Thicker macula in asymptomatic APOE Ɛ4 middle-aged adults at high AD risk.

Introduction: We compared retinal layers' thickness between apolipoprotein E ( APOE ) Ɛ4 carriers and non-carriers in a cohort of cognitively normal middle-aged adults enriched for Alzheimer's disease (AD) risk.
Methods: Participants (N = 245) underwent spectral domain optical coherence tomography. Multivariate analyses of covariance adjusting for age, sex, education, and best corrected vision acuity was used to compare retinal thickness between APOE groups.
Results: Participants' mean age was 59.60 (standard deviation = 6.42) with 66.4% women and 32.2% APOE Ɛ4 carriers. Greater macular full thickness was observed in APOE Ɛ4 carriers compared to non-carriers ( P  = .017), reaching statistical significance for the inner and outer nasal ( P  = .009 and P  = .005, respectively), inner superior ( P  = .041), and inner and outer inferior ( P  = .013 and P  = .033, respectively) sectors. The differences between APOE groups were mainly driven by the ganglion cell layer ( P  < .05) and the inner plexiform layer ( P  < .05).
Discussion: A thicker macula is observed already in midlife asymptomatic APOE Ɛ4 carriers at high AD risk.
Competing Interests: The authors have no conflicts of interest to declare.
(© 2021 The Authors. Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring published by Wiley Periodicals, LLC on behalf of Alzheimer's Association.)