Pros and cons of internal limiting membrane peeling during epiretinal membrane surgery: a randomised clinical trial with microperimetry (PEELING).

Background: After idiopathic epiretinal membrane (iERM) removal, it is unclear whether the internal limiting membrane (ILM) should be removed. The objective was to assess if active ILM peeling after iERM removal could induce microscotomas.

Methods: The PEELING study is a national randomised clinical trial. When no spontaneous ILM peeling occurred, patients were randomised either to the ILM peeling or no ILM peeling group. Groups were compared at the month 1 (M1), M6 and M12 visits in terms of microperimetry, best-corrected visual acuity (BCVA) and optical coherence tomography findings. The primary outcome was the difference in microscotoma number between baseline and M6.

Results: 213 patients were included, 101 experienced spontaneous ILM peeling and 100 were randomised to the ILM peeling (n=51) or no ILM peeling group (n=49). The difference in microscotoma number between both groups was significant at M1 (3.9 more microscotomas in ILM peeling group, (0.8;7.0) p=0.0155) but not at M6 (2.1 more microscotomas in ILM peeling group (-0.5;4.7) p=0.1155). Only in the no ILM peeling group, the number of microscotomas significantly decreased and the mean retinal sensitivity significantly improved. The ERM recurred in nine patients in the no ILM peeling group (19.6%) versus zero in the ILM peeling group (p=0.0008): two of them underwent revision surgery. There was no difference in mean BCVA and microperimetry between patients experiencing or not a recurrence at M12.

Conclusion: Spontaneous ILM peeling is very common. Active ILM peeling prevents anatomical ERM recurrence but may induce retinal impairments and delay visual recovery.

Trial registration: NCT02146144.