To evaluate surgical outcomes of idiopathic epiretinal membrane (ERM) with good visual acuity.

We evaluated patients who were diagnosed with idiopathic ERM with best corrected visual acuity (BCVA) greater than 20/40 and who were followed-up for 12 months or longer after vitrectomy and membrane removal. BCVA, metamorphopsia, central subfield macular thickness (CSMT), foveal contour, and status of photoreceptor inner/outer segment (IS/OS) junction were retrospectively assessed based on the medical records and optical coherence tomography (OCT) images.

Twenty-four eyes were included in the present study. The mean BCVA (log MAR) did not significantly improve from baseline to 12 months after surgery (0.26 ± 0.06 and 0.25 ± 0.19, respectively). Six eyes showed improved vision of two or more lines, and six eyes had decreased vision of two or more lines. Metamorphopsia remained in all four eyes with preoperative symptoms until 12 months postoperatively. CSMT decreased significantly from 418 ± 86 µm at baseline to 343 ± 45 µm at 12 months ( p < 0.01). Among 17 eyes without foveal depression at baseline, 11 eyes recovered a foveal depression at an average of 6.6 months after surgery. IS/OS status at baseline was intact in 19 eyes, attenuated in three eyes, and disrupted in two eyes and did not change significantly at 12 months.

Surgical treatment for idiopathic ERM with good visual acuity resulted in anatomical but not functional improvement. Choosing surgery for idiopathic ERM with good visual acuity should be considered carefully because decreased visual acuity could result in some patients.