Associations of OCTA-based retinal microvascular markers with cognitive decline in an older adult biracial community sample: what can we learn from retinal imaging?

Abstract

Purpose : Accumulated vascular damage contributes to onset and progression of vascular dementia and possibly to Alzheimer’s disease. Here we evaluated the feasibility and utility of using retinal imaging of microvascular markers to identify older adults at risk of cognitive disease.

Methods : The Eye Determinants of Cognition (EyeDOC) study recruited a biracial population-based sample from two sites: Jackson, MS, and Washington Co, MD. From 2017 to 2019, optical coherence tomographic angiography (OCTA) was used to capture vessel density (VD) across vascular layers and foveal avascular zone (FAZ) area from a scan of the macula. Image quality was assessed by trained graders. A neurocognitive battery of 10 tests was administered at three time points from 2011 to 2019 and incident MCI/dementia cases were ascertained. Linear mixed effects models were used to evaluate associations of retinal vascular markers with cognitive factor score change over time.

Results : 976 older adults, mean age of 78.7 (± 4.4) years, 44% black, were imaged. Gradable images were obtained in 55% (535/976), with low signal strength (66%) and motion artifact (22%) the largest contributors to poor quality. Both worse presenting distance visual acuity (p<0.001) and worse contrast sensitivity (p=0.031) were associated with poor quality images. Among the 480 participants with high quality images and no clinically significant retinal pathology, no associations of VD in any vascular layer or FAZ with longitudinal changes in either global cognitive function or with incident MCI/dementia were found.

Conclusions : In this large biracial community sample of older adults, OCTA-based retinal vascular imaging biomarkers were not associated with cognitive decline, incident MCI or dementia. Challenges with obtaining high quality OCTA images in older community-dwelling adult populations may currently limit the feasibility and utility of OCTA-retinal markers for detecting risk of cognitive disease.

This is a 2021 ARVO Annual Meeting abstract.

 

Scatter plot of global cognitive function versus vessel density (VD) in the superficial vascular plexus (SVC), intermediate capillary plexus (ICP), and deep capillary plexus (DCP) in 480 older adults from Jackson, MS, and Washington Co, MD imaged in the EyeDOC study. Solid line is the Locally Weighted Scatterplot Smoothing (LOWESS) fit; broken line is the linear regression fit.