Abstract
Purpose :
To compare OCT features of age-related macular degeneration (AMD) including nascent geographic atrophy (nGA), incomplete and complete retinal pigment epithelium and outer retinal atrophy (iRORA and cRORA) to corresponding regions of interest on fundus autofluorescence (FAF) and fundus photos (FP) at baseline and follow progression over 5 years.
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 iRORA/cRORA/nGA, while FP was graded for drusen, pigment abnormalities, and GA. The same regions of interest were evaluated after 5 years.
Results :
At baseline, 73 eyes (69 participants) were included. OCT grading identified 14 nGA, 30 iRORA, 12 both nGA/iRORA, and 89 cRORA lesions, with varying lesion counts within each eye. The table below identifies the features on FAF and FP corresponding to each lesion.
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 29 precursor lesions, 66% converted to cRORA at year 5. Breakdown of lesion mapping showed 57% of nGA, 57% of iRORA, and 88% of both nGA/iRORA at baseline converted to cRORA. By year 5, all cRORA lesions observed at baseline had progressed to GA on FP. Additionally, conversion to GA was noted in 43% of eyes with baseline nGA, 29% with iRORA, and 50% with both nGA and iRORA lesions.
Conclusions :
Our study shows that mapping OCT lesions to FAF and FP regions can provide insights into AMD progression. The multimodal image mapping study shows that nGA represents a stage after drusen but before pigment changes, whereas iRORA includes drusen and pigment changes. cRORA appears to represent all features including drusen, pigment changes, and GA. Over 5 years, both nGA and iRORA had similar conversion rates to cRORA. Conversion to GA on FP was higher with nGA than iRORA. In contrast, cRORA consistently progressed to GA on FP, suggesting it as a potential outcome variable in treatment trials.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.