Postoperative change in the retinal artery angle after vitrectomy surgery in eyes with idiopathic epiretinal membrane

We investigated the relationship between time-course changes in the retinal artery angle and metamorphopsia in eyes with idiopathic epiretinal membrane (ERM). Over all, Thirty-seven patients who underwent vitrectomy surgery for ERM were enrolled. In addition to visual acuity (VA), the metamorphopsia score was measured for each eye using M-CHARTS. Moreover, pre- and postoperative retinal artery angle (YCA) was measured using ImageJ software. The difference between pre- and postoperative metamorphopsia score (Mdif), the difference between pre- and postoperative CRT (CRTdif) and the ratio of postoperative YCA to preoperative YCA (pYCA) were calculated and used for the statistical analysis. We investigated the relationship between Mdif and each of age, axial length (AL), pYCA, CRTdif and the follow-up duration. The association of pYCA with Mdif was also investigated in improved VA group (gained at least 0.2 logMAR) and unimproved VA group (gained less than 0.2 logMAR). The logMAR VA and metamorphopsia score significantly improved after vitrectomy surgery (both p < .001). The postoperative YCA was significantly larger than the preoperative YCA (p < .0001). Among age, AL, pYCA, CRTdif and the follow-up duration, pYCA and the follow-up duration were significantly associated with Mdif. Subgroup analysis indicated pYCA was significantly related to Mdif in unimproved VA group, but not in improved VA group. Monitoring the time-course change in the retinal artery angle might be useful for predicting the improvement in metamorphopsia after vitrectomy surgery in ERM eyes.