Two-year results of metamorphopsia, visual acuity, and optical coherence tomographic parameters after epiretinal membrane surgery

To determine the 2-year results of metamorphopsia, visual acuity, and optical coherence tomographic (OCT) parameters after epiretinal membrane (ERM) removal, and to evaluate the correlations among them.We studied 75 eyes of 75 patients with an ERM who underwent vitrectomy and membrane peeling. The best-corrected visual acuity (BCVA), metamorphopsia scores, and OCT parameters were measured at the baseline, and 1, 3, 6, 9, 12, 18, and 24 months postoperatively. M-CHARTS were used to quantify the degree of metamorphopsia.The mean BCVA, degree of metamorphopsia, and all of the OCT parameters except the photoreceptor outer segment (PROS) length improved significantly from that at the baseline at 24 months (P 0.001). However, they were not significantly different from those at 12 months. The better BCVA at 24 months was correlated with the longer PROS length at the baseline (P 0.01). The degree of metamorphopsia at 24 months was significantly correlated with that at baseline (P 0.01).A postoperative follow-up period of 12 months may be sufficient to assess the improvements induced by the ERM surgery. The preoperative PROS length was the prognostic factor for the postoperative BCVA. The preoperative degree of metamorphopsia was the prognostic factor for the postoperative degree of metamorphopsia, suggesting that surgery for ERM should be performed before development of severe metamorphopsia.