Rate and Severity of Epiretinal Membrane Formation after Pneumatic Retinopexy for Rhegmatogenous Retinal Detachment

Abstract

Purpose : To report the rate and severity of epiretinal membrane (ERM) formation after pneumatic retinopexy (PR) for rhegmatogenous retinal detachment (RRD).

Methods : A single center, retrospective chart review of all patients who underwent PR for RRD between January 2015, and June 2022, and developed subsequent ERM was done. Those who had prior ERM were excluded. Optical coherence tomography (OCT) structural analysis and ERM grading were based on a previously reported scale.

Results : 161 of 728 eyes (22.12%) of 728 patients who underwent PR developed subsequent ERM. 119 eyes of 119 patients were included in this study after excluding those with prior surgery for RRD or retinal tears. 72 (60.50%) were males and 47 (39.50%) were females; mean (SD) age was 65.73 (9.83) years. 68 (57.14%) had macula-involving RRD while 51 (42.86%) had macula-sparing RRD. Mean (SD) follow up from the date of PR was 1133.44 (739.97) days.
Mean (SD) log MAR visual acuity (VA) [Snellen] at the time of the PR was 2.21 (7.95) [20/3244]. Mean (SD) time until ERM diagnosis after PR was 371.47 (464.49) days. At ERM diagnosis, patients had an improved mean (SD) log MAR VA [Snellen] 0.536 (0.56) [20/77] compared to before PR (p= 0.034). The severity of ERM at the time of initial diagnosis was grade 1 in 79 (70.54%) eyes, grade 2 in 15 (13.39%), grade 3 in 11 (9.82%) and grade 4 in 7 (6.25%). Note that 5 eyes were ungradable due to missing or poor-quality OCT images.
101 eyes (84.87%) were observed while 18 (15.13%) underwent membrane peels. Of the eyes that had membrane peels, only 2 (11.11%) had recurrence of ERM afterwards. Final mean (SD) log MAR VA [Snellen] after membrane peel was 0.865 (0.75) [20/147] compared to 1.23 (0.74) [20/340] before (p= 0.061).
12 (10.08%) eyes had no ERM at final visit while the remaining 107 (89.02%) had ERM. Final ERM grades were distributed as follows: 77 (64.71%) grade 1, 12 (10.08%) eyes grade 2, 12 (10.08%) eyes grade 3 and 3 (2.52%) eyes had grade 4; (three patients were lost to follow up and were not graded). Mean (SD) log MAR visual acuity [Snellen] at final visit was 0.395 (0.49) [20/50], which improved compared to VA at the time of the PR (p= 0.018) and compared to VA at ERM diagnosis (p < 0.001).

Conclusions : ERM is a common complication that develops around 1 year post PR for RRD with the vast majority remaining fairly mild (grade 1 or 2).

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.