The purpose of this study is to evaluate the changes in visual acuity, metamorphopsia, and thickness of retinal layers after epiretinal membrane removal and to investigate factors associated with visual function.

Eyes with idiopathic Epiretinal Membrane Removal (ERM) scheduled to underwent ERM removal were included. 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.

Inclusion Criteria:

• Patients who were diagnosed with idiopathic epiretinal membrane and were scheduled for epiretinal membrane removal

Exclusion Criteria:

• evidence of ocular inflammation, diabetic retinopathy, hypertensive retinopathy, and retinal vasculitis, media opacity that would influence visual acuity or preclude acquisition of clear spectral domain optical coherence tomography images,
• presence of cataract judged to affect visual function, -6.0 diopters or more of spherical equivalent, prominent staphyloma, history of intraocular surgery other than uncomplicated cataract surgery, history of retinal detachment, other ocular diseases that may influence the macular microstructure or visual function, immeasurable fovea location on the spectral domain optical coherence tomography image due to severe retinal contraction, and indistinct intraretinal structure on spectral domain optical coherence tomography images.
• patients who underwent combined epiretinal membrane removal and cataract extraction, less than six months follow-up after epiretinal membrane removal, who had occurrence or progression of cataract after the surgery judged to affect visual function, or who experienced recurrence of epiretinal membrane during the follow-up period