Is width of blood vessels in eye tied with IQ, cognitive function?

Eyes are the windows of the soul, is the popular adage, but with technological advances they are rapidly becoming the mirror to our hearts, arteries and brain too.
According to a novel study, high-tech tests involving digital retinal imaging may be an indicator of neuro psychological health years before the onset of dementing diseases and other deficits.
High-resolution images of the retina at the back of the eye can reveal breaks or abnormalities in blood vessels that may co-relate with intelligence of the person.
Experts, theorize that the nerves that feed the brain could indicate if the person is suffering from diseases that affect cognition and memory, such as dementia.
Lead author of the study, psychological scientist Idan Shalev of Duke University stated, “Digital retinal imaging is a tool that is being used today mainly by eye doctors to study diseases of the eye. But our initial findings indicate that it may be a useful investigative tool for psychological scientists who want to study the link between intelligence and health across the lifespan.”
Study details
In a bid to examine the potential link between intelligence and brain health, the researchers conducted a study.
They analyzed data from participants enrolled in the Dunedin Multidisciplinary Health and Development Study, a longitudinal investigation of health and behavior involving over 1000 people born between April 1972 and March 1973 in Dunedin, New Zealand.
The analysis revealed people with wider retinal venules at age 38 was tied with lower IQ. This co-relation persisted, even after taking into account various risk factors such as health, lifestyle, and environmental aspects that might have played a role.
It was noted that people with wider retinal venules exhibited lower scores on various measures of neurospsychological functioning, including verbal comprehension, perceptual reasoning, working memory, and executive function.
In fact the data revealed that people who had wider venules at age 38 also had lower IQ as kids and teens.
Shaley stated, “It’s remarkable that venular caliber in the eye is related, however modestly, to mental test scores of individuals in their 30s, and even to IQ scores in childhood.”
He added, “Increasing knowledge about retinal vessels may enable scientists to develop better diagnosis and treatments to increase the levels of oxygen into the brain and by that, to prevent age-related worsening of cognitive abilities.”
The study is published in the journal Psychological Science.