Analyses of Tangential Retinal Displacement and Metamorphopsia after Idiopathic Epiretinal Membrane Surgery

ABSTRACT

Purpose@#To evaluate the correlation between tangential retinal displacement and the improvement of metamorphopsia after idiopathic epiretinal membrane surgery. @*Methods@#The medical records of 36 eyes from 36 patients with idiopathic epiretinal membrane who underwent pars plana vitrectomy and who were observed over 1 year between January 2017 and December 2018 were retrospectively reviewed. Preand postoperative visual acuity, vertical and horizontal metamorphopsia score using the M-CHART, vertical and horizontal retinal displacement, and the presence of an ectopic inner foveal layer (EIFL) using optical coherence tomography were investigated. @*Results@#Postoperatively, the ratios of vertical and horizontal retinal displacement were 12.11 ± 12.04% and 8.09 ± 11.43%, respectively. The postoperative horizontal metamorphopsia score significantly improved (p = 0.019) compared to preoperatively and there were no significant differences in the vertical metamorphopsia score (p = 0.790). There were no significant correlations between the ratio of the vertical retinal displacement and improvement of horizontal metamorphopsia score or between the ratio of the horizontal retinal displacement and improvement of vertical metamorphopsia score. The preoperative horizontal metamorphopsia score was significantly higher in patients with EIFL than in patients without EIFL (p = 0.021) as was the postoperative horizontal metamorphopsia score (p = 0.016). In the EIFL group, the disappeared EIFL group had significantly lower postoperative vertical (p = 0.001) and horizontal (p < 0.001) metamorphopsia scores compared to the persistent EIFL group. @*Conclusions@#Postoperative retinal displacement was not correlated with improvement in metamorphopsia. However, the presence of preoperative EIFL and postoperative changes affect the severity of postoperative metamorphopsia.