Abstract
Purpose :
Retinal β-amyloid (Aβ) deposits have been identified by histological examination in both Alzheimer’s disease (AD) and age-related macular degeneration (AMD). In vivo retinal Aβ has previously been identified in AD. In this study, we identified and measured retinal Aβ “hot spots” in vivo in participants with dry AMD and Alzheimer’s disease. These deposits can be detected in vivo using oral curcumin, which binds to Aβ deposits, as a fluorescent label in conjunction with ocular coherence tomography with BluePeak autofluorescence (OCT-BAF).
Methods :
AMD (n=24), AD (n=5), and control (n=6) participants were recruited from the office of Zaparackas and Knepper in Chicago, Illinois and enrolled in clinical trial NCT05062486. OCT-BAF imaging (Heidelberg Spectralis) and a customized proprietary artificial intelligence program was used to identify and visualize retinal Aβ. Images were taken before and after participants took oral curcumin for 7-14 days at a dose of 2.6 g/day. Retinal Aβ hot spots were defined as spots of retinal fluorescence after subtracting baseline images. A composite score (retinal amyloid index, RAI) was used to incorporate the number of individual spots, total spot area, and fluorescence intensity.
Results :
Participants with AMD had a significantly higher number of hot spots (36.2 vs. 21.3, p=0.002) and a higher RAI (34.3 vs. 20.98, p=0.002) compared with controls. Participants with AD had a significantly higher number of hot spots (49.4) compared with both controls (p<0.01) and AMD (p<0.05) and a significantly higher RAI (63.4) compared with both controls (p<0.0001) and AMD (p<0.05).
Conclusions :
Retinal Aβ hot spots are increased in AMD and AD. The detection of retinal Aβ hot spots in vivo suggests novel therapeutic targets in AMD and AD. Hot spots can be used as an endpoint measured longitudinally in clinical trials. Hot spots are a new target for the treatment of AMD and AD.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.