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

Purpose: By examining patients optical coherence tomography (OCT) sections determine relation of basal visual acuity (VA) with OCT parameter , evaluate OCT findings between stage and OCT parameter which can affect visual prognosis according to classify of current ERM. Materials and Methods: Two hundred patients who have diagnosis iERM and follow-up the least a year were received into the work. All patients detailed oftalmologic symptoms , VA basal and post surgery was recorded. In OCT, ellipsoid zone (EZ), interdigitation zone (IZ), external limiting membrane (ELM), foveal bulge appearance, disorganization of inner retinal layers (DRIL), presence of cotton ball sign, central foveal, central retinal and maximum retinal thickness (CFT, CRT, MRT), inner and outer retinal thickness (IRT, ORT), inner and outer nuclear thickness (INT, ONT), ganglion and inner plexiform total thickness (GCL + IPL), photoreceptor outer segment length (PROS), total photoreceptor length (TPL), photoreceptor deformity index (PDI), inner retinal layer irregularity index (IRLII) was evaluated. Patients were divided into 4 stages according to the ectopic inner foveal layer (EIFL) classification, OCT parameters distribution by stages was determined. In patients who were undergoing surgery, relation of VA with OCT parameters was researched. Results: ELM, EZ, IZ, presence of foveal bulge, absence of DRIL and cotton ball sign were associated with better VA (p<0,001; *p=0,001; **p<0,05). From the retinal thickness values except for ORT, significant relationships were found with all (p<0,001). Significant relationship was found between basal IRLII and PROS with basal and VA after surgery on 6th and 12th month (p<0,001; *p<0,05). Relationships wasn't found between VA with basal ORT, TPL, FDI and PROS (p>0,05). In presence of EIFL, it was found that worst VA, integrity and thickness of the inner and outer retinal layers were more frequently affected (p<0,001). Conclusion: In iERM, preservation of the integrity of outer retinal layers, less retinal thickness, absence of DRIL and cotton ball sign are associated with better VA. In EIFL stating, as the stage increases, the involvement of the inner and outer retinal layers increases and VA decreases. IRLII and PROS are OCT parameters that can be used to determine baseline or postoperative VA. Keywords: Visual acuity, Idiopathic epiretinal membrane, Inner retinal layer irregularity index, Optical coherence tomography