Intraoperative Grasp Site Correlation With Morphologic Changes in Retinal Nerve Fiber Layer After Internal Limiting Membrane Peeling

BACKGROUND AND OBJECTIVE: Recent reports have demonstrated inner retinal changes after internal limiting membrane (ILM) peeling, but the mechanism responsible for these findings remains poorly understood. The purpose of this report is to establish a correlation between ILM removal and postoperative morphologic changes. PATIENTS AND METHODS: Prospective, observational case series of eight consecutive patients undergoing pars plana vitrectomy with ILM peeling for macular hole or epimacular membrane. Intraoperatively, all grasp sites were recorded and subsequently superimposed on postoperative infrared and spectral-domain optical coherence tomography (SD-OCT) images. Repeat examination and imaging were performed at regular postoperative intervals. RESULTS: Infrared fundus photography revealed well-defined, hyporeflective arcuate striations in all patients during the early postoperative period. These defects followed the course of axonal pathways from the grasp site to the optic nerve. SD-OCT images on all patients revealed early focal nerve fiber layer swelling directly corresponding to grasp sites, with eventual atrophy. CONCLUSION: A dynamic process takes place within the inner retina following surgical removal of ILM. Inadvertent surgical trauma induced by ILM forceps may be the mechanism responsible for nerve fiber layer morphologic changes after ILM peeling.