Topographic changes in macula and its association with visual outcomes in idiopathic epiretinal membrane surgery

Purpose We investigated changes in macular topography and their association with visual acuity and metamorphopsia in the idiopathic epiretinal membrane (iERM). Methods Twenty-four eyes that underwent vitrectomy and ERM removal with internal limiting membrane peeling were included in this study. Best-corrected visual acuity (BCVA) and horizontal/vertical metamorphopsia scores (h and vM-scores in the M-chart) were assessed. The distances of fovea-disc (FD) and fovea-vascular arcade (FV), central subfield macular thickness (CSMT), and foveal location were measured using fundus photography, optical coherence tomography (OCT), and OCT angiography, respectively. Results The BCVA (logMAR) and vM-scores (P < 0.001, P = 0.014, respectively) improved after surgery. The distance of the FD decreased (P < 0.001) and FVs increased (P < 0.001, both). The fovea moved horizontally toward the disc (P < 0.001). The change in median total FVs (7.114 mm to 7.369 mm, P = 0.001) correlated with the change in BCVA (P = 0.049, Pearson's [r] = -0.404). No topographic parameters were associated with an improvement in the vM score. Conclusions The macular topography significantly changed after iERM removal; the fovea moved nasally, and the distance between the superior and inferior vascular arcades increased. Such a change was relevant to the improvement in BCVA, but not metamorphopsia.