RetinaAge / fundus-based age clock

RetinaAge is a biological-age clock derived from fundus photographs of the retina, using deep-learning models trained to predict chronological age from the vascular and neural features of the optic disc, fovea, and retinal vasculature. Published by Zhu and colleagues (2023, British Journal of Ophthalmology), the model was trained and validated on roughly 19,200 fundus images from 11,052 healthy UK Biobank participants (drawn from a wider dataset of ~80,000 images used for downstream mortality analysis); the gap between predicted retinal age and chronological age independently predicted all-cause mortality and cardiovascular events in UK Biobank participants. Because the retina shares embryological origin with the central nervous system and is the only site where microvasculature can be imaged non-invasively, it offers a clinically practical window onto systemic and neural vascular aging.