Damage to the retina may provide an early warning sign of increased risk for stroke and dementia and early death, providing time for early intervention, new research suggests. "Impaired microvascular brain health is a rising public-health concern associated with stroke and dementia. There is no screening tool for preclinical risk stratification and really no direct clinical imaging tool for microvascular disease of the brain," Dr. Michelle Lin of Mayo Clinic Jacksonville, in Florida, said in presenting her findings at the American Stroke Association International Stroke Conference (ISC) 2021. "The retina is a window into the brain. Retinal imaging is fast, portable and low-cost and allows direct visualization of small vessels and neuronal tissue and we hypothesized that retinal features may serve as biomarkers for microvascular brain health," said Dr. Lin. She and her colleagues examined the association of retinopathy with stroke, dementia and the risk of death in adults participating in annual U.S. National Health and Nutrition Examination Surveys (NHANES) between 2005 and 2008. During those years, participants provided information on medical history and health behaviors and had a retinal scan to look for signs of retinopathy. Among more than 5,500 adults (mean age, 56 years), 13% had retinopathy and 87% had no evidence of retinopathy. Factors associated with retinopathy were older age, Black race, high school education or less and low socioeconomic status. Individuals with retinopathy were more likely to have vascular risk factors including hypertension, diabetes, dyslipidemia, heart disease and chronic kidney disease. There was no difference in smoking history between groups. After adjusting for vascular risk factors and demographics, retinopathy was associated with a significantly increased risk of dementia (odds ratio, 1.5; 95% confidence interval, 1.1 to 2.1) and a non-significant increase in stroke risk (OR, 1.6; 95% CI, 0.95 to 2.7), Dr. Lin reported. In addition, individuals with retinopathy were more likely to die within the next 10 years, with each increase in retinopathy severity conferring a higher risk. "There was a dose dependent response to the risk of mortality," Dr. Lin said, with a hazard ratio of 1.5 (95% CI, 1.1 to 2.0) for mild grade-1 retinopathy to a hazard ratio of 3.4 (95% CI, 0.5 to 25) for those with grade-3 proliferative retinopathy (P for trend= 0.021). The results, said Dr. Lin, suggest that the retina "may serve as a tissue biomarker in intervention trials for cerebrovascular and neurodegenerative diseases." Offering perspective on this research, Dr. Daniel Lackland of the Medical University of South Carolina in Charleston noted that the assessment of retinopathy is "very important" and this study suggests using this to look at stroke risk and adding retinopathy to other stroke risk factors. "The assessment of retinopathy is relatively simple to do and it fits into that mode of telehealth where we would be able to do things at a distance, maybe even through a phone, and then we could work on strategies for preventing a stroke if a person seems to have a high risk for stroke," Dr. Lackland said in a conference podcast. The study was funded by the National Center for Advancing Translational Sciences of the National Institutes of Health. —Megan Brooks Source
