Conflict/competing interest: None declared.
Does unintentional macular translocation after retinal detachment repair influence visual outcome?
Article first published online: 15 NOV 2011
© 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists
Clinical & Experimental Ophthalmology
Volume 40, Issue 1, pages 88–92, January/February 2012
How to Cite
Pandya, V. B., Ho, I.-V. and Hunyor, A. P. (2012), Does unintentional macular translocation after retinal detachment repair influence visual outcome?. Clinical & Experimental Ophthalmology, 40: 88–92. doi: 10.1111/j.1442-9071.2011.02666.x
Funding sources: None declared.
- Issue published online: 5 FEB 2012
- Article first published online: 15 NOV 2011
- Accepted manuscript online: 22 AUG 2011 09:31PM EST
- Received 3 March 2011; accepted 12 July 2011.
- fundus autofluorescence;
- macular translocation;
- retinal detachment
Background: To document the occurrence of postoperative macular translocation after retinal detachment repair and discuss its influence on visual outcome.
Design: Retrospective case series in a tertiary care setting.
Participants: Five eyes of five patients presenting to our clinic with macula-off rhegmatogenous retinal detachment.
Methods: All patients underwent surgical repair of the retinal detachment, with regular postoperative follow-up, including macular optical coherence tomography and fundus autofluorescence.
Main Outcome Measures: Visual acuity and subjective visual symptoms in patients with anatomically successful retinal detachment repair, in whom inadvertent macular translocation was noted.
Results: Our series demonstrates the presence of unintentional macular translocation after retinal detachment repair, detected by fundus autofluorescence imaging. In contrast to previous reports, we document inadvertent macular translocation in one patient after scleral buckling surgery. In each case, the retina was fully reattached postoperatively and no other complications were identified. There was variability in the symptoms and objective visual outcomes after surgery.
Conclusions: Inadvertent macular translocation can occur following repair of macula-off retinal detachment, and may be a significant contributor to poorer visual outcome after retinal detachment, despite objective surgical success.
Surgical repair of rhegmatogenous retinal detachment most commonly involves pars plana vitrectomy (PPV), the scleral buckle procedure, pneumatic retinopexy or a combined PPV/scleral buckle, depending on several patient factors.1 Although the anatomical success rate of single surgery may be as high as 94%, the recovery of vision is often delayed and variable.2 In patients with phakic retinal detachment, a recent large European trial has indicated that scleral buckle surgery provides a significantly greater improvement in best corrected visual acuity (BCVA) compared with primary PPV.3 Conversely, in pseudophakic patients, primary PPV or a combined PPV/scleral buckle have been shown to have a significantly higher probability of a favourable anatomical and visual outcome.4 Several complications can affect the final visual outcome, including cystoid macular oedema, persistent subretinal fluid, epiretinal membrane, recurrent retinal detachment and proliferative vitreoretinopathy (PVR).5
Fundus autofluorescence (FAF) imaging has emerged as a useful tool in the assessment of retinal pathology. It is based on the intrinsic fluorescent properties of specific endogenous molecules in the retina, particularly lipofuscin.6 It is accepted that in metabolically active or senescent cells of the retinal pigment epithelium (RPE), there are increasing amounts of lysosomes containing lipofuscin, most likely as a product of photoreceptor outer segment turnover.7 Therefore, areas of hyperfluorescence may be indicative of retinal ageing, trauma, degeneration or inflammation. Although it is a relatively new technology in everyday practice, it has recognized applications in the clinical and scientific study of age-related macular degeneration (AMD), central serous retinopathy and retinal dystrophies.8–10
We report a series of patients in whom inadvertent retinal (including macular) translocation was noted postoperatively, detected by FAF, in the absence of other complications, with variability in the visual result.
This series encompassed the time period between July 2010 and February 2011, with the clinical records of each patient reviewed retrospectively. Fundus photographs and FAF images were obtained using a Zeiss FF-450 Plus IR fundus camera. Optical coherence tomography (OCT) images were obtained using the Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA, USA), with 5-line raster sequences used to assess the macula postoperatively. The findings are presented in the following.
The key features of each case are summarized in Table 1. All patients were male and had macula-off rhegmatogenous retinal detachments. Postoperative fundus photographs with corresponding FAF images are shown in Figure 1. Four out of five patients underwent vitrectomy for the repair of their retinal detachment, using 23-gauge PPV with either the Accurus Surgical System or Constellation Vision System (Alcon Laboratories, Inc., Fort Worth, TX, USA). Furthermore, after standard PPV was completed, all of these patients had internal drainage of subretinal fluid via a posterior drainage retinotomy. Heavy liquid (perfluorocarbon) was not used to flatten the retina in any case.
|Case||Age (years)||Affected eye||Lens||Repair||Preoperative BCVA||Postoperative BCVA||Follow-up (months)|
A 58-year-old man presented with a 3-week history of floaters and a progressive nasal field defect in his right eye. He was diagnosed with a macula-off retinal detachment and underwent standard PPV with 28% sulphur hexafluoride (SF6) gas tamponade and cryotherapy to the retinal break. Postoperatively, clinical examination and assessment with OCT showed complete reattachment and no residual subretinal fluid or oedema.
A 24-year-old man presented with a 2-day history of distorted vision in his right eye, but no other significant symptoms. He had a macula-off retinal detachment, with retinal dialysis at the temporal periphery. A scleral buckle (287 buckle/240 band) was performed, with cryotherapy to the retinal break, external drainage of subretinal fluid (via scleral cutdown technique) and tamponade with 0.3 mL of 100% SF6 gas. On follow-up, he was noted to have residual subfoveal fluid on OCT, which resolved gradually over 6 weeks.
A 73-year-old man presented with a 2-week history of flashes and floaters in his left eye, followed by sudden reduced vision. He had a subtotal macula-off retinal detachment and underwent standard PPV, with cryotherapy, endolaser and tamponade with 14% perfluoropropane (C3F8). About 6 weeks after surgery, the retina was fully reattached and OCT did not demonstrate any abnormalities. However, he complained of vertical diplopia, which was compensated for by a prismatic spectacle lens. At final follow-up, his diplopia had resolved, he no longer required the prism, and the retina remained attached.
A 49-year-old man presented with sudden onset of a dark shadow in his right eye and poor vision. He was found to have a subtotal macula-off retinal detachment, for which he underwent standard PPV with 24% SF6 tamponade and cryotherapy. About 3 months after surgery, he complained of vertical diplopia and metamorphopsia. His visual acuity was 6/24 and the retina was completely attached with no macular abnormality on OCT. At final follow-up, his visual acuity was 6/18 and his diplopia had improved with a prismatic correction.
A 66-year-old man presented with a sudden onset of visual loss in his right eye. He had an inferior macula-off retinal detachment, with multiple breaks and lattice degeneration. He underwent standard PPV with cryotherapy, endolaser and 24% SF6 tamponade. He noted diplopia and metamorphopsia postoperatively and at 1 month, was found to have an inferior macula-on redetachment. He underwent repeat PPV with insertion of silicone oil. Following silicone oil removal, the retina remained attached but his vertical diplopia and distortion persisted. The diplopia was relieved with prismatic correction in his spectacles.
Our series demonstrates the occurrence of unintentional macular translocation following the surgical repair of retinal detachment. As shown in Figure 1, the hyperfluorescent outline of retinal blood vessels is seen superior to their postoperative position, indicative of inferior displacement of the retina. It is presumed that in the immediate period after surgery, a small amount of subretinal fluid persists, which allows the retina to displace inferiorly under the influence of gravity, if the patient assumes an upright position. Therefore, we would emphasize the importance of promptly assuming and maintaining the appropriate face-down position following repair of macula off retinal detachment. Alternatively, translocation may occur intraoperatively because of posterior displacement of subretinal fluid when draining via a retinotomy. In the recent study by Shiragami et al. no posterior retinotomies were performed; in contrast, all patients in our study undergoing PPV had subretinal fluid drained via posterior retinotomies. Shiragami et al.11 demonstrated that the extent of retinal detachment and macula-off status were significantly associated with postoperative retinal displacement (odds ratio 7.7 and 10.9, respectively).11 In their series, all cases of macular translocation occurred after standard PPV; it is therefore notable that in our series, one patient (Case 2) had unintentional translocation after a scleral buckle procedure.
Given the proposed mechanisms of translocation, it is important to consider the different techniques used for subretinal fluid drainage. In the case of the scleral buckle procedure, external drainage of the subretinal fluid can be performed in various ways including the scleral cutdown technique, direct trans-scleral needle drainage or using laser.12,13 Despite direct visualization using the indirect ophthalmoscope, it is likely that at least some fluid will remain in the subretinal space at the end of the case. Wolfensburger prospectively evaluated the time course of foveal reattachment after successful retinal detachment repair, as assessed by clinical examination and OCT. In patients who underwent scleral buckling with or without external drainage, 67% at 1 month, 45% at 6 months and 11% at 12 months had persistent subfoveal fluid.14 In contrast, in this same study, no patients who underwent vitrectomy had any residual subretinal fluid at 1-month follow up. However, in the context of our paper, the presence of subretinal fluid immediately after surgery is more relevant to whether retinal translocation may occur. Internal drainage of subretinal fluid was performed via the retinal break and a posterior drainage retinotomy in all four patients who underwent PPV, in order to minimize the amount of subclinical fluid at the end of the case. In contrast, if internal drainage is performed via the peripheral break alone, it is probable that the amount of residual fluid will be greater, with the resultant risk of translocation. A useful adjunct to the above is the use of perfluorocarbons (heavy liquids) to flatten the posterior pole retina and anteriorly displace fluid away from the macula, thereby allowing more complete subretinal drainage.15 In this instance, the posterior drainage retinotomy may be avoided. Given the above considerations, we would again emphasize the importance of immediate face-down posturing after repair of macula-off detachments, ideally on the operating table/trolley when the case is completed.
The reason for increased autofluorescence at the original position of the retinal blood vessels is not clear. It is hypothesized that the photoreceptors underlying the vascular structures have not been exposed to light, and thus the corresponding RPE cells have become metabolically quiescent. Subsequently, with retinal translocation and sudden illumination, increased photoreceptor activity leads to an accumulation of lipofuscin in the RPE, with resultant hyperfluorescence on FAF imaging.7 In contrast, FAF signals in other conditions such as solar retinopathy or AMD may arise via a different mechanism: a central area of hypofluorescence corresponding to atrophy, and a surrounding border of hyperfluorescence associated with larger pleomorphic RPE cells clearing the resultant cellular debris.16 It is notable that in areas of increased autofluorescence, no vascular abnormalities have been detected with fluorescein angiography, which supports the metabolic hypothesis of FAF.11
Visual distortion after retinal detachment surgery, in the absence of any obvious abnormality, may be explained by macular translocation. One of our patients (Case 4) complained of metamorphopsia at 3 months postoperatively, in the absence of clinical or high-resolution OCT evidence of macular abnormality. This clinical picture is well documented in patients undergoing macular translocation for neovascular AMD, and may also be associated with changes in retinal sensitivity and fixation stability.17 In addition, three patients complained of primarily vertical diplopia, consistent with inferior displacement of the retina; however, this symptom recovered in one patient, most probably because of sensory fusion in the central nervous system.
In summary, our limited case series demonstrates the phenomenon of macular translocation after successful retinal detachment repair, detected by FAF imaging. Of particular importance is the occurrence of unintentional translocation after a scleral buckle, which has not been previously reported in the literature. This event may have a significant influence on the final functional outcome and warrants further investigation in a larger, prospective study. Finally, FAF represents a useful tool in the postoperative assessment of patients after retinal detachment repair, particularly when the visual outcome is suboptimal and no abnormality is evident on clinical examination or other investigation such as OCT.
We would like to thank Mr Douglas Nash for assistance with preparation of the images for this paper.