Evaluation of the optical coherence tomography findings of patients with idiopathic epiretinal membrane.

Abstract

This study aimed to determine the relationship between basal visual acuity (VA) and basal optical coherence tomography (OCT) parameters of patients with idiopathic epiretinal membrane (iERM). The study included 200 eyes of 200 patients with iERM. In the evaluation of basal VAs, logMAR 0.3 (0.5 on Snellen chart) was accepted as the limit, and the patients were divided into two groups as Group 1 with VA values below logMAR 0.3 and Group 2 with those above logMAR 0.3. Using OCT, the ellipsoid zone (EZ), interdigitation zone (IZ), external limiting membrane (ELM) integrity, peaked appearance of EZ in the fovea, disorganization of the inner retinal layers (DRIL), central foveal thickness (CFT), maximum retinal thickness (MRT), total photoreceptor length (TPL), photoreceptor outer segment length (PROSL), photoreceptor deformity index (PDI), and inner retinal layer irregularity index (IRLII) were evaluated and compared between the groups. There were an equal number of patients in Group 1 and Group 2. The preservation of ELM, EZ, and IZ integrity and the peaked appearance of EZ in the fovea were observed at higher rates in Group 1, whereas the rate of DRIL was higher in Group 2 (p<0.05 for all). In the multiple regression analysis performed to evaluate categorical OCT parameters, only the presence of DRIL was found to be significantly associated with VA (p<0.003). CFT*, MRT*, and IRLII** were significantly lower in Group 1 (*p<0.001, **p=0.001). TPU, PROSL, and FDI were similar between the two groups (p>0.05 for all). According to the multiple regression analysis, only the presence of DRIL was correlated with lower VA values. Among the OCT parameters, an increase in CFT and MRT, as well as the IRLII value moving away from 1 were related to lower VA values.