Abstract
Purpose :
Geographic atrophy (GA) involvement in the foveal center has been associated with decreased visual acuity and quality of life. We aimed to quantify the time for atrophic lesions to reach the foveal center based on GA growth rate.
Methods :
This study included 718 eyes from 582 participants enrolled in the Age-Related Eye Disease Study 2 with at least 2 visits of GA area measurements, without foveal involvement at baseline or neovascularization at any visit. GA growth rate (mm/yr) was calculated using the difference in square root transformed GA area between the last and first visit divided by the time interval. Kaplan-Meier curves were used to calculate the median time required for GA to reach the foveal center (survival time), and the Cox proportional hazards model was used to investigate the effect of covariates. The output of the multivariable Cox model was used to generate counterfactual, confounder-adjusted survival curves, where GA growth rate was set between 0.05 and 1 mm/yr.
Results :
321 (45%) of non-central GA eyes progressed to involvement of the foveal center. Median baseline distance from GA lesion edge to foveal center was 461 μm. Median survival time was 3.5 years. In the Cox model (Table 1), a higher baseline GA distance to foveal center was associated with a decreased risk of foveal center involvement. Higher age, baseline GA area, and GA growth rate were associated with an increased risk of center involvement, while number of GA lesions (configuration) was not significantly associated. In the counterfactual survival analysis, a 0.1 mm/yr decrease in GA growth rate was associated with a 0.29 year delay in the median time for GA to reach the foveal center. The results were consistent with a survival analysis stratified by GA growth rate (Figure 1).
Conclusions :
Closer baseline GA proximity to foveal center, faster GA growth rate, higher baseline GA area, and older age increased the risk of foveal GA involvement. A 0.1 mm/yr decrease in GA growth rate is associated with an increase in median time to foveal involvement by 0.29 years.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.