Multimodal Retinal Imaging in Asymptomatic APOE ε4 Carriers, APOE ε4 Noncarriers, and Alzheimer's Disease

APOE ε4 carriers generally did not have significant differences in retinal microvasculature compared to AD, but showed differences compared to ε4 noncarriers, which may indicate that ε4 carriers have begun to show biomarker signs of AD without clinical symptoms. Peripapillary CPD was significantly higher in AD vs APOE ε4 carriers, which may be due to imaging time point during disease course. Longitudinal studies may better elucidate the role of these potential biomarkers along the AD spectrum.