The role of internal limiting membrane peeling in epiretinal membrane surgery: a randomised controlled trial

Purpose To compare the anatomical and functional outcomes after primary idiopathic epiretinal membrane (ERM) peeling with or without internal limiting membrane (ILM) peeling. Design A two-centre randomised, controlled clinical trial with 12 months of follow-up. Methods One hundred and two eyes of 102 patients were included in the analysis and were randomised into two groups (ILM peeling (P) and non-ILM peeling (NP) group). Inclusion criteria were: Idiopathic ERM confirmed on optical coherence tomography, age =18 years, binocular distortion, best-corrected visual acuity (BCVA) =90 ETDRS letters, intraocular pressure =23 mm Hg and informed consent. The primary outcome measure was the mean change in the ETDRS distance BCVA at 12 months' follow-up for each group. Results The mean change in distance BCVA at 12 months was 0.30 +/- 0.24 logMAR (15 ETDRS letters) in the P group and 0.31 +/- 0.23 logMAR (14 ETDRS letters) in the NP group, a change that was not statistically significant (p=0.84). No statistically significant differences were observed when comparing the changes in distance BCVA, the changes in metamorphopsia (Amsler grid) and the changes in central retinal thickness between the two groups at any of the time points studied. Conclusions Our analysis suggests that ILM peeling in idiopathic ERM surgery does not result in better visual improvement. The more frequent presence of an uninterrupted interdigitation zone in the P group did not result in a better functional outcome of our patients. No recurrent ERMs were noted in either group.