Abstract
Purpose :
To measure disease progression of geographic atrophy (GA) secondary to age-related macular degeneration (AMD) in untreated fellow eyes in bilateral GA patients from two large phase III clinical studies using automated AI-based quantifications of the outer retina on optical coherence tomography (OCT).
Methods :
Fellow eyes presenting with GA from two phase III randomized controlled studies (OAKS, NCT03525613 and DERBY, NCT03525600) were analyzed. Eyes showing signs of macular neovascularization were excluded from the analysis. Photoreceptor (PR) and retinal pigment epithelium (RPE) loss were quantified on Spectralis OCT using fully automated AI-based algorithms. Longitudinal PR/RPE loss ratios were calculated and investigated over time. To reduce the influence of baseline lesion size, PR and RPE loss growth rates were calculated for each study year after performing a square root transformation and were assessed in mm/year.
Results :
753 fellow eyes from OAKS and DERBY combined were included. 369 eyes presented with and 384 eyes without subfoveal atrophy, respectively. At baseline, mean (SD) area of PR loss was similar between eyes with and without subfoveal GA with 11.25 (6.29) vs. 11.23 (5.85) mm2, respectively. Furthermore, no significant increase of PR loss could be observed between the two groups (p=0.079). Eyes without subfoveal GA at baseline had a significantly smaller mean RPE loss area (6.91 (4.6) vs 8.63 (4.86) mm2). PR/RPE loss ratios were consistently and significantly larger in patients without subfoveal GA for the complete study period of 24 months (p<0.001). Nonetheless, a convergence of PR/RPE loss ratios between eyes with and without subfoveal involvement can be observed as the PR/RPE loss ratio was significantly larger during the first study year compared to the second study year (p=0.01). This can be explained by a significantly faster progression (p<0.001) of RPE loss during the first (0.343 (0.328) vs 0.275 (0.188) mm/year (SD)) and second year (0.354 (0.276) vs. 0.257 (0.177) mm/year (SD)) in patients without subfoveal GA.
Conclusions :
Automated quantification of the outer retina layers with advanced OCT-based AI tools enables personalized patient monitoring of disease activity over time. PR/RPE loss ratios decrease in patients without subfoveal GA, suggesting decelerating RPE degeneration over time in this subgroup.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.