Assessment of retinal layers and visual rehabilitation after epiretinal membrane removal

To evaluate the changes in visual acuity, metamorphopsia, and thickness of retinal layers after epiretinal membrane (ERM) removal and to investigate factors associated with visual function. This prospective study included 52 eyes of 52 patients who underwent surgery for idiopathic ERM. Changes in visual acuity, metamorphopsia score (M-score) using M-chart, and parafoveal thickness of each retinal layer were evaluated preoperatively and at 2-month and 6-month postoperative follow-up visits. Factors associated with visual acuity and M-score were investigated. Although continuous improvement in visual acuity and decrease in the thickness of parafoveal retinal layers following ERM removal was observed, relatively slow improvement in M-score was noted with values of 0.32 +/- 0.27, 0.44 +/- 0.46, and 0.23 +/- 0.23, respectively at the defined time points. A preoperative increase in the thickness of parafoveal retina was mainly caused by increased thickness of inner retinal layers. Preoperative thickness of inner nuclear layer (INL) were closely associated with preoperative, postoperative visual acuity, and preoperative M-score (p = 0.001, 0.012, and 0.027, respectively). Compared with the postoperative improvement in visual acuity, the postoperative improvement in metamorphopsia was a rather slow process. Parafoveal INL thickness was found to be a significant structural factor for visual acuity and metamorphopsia in ERM.