Rapid diagnosis of retina and optic nerve abnormalities in canine patients with and without cataracts using chromatic pupil light reflex testing

Authors

  • Sinisa D. Grozdanic,

    1. Animal Eye Consultants of Iowa, 25 E Weston Drive, North Liberty, IA 52317, USA
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    • Dr Grozdanic served as a consultant for the BioMed Vision Technologies in the period 2006–2008 without receiving any honorarium. Dr Grozdanic’s laboratory received two early prototypes of Melan-100 unit in 2006 for testing purposes as a result of Dr Grozdanic’s consulting activities. Dr Grozdanic currently serves as a consultant for Neuroptics Inc, which is developing the automated pupillometer for measurement of chromatic responses in animals and humans.

  • Helga Kecova,

    1. Department of Veterans Affairs–Center for Prevention and Treatment of Vision Loss, Iowa City VA Health Care System, 601 Highway 6 West, Iowa City, IA 52246-2208, USA
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  • Tatjana Lazic

    1. Animal Eye Consultants of Iowa, 25 E Weston Drive, North Liberty, IA 52317, USA
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Address communications to:
S. Grozdanic
Tel.: (515) 291-5097
Fax: 1-877-516-6277
e-mail: sgrozdan@gmail.com

Abstract

Objective  To develop fast and reliable testing routines for diagnosing retina and optic nerve diseases in canine cataract patients based on chromatic properties of the pupillary light reflex response.

Procedures  Seventy-seven canine patients with a history of cataract and decreased vision (43 patients with cataracts and no evidence of retina or optic nerve disease, 21 patients with cataracts and retinal degeneration [RD], 13 patients with cataracts and retinal detachment [RDT]), 11 canine patients with optic neuritis (ON) and 23 healthy dogs were examined using chromatic pupillary light reflex (cPLR) analysis with red and blue light and electroretinography.

Results  Electroretinography analysis showed statistically significant deficits in a- and b-wave amplitudes in dogs with cataracts and RD, or cataracts and RDT, when compared to dogs with cataracts without evidence of retinal abnormalities. Evaluation of b-wave amplitudes showed that presence of 78.5-μV (or lower) amplitudes had high sensitivity of 100% (95% CI: 87.2–100%) and high specificity of 96.7% (95% CI: 88.4–100%) in RD and RDT. Evaluation of cPLR responses using red light showed that presence of the pupil end constriction diameter of 5.5 mm (or higher) had moderately high sensitivity of 76.5% (95% CI: 50.1–93.2%) and high specificity of 100% (95% CI: 91.2–100%) in detecting RD and RDT. Optic neuritis patients had absent cPLR responses, regardless of the visual status.

Conclusions and Clinical Relevance  Chromatic evaluation of the pupillary light reflex is a rapid and accurate test for diagnosing retina and optic nerve diseases in canine patients.

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