From: Duke University
Department of Psychology & Neuroscience, Institute for Genome Sciences & Policy 2020 West Main Street, Suite 201 Box 104410 Durham, North Carolina 27708TITLE: Retinal Vessel Caliber and Lifelong Neuropsychological Functioning An international research team from the USA, UK, Singapore and New Zealand reports that the size of the blood vessels in the back of the eye can indicate the health of the brain of people approaching midlife (age 38 years), years before age-related declines in brain functioning. PUBLICATION SOURCE: Psychological Science, advance online publication date, May 2013. BACKGROUND:
- Young people who score low on IQ tests, tend to be at higher risk for diseases in later life, and even tend to die younger.
- One plausible explanation for this link is that intelligence tests assess brain health.
- Digital retinal imaging is a relatively new and non-invasive method to visualize the small blood vessels in the retina, at the back of the eye. The small vessels in the eye may reflect the conditions of the vessels inside the brain because both eye and brain vessels share similar size, structure and function. Thus, retinal imaging can provide a window to study the health of the brain in living humans.
- We studied the link between retinal vessel width and intelligence tests scores in the representative Dunedin birth cohort of 1000 New Zealanders born in 1972-73, and followed for 38 years with repeated assessments.
- Using a digital fundus camera, which can photograph the interior surface of the eye, we were able to assess the size of the small blood-vessels in the retina, namely, the arterioles and venules (the small branches of the arteries and veins). We also administered intelligence tests in childhood and adulthood.
- We found that study members who presented with wider venules had poorer intelligence tests scores at midlife (age 38 years). This finding held up independently of potential factors that may explain this link, such as low socio-economic status, smoking, or diabetes.
- Moreover, wider venules in the eye were linked with lower childhood IQ that had been tested 25 years earlier.