Correlation between Metamorphopsia and Epiretinal Membrane Optical Coherence Tomography Findings

Purpose To examine the retinal morphologic features of metamorphopsia caused by epiretinal membrane (ERM) and to determine whether spectral-domain optical coherence tomography (SD-OCT) correlated with metamorphopsia. Design Retrospective case series. Participants This study included 19 eyes of 19 patients with ERM diagnosed by clinical ophthalmic findings and SD-OCT. Methods The 19 eyes were classified into 3 groups based on Amsler chart results: no metamorphopsia (n = 4), local metamorphopsia (n = 8), and broad metamorphopsia (n = 7). The thickness of the 3 inner retinal layers: inner nuclear layer (INL), outer plexiform layer (OPL), and outer nuclear layer (ONL), on 5 horizontal SD-OCT cross-sections (1 line through the fovea, 2 regularly spaced lines superior to the fovea, and 2 regularly spaced lines inferior to the fovea) were measured using the electronic calipers of the SD-OCT system. Main Outcome Measures Correlation between INL, OPL, and ONL thickness with metamorphopsia and visual acuity. Results Metamorphopsia was detected in the same position as edematous areas of the INL with a thickness >50 μm. The maximum INL thickness was relatively significantly different between the subjects with no metamorphopsia and those with local or broad metamorphopsia (vs local, P = 0.06; vs broad, P = 0.04). Visual acuity significantly correlated with both maximum INL thickness (A = −0.681; P = 0.001) and maximum ONL thickness (A = −0.708; P