Are There Funduscopic and Optical Coherence Tomography Preoperative Characteristics to Predict Surgical Difficulty of Epiretinal Membrane Removal?

To identify the correlation between preoperative funduscopic and optical coherence tomography characteristics of epiretinal membranes and the difficulty of surgical removal. Fifty eyes of 50 patients with an idiopathic epiretinal membrane (ERM) scheduled for pars plana vitrectomy (PPV) and ERM peeling were included. Surgical videos were analyzed and the difficulty of ERM removal (easy or difficult) determined subjectively by an independent surgeon. Furthermore, the peeling time and amount of grasping were measured on the videos to provide an objective factor of surgery difficulty. Preoperative spectral-domain optical coherence tomography (OCT) images and color fundus photos were analyzed to identify predictive factors for membrane removal difficulty. The subjective surgical difficulty of ERM removal was strongly associated with fibrillary changes between the ERM and retinal nerve fiber layer (RNFL), severe retinal vascular tortuosity and severe glinting fundus reflex. Higher fundus pigmentation was associated with fewer and cystoid spaces with more attempts of grasping ERM. No other preoperative signs were found to be associated with the duration of the peeling time. The presence of fibrillary changes between the ERM and RNFL, severe retinal vascular tortuosity and severe glinting reflex are preoperative findings that have a strong association with the difficulty in ERM peeling.