Longitudinal Analysis of the Retina and Choroid in Cognitively Normal Individuals at Higher Genetic Risk of Alzheimer Disease

Purpose: To assess the baseline differences and longitudinal rate of change in retinal and choroidal imaging parameters between apolipoprotein 64 (APOE 64) carriers and noncarriers with normal cognition. Design: Prospective study. Subjects: Four hundred thirteen eyes of 218 individuals with normal cognition aged > 55 years with known APOE status (98 APOE 64 carriers and 120 noncarriers). The exclusion criteria included diabetes mellitus, uncontrolled hypertension, glaucoma, and vitreoretinal or neurodegenerative disease. Methods: OCT and OCT angiography (OCTA) were performed at baseline and 2 years (Zeiss Cirrus HD-OCT 5000 with AngioPlex; Zeiss Meditec). The groups were compared using sex-and age-adjusted generalized estimating equations. Main Outcome Measures: OCT parameters: retinal nerve fiber layer thickness, macular ganglion cellinner plexiform layer thickness, central subfield thickness (CST), and choroidal vascularity index. OCT angiography parameters: foveal avascular zone area, perfusion density (PD), vessel density, peripapillary capillary PD (CPD), and capillary flux index (CFI). The rate of change per year was calculated. Results: At the baseline, the APOE 64 carriers had lower CST (P = 0.018), PD in the 6-mm ETDRS circle (P = 0.049), and temporal CFI (P = 0.047). Seventy-one APOE 64 carriers and 78 noncarriers returned at 2 years; at follow-up, the 6-mm ETDRS circle (P = 0.05) and outer ring (P = 0.049) showed lower PD in the APOE 64 carriers, with no differences in the rates of change between the groups (all P > 0.05). Conclusions: There was exploratory evidence of differences in the CST, PD, and peripapillary CFI between the APOE 64 carriers and noncarriers with normal cognition. Larger and longer-term studies may help further elucidate the potential prognostic value of these findings. (C) 2022 by the American Academy of Ophthalmology

Automated summary

The purpose of this study was to assess the baseline differences and longitudinal rate of change in retinal and choroidal imaging parameters between APOE 64 carriers and noncarriers with normal cognition. The results showed that there were differences in certain parameters between the APOE 64 carriers and noncarriers, but no significant differences in the rates of change between the groups during the follow-up. These findings provide preliminary evidence for further investigating the prognostic value of these parameters.