Retinal relaxation following membrane peeling: Effect on vision, central macular thickness, and vector analysis of motion

Abstract

Purpose Removal of an epiretinal membrane (ERM) leads to the outward displacement of retinal vessels and visual improvement. The direction and extent of displacement in the form of a vector analysis over the posterior pole can provide a better understanding of the dynamics and duration of this process, while the magnitude might have implications in terms of visual outcome. Methods Scanning laser ophthalmoscope images of the retina of eyes undergoing ERM peeling were compared before and 6 months after surgery. Stratification was made between prominent and limited displacement, with assessment of visual acuity (VA), and central macular thickness (CMT). In three cases, using the optic nerve as reference, 50 landmarks were chosen within the posterior pole along large and small vascular structures allowing the construction of a vector map of displacement over 1 year. Results Nine eyes with prominent and 6 with limited displacement were assessed. Improvement in VA was similar for both groups, while CMT drop was greatest for the worst group. Vector analysis showed that most vascular movement occurs over the first 6 months, covers most of the posterior retina, is centered around distinct nodes, may lead to several hundred microns of displacement. Conclusions Retinal relaxation has no direct implication on visual recovery. It originates in nodes of retinal contraction. Its extent can be significant