Abstract
Purpose :
To understand the correlation between OCT-defined lesions such as nascent geographic atrophy (nGA), incomplete retinal pigment epithelium and outer retinal atrophy (iRORA), and complete RORA (cRORA) by mapping them to features on fundus autofluorescence (FAF) and color fundus photography (FP). The study also monitors the evolution of these lesions over a five-year period using multimodal imaging.
Methods :
Participants from the Age-Related Eye Disease Study 2 (AREDS2) at University of Wisconsin were enrolled with exclusion of neovascular AMD and poor-quality images. OCT scans were graded using Classification of Atrophy Meeting (CAM) guidelines for nGA, iRORA and cRORA. Image registration enabled precise mapping of OCT lesions to the corresponding regions on FAF and FP. FAF was graded for hypo/hyper FAF in the corresponding area of nGA/iRORA/cRORA, while FP was graded for drusen, pigment abnormalities, and GA. The same regions of interest were evaluated after 5 years.
Results :
Of 73 eyes with intermediate AMD evaluated at baseline, 26 nGA, 42 iRORA and 89 cRORA lesions were detected. nGA and iRORA lesions had a similar mapping, with hypoFAF observed in 54.8%- 61.5%. With FP, drusen with pigment changes was seen in 27% - 36% and without pigment changes in 38%-50% of lesions. cRORA strongly correlated with hypoFAF in 98.9% and was associated with GA in 49% of lesions, while the remainder displayed drusen in 31% and pigment changes in 19%. Fading drusen were the most common type of drusen seen with all 3 lesions (42 %- 58%).
Among 21 eyes with 5-year follow-up, 4 (19%) of eyes with iRORA or nGA at baseline developed neovascular AMD and were excluded. Of the remaining 17 eyes with 37 precursor lesions, 70% converted to cRORA at year 5. HypoFAF rates changed from 60% to 86.6% with nGA lesions and 40.9% to 77.2% with iRORA lesions. All cRORA lesions developed GA by 5 years. With FP, GA developed in 46.7% of nGA lesions, 36.4% with iRORA and 100% with cRORA.
Conclusions :
Using multimodal comparison, we showed that nGA and iRORA typically represented earlier stages in the AMD continuum, often preceding the clinical manifestation of geographic atrophy (GA). These findings underscore the value of multimodal imaging in identifying eyes at risk of GA progression.
This abstract was presented at the 2024 ARVO Imaging in the Eye Conference, held in Seattle, WA, May 4, 2024.