Abstract
Purpose :
Inhibitors of vascular endothelial growth factor (anti-VEGF) are effective treatments for neovascular age-related macular degeneration (nAMD); but there is concern that treatment might increase the risk of geographic atrophy (GA). We compared treated nAMD eyes to fellow eyes without nAMD to assess whether the nAMD eyes had greater incidence and progression of GA and asymmetry in retinal location.
Methods :
Among 1185 patients with nAMD in the study eye enrolled in the Comparison of Age-related Macular Degeneration Treatments Trials (CATT), 1010 study eyes and 624 fellow eyes had no GA, no prior anti-VEGF treatment and no nAMD (fellow eyes only). Study eyes were treated with either ranibizumab or bevacizumab given monthly or as needed. Color photos and fluorescein angiograms were graded for presence, area, and location of GA. Kaplan-Meier curves and proportional hazards models (adjusted for age and sex) were used for comparing incidence. GA growth rates were calculated using a square root transformed area of GA in a linear mixed model. Symmetry of GA location between eyes was assessed with Kappa(K) by comparing sectors of the ETDRS grid for presence of GA.
Results :
The cumulative incidence of GA after 5 years was 37.5% (95% CI: 33.7-41.6%) vs. 23.2% (95% CI: 18.3-29.2%) between study and fellow eyes (p<0.001; Figure 1). The adjusted hazard ratio was 1.85 (95% CI 95: 1.49-2.31) (p<0.001). The mean total area of GA at first detection was 4.15 mm2 (95% CI: 3.39-4.90) in study eyes vs. 1.81 mm2 (95% CI: 1.32-2.30) in fellow eyes (p<0.0001). The mean GA growth rate per year was 0.39 mm (95% CI: 0.26-0.52) among 133 study eyes vs. 0.30 mm (95% CI: 0.25-0.35) in 23 fellow eyes (p = 0.14). GA location in bilaterally affected patients was no more symmetric than expected by chance (p-value <0.05 for Kappa [K=0.30] for only 1 sector).
Conclusions :
The risk of developing GA in study eyes during five-years of anti-VEGF therapy for nAMD was nearly twice as great as in untreated fellow eyes without nAMD and the average total area of GA at first detection was greater. GA Location was not symmetric. Mean growth rates between the two groups were similar. These findings are consistent with acceleration of GA development by nAMD treated with anti-VEGF.
This is a 2020 ARVO Annual Meeting abstract.