Effect of Anti-VEGF Therapy on RNFL Density of Glaucomatous Eyes
By Lynda Seminara
Selected By: Richard K. Parrish II, MD
American Journal of Ophthalmology, June 2021
Although treatment of neovascular age-related macular degeneration (AMD) with multiple anti-VEGF injections doesn’t appear to thin the retinal nerve fiber layer (RNFL) significantly, patients with confirmed or suspected glaucoma have been excluded from such research. It is plausible that glaucoma may worsen from elevations in intraocular pressure (IOP) that occur with intravitreal injections. However, findings of a retrospective study by Swaminathan et al. suggest that most patients with mild or moderate glaucoma can receive a moderate number of injections for AMD without the risk of accelerated RNFL thinning. Even though some patients with glaucoma will require IOP-lowering therapy before anti-VEGF injections, the authors do not endorse widespread use of preinjection procedures.
The study participants had neovascular AMD in one eye and confirmed or suspected glaucoma in both eyes. They had received at least three RNFL OCT scans and at least six intravitreal injections. The primary endpoint was the difference in rates of RNFL thinning between the injected and the fellow uninjected eye, as estimated by linear mixed models. Secondarily, the authors looked at injection frequency, total number of injections, and high postinjection IOP levels in relation to RNFL thinning.
Fifty-three patients (mean age, 79.0 years; 62.3% female; 92.4% White) met the criteria for inclusion. The mean number of intravitreal injections was 26.4 ± 15.9, at an average rate of 5.4 ± 2.5 injections per year. The average rate of RNFL thinning in untreated eyes was significant: ‒0.620 μm/year (p = .029). Among injected eyes, there was an additional (but insignificant) incremental loss of ‒0.385 μm/year. Over time, no association was observed between injection status and RNFL density data. In the subgroup of 33 patients with confirmed glaucoma, most of whom had mild or moderate disease, the rate of change in RNFL thinning of injected eyes was not significant (‒0.568 μm/year). Moreover, there was no meaningful relationship between any secondary endpoint and the rate of RNFL thinning.
Despite the promising findings of this study, the authors cautioned that a small number of patients will have progressive RNFL loss with intravitreal treatments.
The original article can be found here.