Schisis of the Retinal Nerve Fiber Layer in Epiretinal Membranes

Abstract

To describe schisis of the retinal nerve fiber layer (sRNFL) associated with epiretinal membranes (ERMs) seen on spectral-domain optical coherence tomography (OCT) prior to vitreoretinal surgery. Areas of sRNFL (size and location) were noted during preoperative planning. Spectral-domain OCT scans were obtained to study the inner retinal morphology postoperatively. Retrospective observational consecutive case series. Pre- and postoperative spectral-domain OCT and en face images of 41 eyes with ERMs that had undergone vitrectomy by a single surgeon were analyzed to record the presence of sRNFL. The extent of sRNFL was classified as focal or diffuse. Other characteristics such as involvement of the papillomacular bundle and areas of fibrillary protrusion of sRNFL above the internal limiting membrane (ILM) were documented. Color fundus photographs were reviewed to correlate with the spectral-domain OCT images. Mean patient age and length of follow-up were 69.3 years (range 52-82 years) and 6.8months (range 0.25-21months), respectively. Mean preoperative and postoperative central thicknesses were 477μm and 387μm, respectively (P < .0001). sRNFL was observed in 51.2% (21/41 eyes), and was classified as diffuse (>1 disc diameter) in 90.5% (19/21 eyes). Protrusion of sRNFL through the ILM was present in 76.2% (16/21 eyes) and occurred in areas of dehiscence of the adjacent ILM. sRNFL was best visualized on spectral-domain OCT and en face imaging at the vitreoretinal interface and sometimes correlated with areas of retinal whitening. sRNFL resolved in all cases postoperatively. sRNFL was a relatively common occurrence in ERMs, correlated frequently with areas of dehisced ILM intraoperatively, and resolved postoperatively in all cases.