Next time you’re checking your patient’s retinal health, you might want to see what’s going on with their brain, too. The width of retinal blood vessels may indicate brain health and cognitive function long before dementia or other deficits present themselves, according to a study in Psychological Science.

Because retinal blood vessels share similar size, structure and function with the blood vessels in the brain, researchers used digital retinal imaging to investigate vascular conditions in the brain. Psychological scientists at Duke University examined data from more than 1,000 people, and found that patients with wider retinal venules were associated with lower IQ scores, even after accounting for various health, lifestyle and environmental risk factors. In addition, subjects with wider retinal venules also showed evidence of general cognitive deficits, with lower scores on numerous measures of neuropsychological functioning.

The researchers suggest that digital retinal imaging may expand beyond eye care and serve as an investigative tool for psychological scientists studying the link between intelligence and health across the lifespan.

Shaley I, Moffitt TE, Wong TY, et al. Retinal vessel caliber and lifelong neuropsychological functioning: retinal imaging as an investigative tool for cognitive epidemiology. Psychol Sci. 2013 May 15.