Epiretinal membrane peeling in eyes with pseudophakia: prognostic and morphological factors of visual outcomes

In patients with symptomatic epiretinal membrane (ERM), pars plana vitrectomy (PPV) and ERM peeling, followed by internal limiting membrane (ILM) peeling is the most common treatment. In this study, spectral domain optical coherence tomography (SD-OCT) was used to investigate the predictive factors of visual outcomes in patients with pseudophakic ERM following surgery. The records of 61 pseudophakic eyes with ERM undergoing PPV, ERM peeling, and ILM peeling were retrospectively reviewed. OCT features such as central foveal thickness (CFT), cotton ball sign, ERM foveoschisis, ellipsoid zone (EZ) disruption, external limiting membrane (ELM) disruption, ectopic inner foveal layer (EFIL), disorganization of the retinal inner layers (DRIL), dissociated optic nerve fiber layer (DONFL), and microcystic macular edema (MME), as well as surgical factors, were compared before and after surgery. The correlations between the OCT and surgical factors and change of best-corrected visual acuity (BCVA) before and after surgery were examined. The mean follow-up time was 6 months. BCVA (P < 0.01) and CFT (P < 0.01) showed significant improvements after ERM removal. McNemar test results indicated that only the cotton ball sign (P = 0.002) and DRIL (P < 0.001) exhibited statistically significant improvement after surgery. Multiple linear regression analyses showed that ERM-foveoschisis (P = 0.015) and MME (P = 0.009) were significantly correlated with less improvement of visual acuity, while better visual acuity before surgery was significantly associated with better improvement of visual acuity (P < 0.01). Better baseline visual acuity is correlated with better visual acuity improvement after surgery, while ERM foveoschisis and MME identified preoperatively on OCT are associated with relatively less improvement of visual acuity.