Window of Exclusivity
How retinal capillary density, as measured by OCT-A, could be used as a surrogate for Alzheimer’s disease progression – or even diagnosis
Geoffrey Potjewyd | | Quick Read
If the brain were a nightclub, it would be filled with A-list celebrities – and you’d probably be refused entry. The only way to get an idea of what’s going on (without resorting to extreme measures) would be to peek through the windows. By using OCT angiography to look through the eyes, it is possible to learn how certain Alzheimer’s disease (AD) risk genes are affecting the retinal vasculature – as a surrogate measure of how the disease is progressing.
Researchers from University of California San Francisco Memory and Aging Center and Johns Hopkins Wilmer Eye Institute in Baltimore, Maryland, US, have correlated retinal capillary density to different stages of AD in people carrying the APOE ε4 genotype (1). Specifically, the team collected OCT angiography data, cognitive tests, and brain imaging to build a statistical model that measures associations between pathological phenotypes, including retinal vasculature density, and genotype. This enables investigation of the brain vasculature that can illuminate the pathogenesis of APOE ε4, and other AD mutations, with the ease of an eye test.
Ultimately, the findings showed that lower retinal capillary densities occur in early disease in cognitively normal APOE ε4 gene carriers, potentially pointing the way to an earlier biomarker for at-risk individuals.
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- FM Elahi et al., Alzheimers Dement (Amst), 13, e12181 (2021). PMID: 34013017.