Association between choroidal microvasculature in the eye and Alzheimer's disease risk in cognitively healthy mid-life adults: A pilot study

INTRODUCTION: We explored associations between measurements of the ocular choroid microvasculature and Alzheimer's disease (AD) risk.

METHODS: We measured the choroidal vasculature appearing in optical coherence tomography (OCT) scans of 69 healthy, mid-life individuals in the PREVENT Dementia cohort. The cohort was prospectively split into low-, medium-, and high-risk groups based on the presence of known risk factors (apolipoprotein E [ APOE] ε4 genotype and family history of dementia [FH]). We used ordinal logistic regression to test for cross-sectional associations between choroidal measurements and AD risk.

RESULTS: Choroidal vasculature was progressively larger between ordinal risk groups, and significantly associated with risk group prediction. APOE ε4 carriers had thicker choroids and larger vascularity compared to non-carriers. Similar trends were observed for those with a FH.

DISCUSSIONS: Our results suggest a potential link between the choroidal vasculature and AD risk. However, these exploratory findings should be replicated in a larger sample.

HIGHLIGHTS: Ocular choroidal microvasculature is of interest in relation to neurodegeneration due to its autonomic response to systemic, pathophysiological change.Choroidal changes in the prodromal stage of Alzheimer's disease (AD) are unexplored.The PREVENT Dementia cohort offers a unique, non-invasive study of the microvasculature in mid-life individuals at increased risk for developing AD.Significantly increased ocular choroidal vasculature was associated with increased risk (apolipoprotein E carrier and/or family history of dementia) for AD.These exploratory results suggest a potential association between the ocular choroidal vasculature and AD risk. However, findings should be replicated in a larger sample.