Prognostic factors of visual acuity and macular morphology improvement after idiopathic epiretinal membrane surgery

Aim of the study
To assess the predictors of functional and anatomical improvement in patients with idiopathic epiretinal membrane (ERM).

Material and methods
A two-center retrospective cohort study. A review of consecutive patients with ERM who underwent pars plana vitrectomy with ERM peeling from January 2017 to December 2019. Best-corrected visual acuity (BCVA) and optical coherence tomography markers (central macular thickness [CMT], ectopic inner foveal layer [EIFL] thickness, outer nuclear layer [ONL] thickness, presence of cotton ball sign, ellipsoid zone disruption, cystoid macular edema [CME]) were collected at baseline and at one year, and included as covariates in a multivariate logistic regression model with final BCVA improvement as a binary outcome.

Results
One-hundred twenty eight eyes (125 patients) were enrolled in the study. At one-year follow-up, BCVA improvement was observed in 98 eyes (group 1 – 76.6%; BCVA 0.52 vs. 0.17, p < 0.001). BCVA stabilization or deterioration was observed in 30 eyes (group 2 – 23.4%; BCVA 0.34 vs. 0.38, p = 0.32). In group 1, preoperative BCVA was worse than in group 2 (0.52 vs. 0.34, p < 0.001). Good preoperative BCVA (OR = 2.16, p = 0.001) and young age (OR = 0.87, p = 0.011) were found to be predictors of postoperative BCVA improvement. Young age (OR = 0.81, p = 0.049) and high preoperative CMT (OR = 24.93, p = 0.048) had a positive effect on the normalization of CMT. The presence of CME had a negative effect on the normalization of CMT (OR = 0.02, p = 0.014), but no effect on the change in BCVA (OR = 0.4, p = 0.239).

Conclusions
None of the morphological signs included in this study precluded good visual recovery in long-term follow-up. Younger patients had better functional and anatomical gains.