Idiopathic epiretinal membranes: postoperative changes in morphology.

Objective: To describe retinal morphology in idiopathic epiretinal membranes (ERMs) and to evaluate factors influencing function at different postoperative times up to 24 months.

Design: Retrospective study.

Participants: A total of 121 eyes of 117 patients followed with spectral-domain optical coherence tomography for 24 months.

Methods: The following details were analyzed: type of ERM, central retinal thickness, and status of all retina layers in the fovea, especially the outer nuclear layer (ONL) and photoreceptor layer. We evaluated the presence of disorganization of retinal inner layers (DRIL), ectopic inner foveal layer (EIFL), elevation (stretching) of the ONL, cotton ball sign, and type connection between the retina and ERMs (complete adherence or multiple junction spots).

Results: The percentage of DRIL, EIFL, and stretched ONL decreased. Several factors negatively influenced visual acuity during the early postoperative controls: age, interdigitation zone defects; presence of cotton ball sign, DRIL, EIFL, and stretched ONL; and strong adhesion of the ERMs to the retina. Twenty-four months after surgery, only DRIL and strong adhesion between ERMs and the retina remained statistically significant.

Conclusions: Younger patients (p < 0.001) and patients without DRIL (p < 0.001) experienced a faster recovery of function. The length of follow-up was associated with a decrease of factors influencing the final outcome. After 24 months, only the presence of DRIL and strong adhesion between the ERMs and the retina were significant. Assuming that DRIL appears in more advanced stages when compared with EIFL, this allows us to suggest that earlier surgery might be of more benefit in idiopathic ERMs.