Retinal vascular perfusion is positively associated with cognitive measures of new learning, information processing, and executive function in African Americans

Abstract

Purpose : An estimated 55 million people live with dementia worldwide mainly due to Alzheimer’s disease and vascular dementias (e.g. cerebral small vessel disease). There is increasing interest in identifying novel tools for early detection of cognitive impairment. We investigated optical coherence tomography angiography (OCTA) based metrics of retinal capillary density and perfusion as a biomarker of cognitive function in asymptomatic, community-dwelling African Americans, who are at high risk of vascular dementia.

Methods : African American participants over the age of 40 without any history of cognitive impairment were recruited. In-clinic neurocognitive assessment was conducted using NIH Toolbox Cognitive Function Battery tests, including Fluid Cognition Composite (episodic memory, executive function, and information processing abilities), Oral Symbol Digit (simple processing speed), and Crystallized Cognition Composite (past learning) tests. 3x3 mm swept source OCTA images centered on the fovea were captured from both eyes. Quantitative measures of retinal vascular density (Vessel Area Density (VAD)) and perfusion (Vessel Area Flux (VAF)), were computed for both eyes and averaged. The relationship between the OCTA measures and cognitive function tests was evaluated using multiple linear regression analysis controlling for age, gender, and level of education.

Results : Ninety six participants were recruited (mean age, 66.4 ± 9.6 years; 31 male, 32.3%, Table 1). VAD and VAF were positively correlated with Fluid Cognition Composite (p = 0.02 and 0.005, respectively) and Oral Symbol Digit test scores (p = 0.0007 and 0.005, respectively; Fig 1) in the multivariable analyses. OCTA measures were not significantly correlated with Crystallized Cognition Composite score. Results were similar if analyses were limited to data from one eye per person.

Conclusions : OCTA-derived measures of retinal perfusion were correlated with cognitive measures of new learning, information processing, and executive function, but not with measures of past learning. Our results suggest that OCTA might be a useful additional tool for screening and early diagnosis of cognitive impairment.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.

 

 

Association of OCTA measures of retinal vessel area density (VAD) and vessel area flux (VAF), with NIH Toolbox cognitive measures.