Purpose
To quantify the size and growth rate of geographic atrophy (GA) during anti-VEGF therapy of choroidal neovascularization (CNV).
Methods
1185 CATT participants were randomly assigned to ranibizumab or bevacizumab treatment and to a 2-year monthly or PRN injection dosing regimen, or monthly injections for 1 year and PRN injections the following year. 242 participants had GA visible on digital color photographs (CP) or fluorescein angiograms (FA) at baseline, 1 or 2 years. Total area of all GA lesions was measured by two graders masked to treatment using Image J; differences were adjudicated. Annual change in the square root of the total area of GA was the measure of growth. Multivariate linear mixed models including baseline demographic, treatment, and ocular characteristics on CP/FA and OCT as candidate risk factors were used to estimate adjusted growth rates (aGR) and 95% confidence intervals (CIs).
Results
Median (interquartile range) area of incident GA among 156 eyes was 1.15 mm2 (0.48, 2.75). The area of incident GA was not significantly different between eyes treated with ranibizumab (1.29 mm2 [0.56, 2.98]) and bevacizumab (0.91 mm2 [0.43, 2.28]; p=0.09), or between monthly (1.03 mm2 [0.47, 2.77]) and PRN (1.21 mm2 [0.51, 2.56]; p=0.53) dosing. The overall growth rate among 113 eyes with incident lesions was 0.41 mm/yr (0.33, 0.49). The aGR was 0.46 mm/yr [0.32, 0.60] for ranibizumab and 0.37 mm/yr [0.21, 0.53] for bevacizumab (p=0.22); and 0.38 mm/yr [0.23, 0.54] for monthly and 0.45 mm/yr [0.29, 0.61] for PRN (p=0.47). For 81 eyes with GA present at baseline (prevalent), the overall growth rate was 0.45 mm/yr [0.37, 0.45]. The aGR was 0.52 mm/yr [0.41, 0.63] for ranibizumab and 0.37 mm/yr [0.25, 0.49] for bevacizumab (p=0.04). The aGR was 0.48 mm/yr [0.37, 0.60] for monthly and 0.41 mm/yr [029, 0.52] for PRN (p=0.28). The aGR of GA was less for eyes with occult CNV than for eyes with minimal or predominantly classic CNV for both incident (Table 1) and prevalent GA (Table 2). GA in the fellow eye was associated with greater growth rate for incident GA, but not prevalent GA.
Conclusions
Previous analyses of CATT data demonstrated greater incidence of GA in ranibizumab treated eyes compared with bevacizumab. These analyses demonstrate greater GA growth rate in eyes treated with ranibizumab, suggesting that ranibizumab may have a greater effect on GA than bevacizumab.
Keywords: 412 age-related macular degeneration •
466 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials •
464 clinical (human) or epidemiologic studies: risk factor assessment