Visual outcome and prognostic factors after surgery for a secondary epiretinal membrane associated with branch retinal vein occlusion

Purpose: To assess the visual outcome and prognostic factors after surgery for a secondary epiretinal membrane (ERM) due to branch retinal vein occlusion (BRVO). Methods: Medical records of 33 patients (33 eyes) were retrospectively reviewed. All patients underwent vitrectomy and completed at least one year of follow-up. Patients characteristics, including baseline best-corrected visual acuity (BCVA; logMAR, logarithm of the minimum angle resolution), fluorescein angiography and optical coherence tomography findings were analyzed. Results: Twenty eyes (60.6%) were non-ischemic and nine eyes (27.3%) had ischemic maculopathy. The mean BCVA was 0.82 ±0.56 logMAR (20/132 Snellen equivalent) at baseline and 0.43 ±0.37 logMAR (20/53 Snellen equivalent) at 1 year (p = 0.001). At 1 year three eyes (9.1%) had visual loss with 0.3 logMAR or more deterioration than baseline whereas 16 eyes (48.5%) gained vision. The mean central macular thickness (CMT) was 407.3 ±138.8 μm at baseline and 274.71 ±40.5 μm at 1 year after surgery (p = 0.001). Photoreceptor integrity was intact in 20 eyes (60.6%). Photoreceptor integrity (B = 0.248, p = 0.001) at baseline was significantly correlated with visual outcome after surgery. Conclusion: Surgery for a secondary ERM associated with BRVO led to a relatively favorable visual outcome. The integrity of photoreceptors at baseline seems to be useful in predicting visual outcome in these patients.