Inner and outer parafoveal retinal layers on OCT as predictors of visual outcome in idiopathic epiretinal membrane surgery

Abstract

Purpose To evaluate whether the pre- operative morphological and thickness-related characteristics of retinal layers in the foveal region detected by spectral-domain optical coherence tomography (SD-OCT) are correlated with visual outcome after epiretinal membrane (ERM) removal by pars plana vitrectomy (PPV) with internal limiting membrane peeling. Methods Eighty-two eyes of 82 consecutive patients with idiopathic ERM and a pre-operative visual acuity of ≤20/40 were recruited retrospectively. Patients with full- thickness macular hole, diabetic retinopathy, retinal detachment were excluded. The best-corrected visual acuity (BCVA), whole para- foveal thickness (PFT), inner PFT, outer PFT (Fig.1A) were recorded before and 6-months after surgery. Multiple logistic regression analysis was performed to identify independent predictors of post- operative visual outcome. Results Post-operative (Post-Op) BCVA was positively correlated with pre- operative (Pre-Op) BCVA(p<.0001). A smaller Post-Op outer PFT was positively correlated with BCVA improvement by at least 2Lines(p=.030). Pre-Op outer PFT(p=.004) and disorganisation of retinal layers(Fig.1B)(p=.019)were identified Pre-Op predictors of Post- Op outer PFT. Conclusions Pre-Op larger outer PFT and presence of disorganised retinal layers were identified as predictors of Post-Op visual acuity improvement in eyes with idiopathic ERM.