocytopenic dogs.

Methods:  Dogs were selected from patients received at the Hebrew University Teaching Hospital. The inclusion criteria were presence of thrombocytopenia (platelet count [Plt] < 150 × 103/mm3) and/or anemia (packed cell volume [PCV] ≤ 20%). Seventy-seven dogs met the inclusion criteria and were segregated into three study groups, in order to differentiate the findings associated with either hematological disorder. Group 1 (n = 24) included dogs presenting with both anemia and thrombocytopenia. Group 2 (n = 17) included dogs presenting with anemia. Group 3 (n = 36) included dogs presenting with thrombocytopenia. Healthy controls (n = 26) had PCV > 20% and Plt > 150 × 103/mm3. All dogs underwent a complete ophthalmic examination. Ocular lesions were recorded and graded according to severity (none, mild, severe).

Results:  The prevalence of ocular lesions in Groups 1, 2, and 3 was 42% (21% mild, 21% severe), 12% (mild lesions only), and 42% (25% mild, 17% severe), respectively. No lesions were recorded in healthy controls. Dogs with thrombocytopenia (Groups 1 and 3) had a significantly higher prevalence of ocular lesions compared to anemic (Group 2, P = 0.04) and control (P = 0.0002) dogs. There was no significant difference in prevalence of lesions between Groups 1 and 3 (P = 1.0), nor was there a difference between anemic and control dogs (P = 0.15). No correlation was found between PCV and lesion severity, but a significant correlation was found between Plt and lesion severity (P = 0.017). The correlation between thrombocytopenia and lesion prevalence, as well as the correlation between Plt and lesion severity, remained significant even after controlling for the most common systemic diagnosis (canine monocytic ehrlichiosis).

Conclusions:  Our findings show a significant association between thrombocytopenia and its severity and ocular lesions in dogs, regardless of the primary disease. However, we did not find a significant association between anemia and the prevalence and/or severity of ocular lesions.

ABSTRACT NO.: 84

In vivo effects of tetracyclines on healing of canine refractory corneal ulcers

H. L. Chandler*, I. D. Bras†, T. E. Robbin-Webb†, W. J. A. Saville*, A. J. Gemensky-Metzler* and C. M. H. Colitz‡
*Ohio State University, Columbus, OH, USA; †MedVet, Columbus, OH, USA; ‡Animal Eye Specialty Clinic, West Palm Beach, FL, USA

Purpose:  This study aims to evaluate the efficacy of tetracycline treatments on the rate of corneal re-epithelialization in canine patients with refractory ulcers.

Methods:  Sixty-six dogs with refractory ulcers were enrolled in this study. Patients underwent fluorescein staining, debridement, and grid keratotomy before being randomly assigned to one of the following treatment groups: (i) oral doxycycline and topical triple antibiotic ointment; (ii) topical Terramycin® (tetracycline) and oral cephalexin; and (iii) topical triple antibiotic ointment and oral cephalexin (placebo group). Each patient was treated for 4 weeks with the assigned drugs. Wound closure was monitored every 2 weeks using calipers and photography. The rate of wound healing, as well as clinical evidence of decreased pain were used to indicate drug effectiveness. Statistical analysis was performed using SAS software.

Results:  There were no statistically significant differences in patient age or sex between the treatment groups. Boxers were the predominant breed seen in all treatment groups. Dog treated with Terramycin had a significantly shorter healing time compared to the placebo group (P = 0.03). On average, dogs treated with doxycycline healed at a faster rate than dogs in the placebo treatment group, although this was not significant.

Conclusions:  We have previously shown in vitro, that tetracycline increases corneal epithelial cell migration through increased expression of growth factors and downstream signaling targets. This study provides rigorous clinical evidence of the effectiveness of topical tetracycline treatment in canine refractory ulcers; thus, identifying a safe, reliable, and cost-effective treatment for this disease. Supported by the AKC Canine Health Foundation.

ABSTRACT NO.: 85

Efficacy of cryotherapy for the treatment of canine limbal melanoma

H. J. Featherstone*, P. Renwick*, C. L. Heinrich* and S. Manning†
*Willows Referral Service, Solihull, West Midlands, UK; †Rutland House Veterinary Hospital, Liverpool, UK

Purpose:  This study aims to evaluate the efficacy and complication rate of lamellar resection followed by cryotherapy in the management of canine limbal melanoma.

Methods:  The clinical records of 14 dogs diagnosed with unilateral canine limbal melanoma and managed surgically with debulking by lamellar resection, cryotherapy (nitrous oxide), and an adjunctive graft procedure were reviewed from June 1998 to June 2008. The approximate size of the melanoma, variation in surgical technique, recurrence rate, short-term (less than 3 months) and long-term (more than 3 months) complications were assessed. Follow-up information was collected by patient reexamination or telephone interview.

Results:  The melanomas visibly involved 30 to 180 degrees of the limbal circumference. A double freeze-thaw cycle of cryotherapy was performed in 7/14 eyes and a triple freeze-thaw cycle in 7/14 eyes. An adjunctive conjunctival graft was performed in 13/14 eyes (free graft n = 2, posterior nictitans conjunctiva/cartilage n = 4, advancement graft n = 6, small intestinal submucosa/advancement graft n = 1) and a frozen homologous graft in 1/14 eyes. The duration of follow-up ranged from 6 months to 8.5 years with a median of 2.1 years. Recurrence was not clinically detected in any of the 14 eyes. Early complications occurred in 8/14 eyes and included anterior uveitis (7/14), corneal ulceration (5/14), marked corneal granulation at the graft margin (2/14), dyscoria (2/14), corneal lipidosis (1/14) and corneal oedema (1/14). Intraoperative globe perforation had occurred in 5/7 eyes with anterior uveitis and 2/2 eyes with dyscoria. Late complications occurred in 3/14 eyes and included corneal lipidosis which was either mild (< 2 mm in diameter, 1/14) or marked (> 1 cm in diameter, 2/14), the latter of which involved the axial cornea. The marked lipidosis only occurred following treatment of extensive limbal melanomas involving approximately 50% of the limbal circumference.

Conclusions:  Lamellar resection and cryotherapy is technically straightforward, minimally invasive, and is well tolerated by the patient. The combination of debulking by lamellar resection, cryotherapy (by two or three freeze-thaw cycles) and adjunctive graft placement is highly effective. Marked corneal lipidosis is most likely to occur when the limbal melanoma is extensive.

ABSTRACT NO.: 86

‘Stop and chop’ phacoemulsification technique for canine cataracts using a single incision and Akahoshi Phaco Prechopper

F. Maggio*, C. G. Pirie† and S. Pizzirani†
*Tufts V.E.T.S., Walpole, MA, USA; †Tufts Cumming's School of Veterinary Medicine, North Grafton, MA, USA

Purpose:  The purpose of this study is to describe the use of the Akahoshi Phaco Prechopper for nuclear fracture on canine eyes undergoing cataract extraction by phacoemulsification.

Methods:  The Akahoshi Phaco Prechopper was used in 11 patients (14 eyes) with immature and mature cataracts undergoing cataract surgery by single-incision phacoemulsification. The previously described prechop technique has been modified into a combined ‘stop and chop’ technique that allows for initial single-handed lens grooving and sculpting by phacoemulsification, followed by insertion of the prechopper to complete nuclear fracture. Previously performed hydrodissection allows for the bisected nuclear fragments to be rotated inside the capsule to obtain multiple wedge-shaped lens fragments. Routine tip-occlusion phacoemulsification and irrigation-aspiration follow.

Results:  Effective and safe nuclear fracture is obtained using this technique. Sculpting times and associated risks are reduced, and tip-occlusion phacoemulsification facilitated.

Conclusions:  When compared with the classic ‘divide and conquer’ single-incision technique, the present technique presents the advantage of using shorter ultrasonic times, as well as decreasing the risks for accidental posterior capsular damage during sculpting.

ABSTRACT NO.: 87

Canine capsular tension ring safety and complication rates in eyes with stable and unstable lenses

S. G. Stone, D. A. Wilkie and A. J. Gemensky Metzler
Department of Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus, OH, USA

Purpose:  This study aims to report complication rates postcataract surgery in canine eyes with stable and unstable lenses receiving capsular tension rings (CTR).

Methods:  For each dog with a stable lens, one eye received a CTR (Acrivet) (48 eyes) while the contralateral eye served as a control (48 eyes). Nine eyes with unstable lenses received CTRs. Routine phacoemulsification was performed in all eyes. CTRs were implanted into the capsular bag prior to IOL implantation. The CTR was placed after hydrodissection or just prior to IOL implantation. All eyes received acrylic foldable IOLs (Acri.Lyc,® Acrivet).

Results:  In the population of stable lenses, overall incidence of glaucoma (6%), intraocular hemorrhage (4%), and retinal detachment (2%) were equal between control and CTR eyes at the time of last follow-up. There was no significant difference in overall incidence of uveitis (35% vs. 38%) and fibrin (19% vs. 15%) between control and CTR eyes. Follow-up time ranged from 2 to 81 weeks (mean = 22). In eyes with unstable lenses, postoperative complications included glaucoma (2/9), intraocular hemorrhage (2/9), IOL displacement (1/9), IOL decentration (1/9), and blindness (1/9). Follow-up time ranged from 14 to 68 weeks (mean = 42).

Conclusions:  In eyes with stable lenses, CTR placement does not increase the risk of postoperative complications. Eyes with unstable lenses that received CTRs experienced complications; however, surgical technique, severity of prior lens instability, pre- or postoperative uveitis, cataract stage and ocular trauma were contributing factors in these cases. This population had lower complication rates than those described in previous reports on eyes undergoing ICLE. Supported by AKC CHF and Acrivet.

ABSTRACT NO.: 88

Spontaneous posterior lens rupture associated with rapidly progressive cataracts in nondiabetic dogs

I. Allgoewer*, C. L. Heinrich†, P. W. Renwick†, H. J. Featherstone†, S. M. Manning† and I. Hoffman‡
*Augen-Tierarztpraxis Dr Allgoewer, Berlin, Germany; †Willows Referral Service, Solihull, West Midlands, UK; ‡Tieraerztliche Praxis fuer Augenheilkunde Dr Hoffmann Nuernberg, Germany

Purpose:  This study aims to describe the clinical presentation and ultrasonographic appearance of spontaneous posterior lens capsule rupture in nondiabetic dogs with rapidly progressive cataracts and review the outcome of surgical management with phacoemulsification and vitrectomy +/– intraocular lens implantation.

Methods:  The clinical records of 31 eyes (of 25 dogs) diagnosed with spontaneous rupture of the posterior lens capsule associated with rapidly progressive cataracts were reviewed. The clinical and ultrasonographic presentation as well as the short- and long-term outcome of surgery to remove the ruptured lens by phacoemulsification and vitrectomy were assessed and complications recorded.

Results:  The Labrador Retriever breed was overrepresented with 13/25 dogs. Age of dogs at the time of presentation ranged from 4 months to 8.5 years with a mean age of 29 months. Five dogs were affected bilaterally. All eyes showed rapidly maturing cataracts with mild to severe signs of lens induced uveitis. A deepening of the anterior chamber was visible in 16/31 eyes. Ocular ultrasonography confirmed the presence of a defect of the posterior lens capsule in a central or equatorial position in 27/30 eyes with varying degrees of extrusion of cortical lens material into the vitreous. Phacoemulsification and anterior vitrectomy were carried out in all eyes and foldable acrylic lens implants were placed in four eyes. Follow-up time ranged from 0 to 84 months with a mean of 23 months. The mean time that operated eyes remained visual was 19 months. Eleven of the 30 eyes were blind at the time of their last follow-up. The most common cause for vision loss was retinal detachment (10/11 eyes) with subsequent glaucoma (5/11) also frequently seen.

Conclusions:  Rapidly maturing cataracts in eyes with lens induced uveitis, specifically in the Labrador Retriever, can be associated with spontaneous rupture of the posterior lens capsule and extrusion of lens material into the vitreous. The presence of a deep anterior chamber can be a significant clinical indicator of a posterior lens rupture. Ocular ultrasonography is a valuable tool to confirm the presence of a spontaneous posterior lens rupture and allows surgical planning. Rapid surgical intervention can be successful in maintaining vision in eyes affected with posterior lens rupture in nondiabetic dogs but retinal detachment and secondary glaucoma are common complications.

ABSTRACT NO.: 89

Phacoemulsification surgery for juvenile-onset feline cataracts: a retrospective review

G. L. Lynch*, D. Esson† and P. Evans*
*Eye Care for Animals at The LifeCentre, Leesburg, VA, USA; †Eye Care for Animals, Tustin, CA, USA

Purpose:  This study aims to report the short-term outcomes of phacoemulsification in domestic cats with juvenile-onset cataracts.

Methods:  A medical records search of a large multifacility private veterinary ophthalmology referral group was performed to retrospectively identify cats with juvenile-onset cataracts that had undergone phacoemulsification cataract extraction surgery.

Results:  Ten cats having undergone phacoemulsification cataract surgery over a 4 year period were identified. All 10 had bilateral cataracts and underwent bilateral surgery. Eight of 10 cats (14/20 eyes) received artificial intraocular lenses. Multifocal retinal lesions were identified postoperatively in 7/10 cats (12/20 eyes) and cerebeller hypoplasia identified preoperatively in 2/10 cats. Postoperative ocular hypertension (IOP > 25 mmHg) was a common early complication (7/10 cats, 10/20 eyes), and immediate postoperative corneal ulceration was seen less commonly (2/10 cats, 3/20 eyes). Lens capsular fibrosis and/or lens regrowth was a commonly reported long-term complication (6/10 cats, 11/20 eyes). All eyes were sighted and normotensive at final follow-up examination (mean 16.25 months).

Conclusions:  Phacoemulsification cataract extraction can be successfully performed on domestic cats with juvenile-onset cataracts. Significant complications are similar to those reported in dogs and include postoperative ocular hypertension, corneal ulceration, and lens capsular fibrosis.

ABSTRACT NO.: 90

Retinectomy: indications for, and long-term outcome in four dogs

B. H. Grahn*, J. Wolfer† and L. S. Sandmeyer*
*Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; †Islington Animal Clinic, Toronto, Ontario, Canada

Purpose:  The objective of this study was to evaluate retinectomy in dogs with chronic retinal detachment (nonattachment), as a surgical method of preventing the clinical manifestations of pre-iridal and intravitreal fibrovascular membranes, and to document complications in dogs eyes.

Methods:  We diagnosed complete rhegmatogenous retinal detachments in four dogs two of which had retinal dysplasia and perhaps nonattachment and two with acquired rhegmatogenous retinal detachments. We completed pars plana vitrectomies and retinectomies in these dogs where dysplasia and chronic retinal degeneration precluded reattachment. Each dog was reexamined for a maximum of 2 years by an ophthalmologist and the intraocular pressures and Schirmer tear tests, and ocular examinations with a biomicroscope and an indirect ophthalmoscope were completed.

Results:  Three of four dogs remain comfortable with a blind aesthetic eye postsurgically at a maximum of 24 months. One eye in one dog had marked hyphema and pre-iridal and intravitreous fibrovascular membranes preretinectomy. The hyphema persisted and worsened postretinectomy and this globe was eviscerated and an intrascleral implant was placed. Light microscopic examination of the eviscerated sample confirmed a moderate preiridal fibrovascular membrane.

Conclusions:  Retinectomy may be a viable surgical therapy to maintain an aesthetic blind globe and it may reduce the development of intraocular fibrovascular membranes, which often lead to uveitis and nonresponsive secondary glaucoma.

ABSTRACT NO.: 91

Retrospective evaluation of diode endolaser usage for retinopexy in canine patients: 16 cases

T. R. Webb*, I. D. Bras* and C. Griffiths†
*MedVet Medical Center for Pets, Worthington, OH, USA; †Twin Maples Veterinary Hospital, West Carrollton, OH, USA

Purpose:  The purpose of this study was to evaluate the use of a diode endolaser for retinopexy in canine patients.

Methods:  Fourteen eyes had partial retinal detachment, and two eyes underwent prophylactic retinopexy. Patient ages ranged from 3 to 9 years. Etiologies for the retinal detachments included previous cataract surgery (n = 3), ICLE (n = 1), and vitreal dysplasia (n = 1). In nine cases, the retinal detachment was discovered on ocular ultrasound during preoperative screening for cataract surgery, and in these cases, after routine phacoemulsification, a posterior capsullotomy was performed to gain access to the retina for retinopexy prior to intraocular lens placement. Other approaches included limbal with peripheral capsullotomy (n = 5), and pars plana sclerotomy (n = 2). A curved or a straight endolaser probe was utilized to create a double row of retinal burns with an average energy of 0.3 watt (range 0.05–1 watt).

Results:  All patients were comfortable postoperative, and by 2 weeks, large chorioretinal scars visible. Retinopexy was considered successful in preventing further retinal detachment in 11 cases (84.6%) at the time of last follow-up (range 1–35 months). The two prophylactic retinopexy cases did not have evidence of retinal detachment at the time of last follow-up (2 and 21 months). Two cases (15%) had progression of retinal detachment postoperative. All of the patients were sighted in the immediate postoperative period. Thirteen of the 16 (81%) cases were sighted at the time of last follow-up. Two cases were blind due to progression of the retinal detachment, and one case was blind due to glaucoma.

Conclusion:  Diode endolaser retinopexy can be used successfully in canine patients. The advantage of its utilization is that it combines the diode laser with direct visualization of the retina and light through a single probe. Given the large spot size gained with the close proximity to the retina, large chorioretinal scars result, which may improve the long-term success rate of this procedure compared to the transpupillary approach. Patients with partial retinal detachments found on screening for cataract surgery can undergo phacoemulsification and retinopexy to restore, and attempt to preserve vision postoperatively, with very little additional equipment and intraoperative time.

ABSTRACT NO.: 92

Application of a fluorescence assay to determine the stability of verteporfin in Domoso® and sterile water over time

E. A. Giuliano*, J. L. Whetstine† and S. A. Tucker†
*Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA; †Department of Chemistry, College of Arts and Science, University of Missouri, Columbia, MO, USA

Purpose:  This study aims to serially evaluate verteporfin (Visudyne®, Parkedale Pharmaceuticals, Priority Health Care Distribution, Orlando, FL, USA) fluorescence using two solvents and two reconstitution methods as an indirect means of determining drug activity and stability over time.

Methods:  Visudyne solutions were reconstituted daily (RD) in both sterile water and Domoso® (Fort Dodge Animal Health, Fort Dodge, IA, USA) at 0.2 mg/mL, respectively, using Visudyne powdered cake from a vial opened on study day 1 (experiment 1). Stock solutions (SS) of Visudyne in sterile water and Domoso at 0.2 mg/mL, respectively, were made from powdered cake on day 1. Aliquots from original initial SS were then tested at each measured time point (experiment 2). Neat solvents served as blank controls.

Results:  Visudyne fluorescence did not significantly decline over the 60-day study period. Results were independent of solvent type and reconstitution method. Significantly less variability in fluorescence was noted with the SS method compared with the RD method of drug reconstitution.

Conclusions:  After reconstituting a vial of Visudyne in sterile water per manufacturer recommendations it may be possible to keep it refrigerated in the dark for use within 2 months and still have adequate drug activity. Further in vivo studies are necessary to determine if tumor regression rates are similar with aged versus newly reconstituted drug for local PDT. These results are relevant to further establish the economic feasibility of local PDT as a treatment for equine periocular tumors. Supported by a Clinician Scientist Research Award from MU College of Veterinary Medicine and Department of Chemistry.

ABSTRACT NO.: 93

Effects of a meibomian glands secretion on lacrimal behavior

A. Saito, Y. Umeda, S. Wakaiki and Y. Ito
Triangle Animal Eye Clinic, Tokyo, Japan

Purpose:  We reported about two canine cases with epiphora diagnosed as meibomian glands dysfunction in the last meeting. Therefore, we investigated effect of meibomian glands secretion on tears dynamics of meibomian glands dysfunction in canine.

Materials and methods:  Following observation was carried out for Shih Tzu (1 year old, male) diagnosed as meibomian glands dysfunction. The lacrimal behavior was recorded for 1 min after having instilled a fluorescein staining solution of 2 µL with slit lamp microscope. After a rest of 10 min, a meibomian glands secretion was extruded by pressing lower eyelid margin, and the lacrimal behavior was recorded by an again equal method subsequently. Blinking, lacrimal motion, and shape of lacrimal lake were observed using a recorded movie of lacrimal behavior before and after a meibomian glands secretion. In addition, the lacrimal behavior before and after artificial tear ophthalmic ointment microdose instillation was observed in another Shih Tzu (1 year old, male) diagnosed as meibomian glands dysfunction.

Results:  Many imperfect blinks and slight motion of tears of a conjunctival sac were observed before meibomian glands secretion. In addition, abnormal tear meniscus with convex shape was observed at eyelid margin. After the treatment, many complete blinks and adequate diffusion of tear on ocular surface were observed, and the normal tear meniscus with the concave form was observed around lower eyelid margin and a cornea. In addition, the case of artificial tear instillation, lacrimal diffusion was allowed after artificial tear instillation, and formation of tear meniscus was observed.

Conclusions:  After a meibomian glands secretion, it is thought that the lacrimal behavior was improved for reduction of lacrimal surface tension and frictional reduction of eyelid margin by lacrimal lipid component. In the case of meibomian glands dysfunction on canine, it was supposed that epiphora and a slight disorder in ocular surface were provided by abnormality of a blink and lacrimal diffusion and tear meniscus. In addition, it was recognized that artificial tears ophthalmic ointment was substituted for lipid layer component.

ABSTRACT NO.: 94

Experimental reactivation of latent canine herpesvirus-1 and induction of recurrent ocular disease in adult dogs

C. Ledbetter*, S. G. Kim†, E. J. Dubovi†, A. L. Wang* and R. C. Bicalho†
Departments of *Clinical Sciences and †Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA

Purpose:  This study aims to determine if systemic administration of an immunosuppressive dosage of prednisolone to adult dogs latently infected with canine herpesvirus-1 (CHV-1) results in viral reactivation and to characterize the recurrent ocular disease, viral shedding, and serologic response.

Methods:  Ten specific-pathogen free adult Beagles (8 with experimentally induced CHV-1 latent infection and 2 uninfected dogs) were divided into the following groups: group 1, latently infected and receiving prednisolone (n = 6 dogs); group 2, latently infected and not receiving prednisolone (n = 2 dogs); and group 3, not latently infected and receiving prednisolone (n = 2 dogs). Dogs in groups 1 and 3 received prednisolone (3.0 mg/kg p.o. every 24 h) for 7 days beginning on study day 1. Conjunctival, buffy coat, and serum samples for real-time quantitative CHV-1 polymerase chain reaction (PCR) and CHV-1 serum neutralization (SN) titers were collected at regular intervals for 42 days, and general physical and ophthalmologic examinations performed.

Results:  Three dogs (50%) from group 1 developed bilateral ocular disease recrudescence (i.e., mild-to-moderate conjunctivitis) and viral shedding (mean viral titer 1.8 × 105/106 cells) between study days 5 and 20. Fourfold elevations in CHV-1 SN titers were detected in all 6 dogs (100%) from group 1 by study day 14. All buffy coat PCR assays were negative. Clinically detectable systemic disease was not observed in any dog. Dogs in control groups 2 and 3 did not develop ocular disease, CHV-1 SN titer elevations, or ocular viral shedding.

Conclusions:  The results of this study demonstrate a high frequency of viral reactivation following administration of an immunosuppressive dosage of systemic prednisolone to adult dogs latently infected with CHV-1 subsequent to primary ocular infection. Reactivation is associated with transient ocular disease recrudescence, viral shedding, and CHV-1 SN titer elevations.

ABSTRACT NO.: 95

Severe ocular signs and histopathologic findings in Watanabe heritable hyperlipidemic rabbits fed a high-cholesterol diet

S. G. Stone*, L. Gallaugher†, L. M. Wancket‡ and D. A. Wilkie*
*Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus, OH, USA; †Laboratory Animal Resources, Ohio State University, Columbus, OH, USA; ‡Department of Veterinary Biosciences, College of Veterinary Medicine, Ohio State University, Columbus, OH, USA

Purpose:  The purpose of this study is to describe ophthalmic examination and histopathologic findings in a population of 8–12 month old Watanabe heritable hyperlipidemic (WHHL) rabbits fed a high-cholesterol diet.

Methods:  After 1 month on a 0.5% cholesterol diet, 14 WHHL rabbits were divided into three groups: a control group (four rabbits) and two groups (five rabbits each group) on separate atherosclerotic plaque-reducing drugs (seasmol or lipoic acid). Serum cholesterol and triglycerides were monitored prior to the high-fat diet, prior to treatment, and posttreatment. Rabbits received regular ophthalmic and physical examinations.

Results:  After 8 weeks on the diet, ocular lesions consisted of lipid keratopathy and conjunctival hyperemia. Serum cholesterol and triglyceride levels averaged 1585 mg/dL and 320 mg/dL respectively. Within 3 months on the diet, lipid keratopathy (14), panuveitis (14), retinal detachment (6), lipid retinal infiltrate (6), scleral xanthomas (2), and buphthalmos (3) were noted. Histopathology findings included: severe lipogranulomatous choroiditis characterized by cholesterol clefting and epithelioid lipid-laden macrophages, retinal detachments, retinal degeneration, and cataracts. Gross sectioning of the eye revealed highly viscous aqueous humor with suspended lipid aggregates.

Conclusions:  While lipid keratopathy and ocular cholesterol clefting are reported in WHHL rabbits, this severity of scleral xanthomas, lipogranulomatous choroiditis and retinal detachment have not been reported in correlation with a high-cholesterol diet.

ABSTRACT NO.: 96

Antibody-mediated retinopathy: new mechanisms and treatment strategies

S. D. Grozdanic, H. Kecova, M. M. Harper, A. E. Boll and L. M. Eggers
Department of Veterinary Clinical Sciences, Iowa State University, Ames, IA, USA

Purpose:  This study aims to characterize the molecular nature of spontaneous retinopathies (sudden acquired retinal degeneration syndrome [SARDS] and immune-mediated retinitis [IMR]) in dogs and determine therapeutic effect of intravenous immunoglobulins (IVIg) and systemic steroids on restoration of different visual parameters.

Methods:  Twelve eyes from eight SARDS dogs and four eyes of two IMR dogs were analyzed using microarray analysis and immunohistochemistry for presence of immune cells and complement expression. Seven additional dogs diagnosed with SARDS were examined using pupil light reflex analysis, photopic blink reflex response, electroretinography, and visual behavior testing before and after treatment with IVIg and/or steroid therapy. Optical coherence tomography was performed to evaluate retinal thickness. Western blot and enzyme-linked immunosorbent assay analyses were performed to assess presence of serum retinal auto-antibodies in 10 patients samples and four healthy control dog samples. Necropsy and histology analysis was performed on five donor bodies (three SARDS and two IMR patients).

Results:  Molecular analysis of SARDS retinas showed intraretinal presence of immunoglobulin rich plasma cells in all stages of disease. Intraretinal plasma cells could not be detected in IMR retinas and SARDS retinas which received previous IVIg treatment. Microarray analysis of SARDS retinal tissue showed significant up-regulation of genes responsible for immunoglobulin synthesis (6–147-fold increase). Complement genes were significantly up-regulated in SARDS eyes (3–10-fold increase), which was also confirmed by immunohistochemistry. Complement protein expression was decreased in IVIg-treated SARDS eyes. All IMR patients had presence of retinal auto-antibodies in the serum. An antibody-targeting 20-kDa protein was most frequent autoantibody detected in the serum of clinical patients. Same auto-antibody could not be detected in any of control canine serum samples. Treatment with high dose of systemic steroids and doxycyline and/or IVIg resulted in recovery of visual navigation behavior and/or rod-cone mediated pupil light reflex responses in majority of treated SARDS and IMR patients. Histopathology analysis of donor cadavers revealed predominant damage of the retinal structure. All evaluated cadavers had presence of membranous glomerulonephritis.

Conclusions:  SARDS and IMR are spontaneously occurring antibody-mediated retinopathies in canine patients. These syndromes are at least partially responsive to the systemic steroid/doxycyline and IVIg therapy. Careful screening of kidney function in SARDS and IMR patients is recommended due to observed kidney changes in all evaluated organ donor samples. Support: Veterans Administration, Department of Defense, Fight for Sight, Iowa State University Biotechnology Fund.

ABSTRACT NO.: 97

Feline orbital pseudotumor: a morphologic review of 14 cases

R. R. Dubielzig, C. M. Bell and C. S. Schobert
Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA

Purpose:  Feline orbital pseudotumor (FOP) is a debilitating disease affecting the eyes and adjacent tissues in cats. Morphologically, there is an insidious infiltrate of spindle cells, collagen deposition, and perivascular round cells in the orbit, lids, skin, and soft tissues of the oral cavity leading to entrapment and loss of function of the moving tissues of the lids and orbit. Controversy exists regarding the nomenclature because the disease had features of both neoplasia and chronic inflammation.

Methods:  Fourteen cases submitted to our laboratory were reexamined.The signalment information and clinical features of the disease were obtained from the submission request. The morphologic features were recorded on review of the slide material.

Results:  The ages ranged from 4 to 16 years averaging 11 years. All cats had a typical clinical history. Histologically, all cases had the classical findings of FOP. In this series, however, we have catalogued several changes not reported before. These include an insidious increase in spindle cells in the dermis and the substantia propria of the conjunctiva, and occasionally the iris. This change in the skin and conjunctiva was seen in every case in which the appropriate tissue was sampled. Qualitatively, this subtle proliferation is not typical of inflammatory disease and suggests that FOP is more consistent with neoplasia. Overt spindle cell sarcoma was seen in the decalcified orbital tissue from one case that progressed to euthanasia.

Conclusions:  We suggest that the disease be renamed Feline Restrictive Orbital Sarcoma to reflect what we believe is the neoplastic nature of the condition.

ABSTRACT NO.: 98

Immunohistochemical analysis of canine and feline uveal melanomas

M. C. Acevedo*, C. M. H. Colitz†‡, C. A. Barden‡, K. M. Newkirk‡ , §, D. F. Kusewitt‡, R. R. Dubielzig¶ and H. L. Chandler‡
*Florida Veterinary Specialists, Tampa, FL, USA; †Animal Eye Specialty Clinic, Miami, FL, USA; ‡Ohio State University, Columbus, OH, USA; §University of Tennessee, Knoxville, TN, USA; ¶University of Wisconsin, Madison, WI, USA

Purpose:  Uveal melanoma is the most common primary intraocular neoplasm affecting cats and dogs. Unlike cutaneous melanomas, very little is known about the molecular pathogenesis of uveal melanoma. Although melanoma can be very destructive to the eye in the dog, the risk of metastasis is rare. Feline melanomas progress at a faster rate and are generally considered more invasive and malignant. Due to the link between uveal melanomas and decreased survival, it is important that the underlying mechanisms of its oncogenesis and metastasis be studied. The purpose of this study was to determine differences in the underlying mechanisms of uveal melanoma between cats and dogs.

Methods:  Formalin-fixed paraffin-embedded samples of canine and feline uveal melanomas were examined for the expression of p53, p21, p16, cyclin D, pAkt, Hsp90, and telomerase using immunohistochemistry. Appropriate age-matched, normal feline and canine eyes were used to establish baseline expression of all antibodies. The stained samples were graded for staining intensity and distribution. Data was statistically analyzed using chi-squared test.

Results:  There were no significant differences in staining patterns between canine and feline samples for p53, p21, or pAkt. However, feline melanoma samples consistently scored higher in staining intensity compared to the canine melanomas. Melanomas originating from cats had significantly higher staining scores for cyclin D, telomerase, and Hsp90 compared to canine melanomas.

Conclusions:  In the tumors examined, the feline melanomas had staining patterns suggesting increased dysregulation of the cell cycle and telomerase expression compared to the canine melanomas. The observed increased expression of cyclin D in feline melanomas supports published data indicating that increased metastasis and poor prognosis are associated with cyclin D overexpression. In addition, Hsp90 was strongly expressed in feline melanomas, which have a tendency to be more malignant. Hsp90 may have a stabilizing effect on the proliferating cells through telomerase regulation; thus, promoting tumor progression. Telomerase overexpression in feline melanomas could be an underlying mechanism for the aggressive behavior of these tumors.

ABSTRACT NO.: 99

Primary intraocular osteosarcoma and chondrosarcoma in dogs

P. Mundy and R. R. Dubielzig
Department of Pathobiological Science, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA

Purpose:  Extraskeletal osteosarcoma and chondrosarcoma are relatively uncommon in dogs, intraocular location is rare. We report four cases of extraskeletal ocular osteosarcoma and three cases of extraskeletal ocular chondrosarcoma in dogs.

Methods:  A search of the database at the Comparative Ocular Pathology Laboratory of Wisconsin revealed that out of 6000 ocular neoplasms, four cases were primary osteosarcomas and three cases were primary chondrosarcomas. The signalment information and clinical features were obtained from the submission requests. The morphological features were obtained on review of the slide material, with follow-up to determine that there was no concurrent skeletal osteosarcoma or chondrosarcoma.

Results:  Osteosarcoma: the ages raged from 8 years to 15 years, averaging 11 years. Three of the cases were unilateral and one of the cases bilateral. Two dogs were Golden Retrievers, one a Rottweiler, and one a Collie. All dogs had a clinical history of chronic glaucoma. Histologically, all cases had a carpeting of mesenchymal cells on the anterior iris with neoplastic osteoid matrix, in one of the cases the entire globe was effaced by the neoplasm. Chondrosarcoma: the ages raged from 10 to 15 years, with an average age of 11 years. The dog breeds were a Chihuahua cross, a Cocker Spaniel, and a Maltese Terrier. All the cases were unilateral with the neoplasm filling at least one chamber of the eye. Histologically, a well-differentiated cartilaginous matrix interspaced the neoplastic chondrocytes.

Conclusion:  To our knowledge this is the first report of extraskeletal chondrosarcoma in dogs. Extraskeletal ocular chondrosarcoma and osteosarcoma should be considered as a differential for primary ocular neoplasm only if no concurrent skeletal neoplasia is detected.

ABSTRACT NO.: 100

Association between papillomaviruses and the development of canine ocular squamous papillomas

A. S. Klemas*, R. R. Dubielzig† and H. L. Chandler*
*College of Optometry, Ohio State University, Columbus, OH, USA; †School of Veterinary Medicine, University of Wisconsin–Madison, Madison, WI, USA,

Purpose:  Canine ocular squamous papillomas are benign tumors of the cornea and conjunctiva. A correlation between human papillomaviruses (PV) and squamous metaplasia and neoplasia has previously been established. Canine oral PV has also been isolated as a potential cause of papillomas of the oral cavity. Currently, the biological properties of canine PV, as well as the etiology of canine ocular squamous papillomas, are unknown. This study aims to identify the presence of PV in benign squamous papillomas (BSP), reactive squamous papillomas (RSP), and squamous cell carcinomas (SCC). We also speculate that PV may play a role in squamous metaplasia. Markers of malignant transformation involved in apoptosis and proliferation, specifically p53, PCNA, cyclin D, telomerase, p16, and pAkt were also examined.

Methods:  Clinical samples of paraffin-embedded BSP, RSP, SCC, and suspected viral papillomas were used. All samples were analyzed using polymerase chain reaction (PCR); first to determine the quality of DNA present by examining GAPDH expression, then to identify PV expression using broad range PV primers. Routine immunohistochemistry was then used to localize p53, PCNA, cyclin D, telomerase, p16, and pAkt.

Results:  PCR results demonstrated a lack of PV expression in all sample groups. Furthermore, the DNA present in the tumors used was determined to be of poor quality. There was variable expression of p53, telomerase, p16, and pAkt among the samples examined. There was no expression of cyclin D, yet strong expression of PCNA in all samples.

Conclusions:  No correlation between the presence of PV and squamous metaplasia could be determined. The use of archival tissue to identify the presence of PV in squamous ocular papillomas presents a challenge due to the small sample size and variability in fixation, resulting in poor DNA yield and quality. Any progression from BSP to RSP and potentially to SCC is unrelated to markers previously shown to be associated with malignant transformation in papillomas originating in other tissues. Although not examined in this study, the authors speculate that inflammatory cytokines may be involved in promoting papilloma progression, and further investigations are warranted. An alternate method of identifying the presence of PV in squamous ocular papillomas includes the use of fresh tissue rather than archival tissue, which may produce a higher DNA yield and quality.

ABSTRACT NO.: 101

Corneal squamous cell carcinoma in dogs with a history of chronic keratitis

R. R. Dubielzig, C. S. Schobert and J. Dreyfus
School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA

Purpose:  Corneal squamous cell carcinoma (SCC) is a rare tumor in dogs. The COPLOW has seen a recent increase in primary SCC in the axial cornea. We report here on 25 cases.

Methods:  Twenty-five cases of primary axial corneal SCC were selected from the COPLOW collection which includes more that 6000 neoplastic specimens. The submission request and phone or mail contact with the referring veterinary ophthalmologist was used to obtain further details about each case such as previous history and subsequent outcomes,

Results:  The number of canine corneal SCC has risen in the past several years from 1 case per year from 1998 to 2004, jumping to 6 cases in 2005, 8 cases in 2006, and 7 cases in 2007. Brachycephalic breeds are overrepresented. The breed distribution included 8 Pugs, 5 Bulldog, 2 Boxers, 2 Greyhound, 2 Shi Tzu, 2 Border Collie, 2 Pekinese, 1 Bassett, 1 Chow, 1 Cocker, and 1 Cavalier King Charles Spaniel. No correlation to sex was found. Out of the 25 cases, 21 showed signs of chronic keratitis prior to developing SCC. In the remaining 4 cases the prior corneal history was unknown. Within the group of 25, 10 cases had been treated with cyclosporine alone, 4 with tacrolimus alone, 5 with both cyclosporine and tacrolimus, and 6 treated with other drugs or unknown. Follow-up information was obtained from 23 cases with a follow-up interval of between 5 days and 31 months (mean: 7.9 months). Three dogs had died for reasons unrelated to the ocular disease. One dog had recurrent disease extending deeply into the cornea.

Conclusions:  Brachyc ephalic dogs with a background of chronic keratitis that are treated with nonsteroidal anti-inflammatory drugs are at risk to develop axial corneal SCC. The increase in annual cases of SCC suggests that this phenomenon is a developing problem.

ABSTRACT NO.: 102

Differences in pigment distribution within the ciliary body of blue-eyed and brown-eyed dogs

K. N. Newkirk*, D. K. Haines*, S. T. Calvarese†, D. W. Esson† and H. L. Chandler‡
*Department of Pathobiology, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA; †Eye Care for Animals and ‡College of Optometry, Ohio State University, Columbus, OH, USA

Purpose:  Surgical management of canine glaucoma typically includes destruction of the ciliary body, with the intent of reducing aqueous humor production. This is commonly achieved using diode laser photocoagulation. Diode laser energy is preferentially absorbed by melanin containing tissues in the ciliary body. The purpose of the present study is to determine if there are differences in the amount of melanin in the ciliary body of blue-eyed and brown-eyed dogs and, therefore, their response to laser photocoagulation.

Methods:  Globes were collected from recently euthanized dogs at area humane societies. For histologic evaluation, eyes were fixed whole in 10% neutral buffered formalin and then processed routinely. Pigment distribution was evaluated by standard light microscopy. High resolution images of the ciliary processes (pars plicata) were digitally analyzed to determine the proportion of pigmented and nonpigmented tissue. For further quantitative determination of melanin content, samples of the ciliary processes were removed from fresh eyes, weighed and digested in 1 M KOH. The amount of melanin was then measured using a spectrophotometer at an absorbance of 420 nm.

Results:  By standard light microscopy there is a large amount of pigment present between the smooth muscle bundles at the base of the ciliary body of brown-eyed dogs; this pigment is completely absent in blue-eyed dogs. There was, however, no detectable difference in the amount of melanin in the ciliary processes of blue-eyed and brown-eyed dogs by image analysis or by spectrophotometry.

Conclusions:  Although there is no difference in the amount of pigment in the ciliary processes of blue-eyed versus brown-eyed dogs, there is a dense collection of pigment at the base of the ciliary body of brown-eyed dogs that is not present in blue-eyed dogs. This difference in the distribution of pigment within the ciliary body pigment of brown-eyed and blue-eyed dogs may have implications for the successful surgical management of the canine glaucomas.

ABSTRACT NO.: 103

Histopathological study of the causes for failure of intrascleral prosthesis in dogs and cats

C. Naranjo and R. R. Dubielzig
School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA

Purpose:  Evisceration is a common surgical procedure among veterinary ophthalmologists, but short- and long-term postoperative complications can lead to failure of the procedure, necessitating removal of the scleral shell. The purpose of this study is to evaluate the histopathological findings in scleral shells submitted to an ocular pathology service to determine which are the common causes leading to failure of the intraocular prosthesis.

Methods:  The database of the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) was searched for samples of scleral shells with intraocular prosthesis. The diagnoses and cause of the failure were reviewed to classify them into the following categories: neoplasia, severe corneal abnormalities (including corneal ulceration and perforation, incision dehiscence and epithelial downgrowth) and other causes. The database was also searched for evisceration samples diagnosed with any type of neoplasia. The same procedure was performed for dogs and cats.

Results:  One thousand five hundred and five eviscerations in dogs and 78 eviscerations in cats were found in the COPLOW database, of which 125 in dogs (8.3%) and 16 in cats (20.51%) received a diagnosis of neoplasia. There were 59 scleral shells from dogs, with the following distribution of diagnoses: 25 cases (42.37%) had recurrence of a tumor within the scleral shell, 25 cases (42.37%) had some type of severe corneal problem, including 12 with epithelial downgrowth, 4 cases (6.77%) had inflammation within the scleral shell independent of corneal disease, 3 cases (5.08%) were prophylactically enucleated after the diagnosis on the evisceration sample came back as neoplasia, 1 case (1.7%) had extensive hemorrhage within the shell, and 1 case (1.7%) had no histopathological lesions. For cats, 11 scleral shells were received, of which 8 (72.7%) contained a tumor, 2 cases (18.2%) had corneal issues, and 1 case (9.1%) showed inflammation within the scleral shell.

Conclusions:  Recurrence of an intraocular tumor and severe corneal degenerations are the most common cause of intrascleral prosthesis failure in dogs. Recurrent neoplasia is the most common cause of scleral shell failure in cats.

ABSTRACT NO.: 104

Iatrogenic ocular pathology: lessons for all

B. P. Wilcock* and J. Wolfer†
*Histovet Surgical Pathology, Guelph, ON, Canada; †Islington Animal Clinic, Toronto, ON, Canada

Purpose:  This study aims to improve our collective understanding of the ocular reactions to various therapeutic procedures by illustrating a variety of expected and unexpected histologic lesions occurring as sequels to enucleation, evisceration, cataract extraction, corneoscleral wound repair, intraocular aspiration cytology, cycloablation, and retinopexy.

Methods:  Retrospective histologic assessment of diagnostic samples submitted for routine diagnostic evaluation following enucleation.

Results:  Iatrogenic lesions, which were often not included in the list of concerns for which the eye was submitted, were sorted into three groups: (1) Lesions reflecting the expected outcome of the therapeutic procedure. These will be discussed to improve our collective understanding of how the therapeutic procedure impacts ocular structure and/or function. (2) Lesions that differ from the expected outcome only in quantitative terms, resulting in a failure of therapeutic efficacy or unintended bystander injury. Some reflect errors in technique, while others are just bad luck, and all represent an opportunity for improvement. (3) Outcomes that are completely unexpected.

Conclusions:  Lesions resulting from therapeutic intervention have substantial significance in terms of quality control of medical practice and providing understanding as why such procedures succeed or fail. Such lesions may be quite unrelated to the reasons for which the globe was submitted, and yet provide continuing education that is at least as valuable as the traditional ‘diagnostic’ information within the globe.

Ancillary