Anatomical and Functional Factors Influencing Recovery in Idiopathic Epiretinal Membrane After Surgery

Background: Idiopathic epiretinal membranes (iERMs) are treated with pars plana vitrectomy and epiretinal membrane peeling. Simultaneous internal limiting membrane (ILM) peeling could reduce the recurrent rate. We aimed to explore the anatomical and functional factors influencing recovery outcomes in patients with iERM after surgical intervention. Methods: We enrolled 85 eyes of 85 participants with iERM who underwent pars plana vitrectomy with ERM and ILM peeling from January to December 2020 in Kaohsiung Veterans Hospital. We analyzed ERM staging, preoperative and postoperative vision and findings of retinal microstructures, and thickness changes determined using optic coherence tomography (OCT), as well as pre- and postoperative inner and outer retinal layer thickness changes. Results: The mean age was 65.64 ± 6.19 years, and no ERM recurrence was observed within one year. Males comprised 44.71% of participants (38/85). The mean preoperative vision score was 0.47 [Snellen equivalent (SE), 68/200] ± 0.29 logMAR, and the mean final vision score was 0.32 (SE, 96/200) ± 0.30 logMAR. Visual improvements were significant (p < 0.001, paired t-test). Preoperative vision (β = 0.327, p = 0.010) and final lens status (β = 0.400, p = 0.002) were significantly correlated with final vision (R² = 0.309). Central foveal thickness and inner and outer retinal layer thickness decreased continuously until 12 months postoperatively in the pseudophakia group, whereas for those in the phakia group, the outer retinal layer thickness only decreased in the first 6 months. Conclusions: Poor initial vision and final phakia significantly worsened final visual outcomes. Postoperative vision, central foveal thickness, and thickness of the inner and outer retinal layers showed the continuous statistical improvement in pseudophakic eyes over 6 months.