Rates of RNFL Thinning in Patients with Suspected or Confirmed Glaucoma Receiving Unilateral Intravitreal Injections for Exudative AMD

Abstract

This study evaluated whether the rate of retinal nerve fiber layer (RNFL) thinning is faster in eyes receiving intravitreal injections than in fellow uninjected eyes among patients suspected of having or confirmed to have glaucoma and exudative age-related macular degeneration (AMD). Retrospective comparative cohort study. Patients with a diagnosis of unilateral exudative AMD and confirmed to have or suspected of having glaucoma in both eyes receiving unilateral intravitreal injections were identified. Those with ≥3 RNFL optical coherence tomography scans and ≥6 injections were included in the study. Rates of RNFL thinning in the injected eye versus the uninjected eye were estimated using linear mixed models. The main outcome measurement was the differences in rates of RNFL thinning in the injected versus the fellow uninjected eye. The effects of postinjection elevation of intraocular pressure (IOP), injection frequency, and number of injections were also evaluated. A total of 53 patients met the inclusion criteria, receiving 26.4 ± 15.9 intravitreal injections. The average rate of RNFL thinning in uninjected eyes was-0.620μm/year (P= .029). Injected eyes had an additional incremental loss of-0.385μm/year, but this value was not statistically significant (95% confidence interval [CI]:-1.147 to 0.379μm/year; P= .324). Subgroup analysis with only glaucoma patients (n= 33) also demonstrated a nonsignificant effect of injections (-0.568μm/year; 95% CI:-1.454 to 0.319μm/year; P= .212). Postinjection IOP elevation, injection frequency, and total number of injections were not associated with faster RNFL loss. Among exudative AMD patients with glaucoma or suspected of having glaucoma, the rate of RNFL thinning in eyes receiving intravitreal injections did not significantly differ from that of fellow uninjected eyes.