Although intravitreal anti-vascular endothelial growth factor (VEGF) can help stave off new vessel proliferation in conditions such as age-related macular degeneration and diabetic retinopathy, it may also come with unforeseen sequelae according to a new study. Researchers from Bascom Palmer Eye Institute in Miami and the Illinois Eye and Ear Infirmary at the University of Illinois College of Medicine in Chicago teamed up to explore anti-VEGF’s role in corneal nerve function and discovered repeat injections can negatively impact the corneal nerves.

The team used in vivo confocal microscopy to compare corneal nerve parameters of 39 patients who received anti-VEGF injections in one eye only, with their untreated eye serving as the control. They also compared 50 eyes with a history of intravitreal anti-VEGF injections with 80 controls without a history of injection.

The patients with unilateral anti-VEGF injections had lower corneal nerve length density, total length, nerve fibers, bifurcations and branches compared with their untreated eyes. The same was true for the 50 eyes with a history of injections compared with the 80 controls. “A history of [intravitreal] injections and ethnicity remained significantly associated with the [corneal nerve] length density and explained 32% of the variability,” the study says.

The study further discovered the type of injection—bevacizumab only, bevacizumab plus aflibercept or aflibercept only—had no bearing on the corneal nerve parameters, and neither did the number of injections, the time from the first injection to the scan or the time from the last injection to the scan.

While none of the patients receiving anti-VEGF injections had notable corneal abnormalities such as keratolysis and corneal edema, eye care providers should be aware of these study findings and be alert to the possible long-term effects of repeated intravitreal anti-VEGF injections, the study concludes.