Abstract
Purpose :
Epiretinal membrane (ERM) is sometimes observed secondary to branch retinal vein occlusion (BRVO). OCT has illustrated ERM in greater detail; however, the initiation of ERM has not been demonstrated. In this study, we used en face OCT to capture the evolution and progression of ERM associated with BRVO.
Methods :
A retrospective, longitudinal observational study includes eyes with BRVO who underwent anti-VEGF injections with at least a 2-year follow-up. A 3x3-mm spectral-domain OCT (Avanti, Optovue) was obtained at each visit from the baseline to the final visit. We used En face OCT images captured with a custom segmentation to visualize subtle structural changes on the retinal surface (Ishida Y, Ophthalmology Retina 2023). The patient characteristics who had ERM following BRVO were evaluated.
Results :
In 83 eyes with BRVO, we identified pre-existing ERM at the baseline in 3 (4%) eyes and newly developing ERM during the follow-up in 12 (14%) eyes. Of these 12 eyes, the mean (SD) observational period was 48 (16) months, and the mean (SD) number of visits was 29 (12). The initiation of ERM was observed as a hyperreflective plaque on en face OCT and cross-sectional OCT (Figure 1). The mean duration between the baseline and the initiation of ERM was 30 months (Range 5 to 66 months). At the initiation, 11 (92%) eyes had active macular edema. ERM covered the whole scan area in 9 (75%) eyes with a mean (SD) duration of 5.2 (3.2) months after the initiation. The initiation of ERM was identified in the area of BRVO in 8 eyes, while 4 eyes had the initiation in the non-affected area (Figure 2). At the initiation of ERM, the mean (SD) best corrected visual acuity (BCVA) was 0.16 (0.23) LogMAR. When ERM completely or partially covered the macular, the BCVA did not change (0.15 ± 0.19 LogMAR, P = 0.86). Only one eye had more than 3-line BCVA decline and underwent vitrectomy. When we performed a regression analysis, the ischemic BRVO was a significant factor (P = 0.031) associated with ERM formation, while age, sex, total number of anti-VEGF injections, and history of photocoagulation were not (all P>0.05).
Conclusions :
En face OCT can capture a subtle initiation of ERM following BRVO as a hyperreflective plaque. The development of ERM in eyes with BRVO may correlated with ischemia. Although ERM did not decrease visual acuity in the short term, en face OCT may be a useful surveillance modality for ERM.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.