Effect of Anti–Vascular Endothelial Growth Factor Therapy on Corneal Nerves

Abstract

PURPOSE: Vascular endothelial growth factor (VEGF) is a trophic factor for corneal nerves (CNs). Despite its widespread use to treat a variety of retinal diseases, the effect of repetitive intravitreal (IV) anti-VEGF injections on CN is not known. METHODS: Retrospective case-control study. CN parameters were compared between eyes in 39 individuals who received anti-VEGF injections in one eye only. Next, we compared CN parameters between 50 eyes of 50 individuals with a history of IV anti-VEGF injections and 80 eyes of 80 individuals without a history of injection. In vivo confocal microscopic examination was conducted using the ConfoScan 4. Images were analyzed by the Corneal Nerve Analysis tool. Paired and independent t test methodologies were used to compare nerve parameters, and multivariable linear regression analysis was performed to control for potential confounders. RESULTS: In 39 patients (own controls), eyes with a history of IV injection had lower CN length density, total length, nerve fibers, bifurcations, and branches (P < 0.005) compared to the fellow eyes without injection. Similar findings were seen in the eyes of 50 individuals with a history of injection compared to 80 individuals without injection. A history of IV injections and ethnicity remained significantly associated with the CN length density and explained 32% of the variability (R = 0.56). CONCLUSIONS: We found decreased CN parameters in eyes with a history of anti-VEGF injections compared to eyes without such a history.