Swept-Source Optical Coherence Tomography Correlations Between Retina and Choroid Before and After Vitrectomy for Epiretinal Membranes

Abstract

To describe retinal and choroidal morphology before and after surgery for epiretinal membranes (ERM) in swept-source OCT (SS-OCT). Additionally, to evaluate factors responsible for visibility of the suprachoroidal layer (SCL) and suprachoroidal space (SCS). Prospective consecutive case series. Twenty-nine eyes of 29 patients with symptomatic, idiopathic ERM were included. Pars plana vitrectomy with ERM removal and ILM peeling was performed. We examined patients with SS-OCT twice preoperatively (9-12months and 1week before surgery), then postoperatively at 1week and 6 and 12months. Twelve months after surgery visual acuity improved to 20/50 (0.48 logMAR), statistically significantly higher as compared to 1week preoperatively (P < .001). Preoperative loss of visual acuity was commonly associated with progression of deformation of the plexiform layers, as central retinal thickness (CRT) did not decrease in this period, nor did photoreceptor defects increase. Choroidal thickness decreased 6months after surgery (P= .02) and remained stable until 12months postoperatively (P= .2). The outer choroidoscleral boundary was irregular in 16 eyes preoperatively but only in 4 eyes 12months post surgery. SCS and SCL were visible in 15 eyes. During the natural course of idiopathic ERM, deformation of the outer plexiform layer progresses and is associated with decreased visual acuity. Eyes with an initially irregular outer choroidoscleral boundary (CSB) recover visual acuity faster after vitrectomy with ILM peeling for ERM. Three factors are independently associated with the visibility of the SCS: disarrangement of plexiform layers, CRT, and multiple adhesion points between retina and ERM.