Eye damage could predict dementia risk, new study finds

They say that eyes are the window to the soul, but they could also provide a glimpse into the future health of the over-60s. A new study has found that moderate to severe retinal damage could be a clue that individuals will have cognitive problems by the time they’re 80.

Scientists at John Hopkins University looked into the eye health of 60-year-olds as they aged. They discovered that the average cognitive and memory test scores for those with retinopathy dropped by 1.22 points over the course of 20 years. In comparison, the participants with good eye health declined by 0.91 points.

Dr Jennifer Deal, author of the research, said: “If our study results can be confirmed, differences in retinal integrity could provide reasonable estimates of how much small blood vessel damage in the brain is contributing to cognitive decline.”

Identifying patients who are at risk of cognitive conditions, such as Alzheimer’s disease and other forms of dementia, is vitally important. There is currently no cure for these neurodegenerative diseases, but treating them early can help to reduce the symptoms and help individuals live a more independent life for longer.

Dr Sara Imarisio, head of research at Alzheimer's Research UK, responded to the recent findings. She said that the eyes are a good way to see what is happening in the brain, which is well-protected and therefore hidden from view. Instead of expensive brain scans, eye tests can be used to gain information in a cheaper and non-invasive manner.

She added: “Exploring how our eyes can shed light on changes underway in the brain is an area that is attracting more and more research attention.”

While this latest research didn’t expressly explore the links between eye health and dementia, its findings associating changes in the retina and cognitive decline are significant. It paves the way for more studies to look at the connections and possibly implement new methods of diagnosis.

The long-running study asked 12,317 people to take thinking skills and memory tests. They were then asked to complete similar tests six years and 20 years later. The back of the eye was also photographed using a retinal camera at regular intervals to track any changes.

Some 11,692 of the test subjects had no indication of blood vessel-related retinal damage or retinopathy. A further 365 participants had mild signs of retinopathy and 256 individuals displayed moderate to severe damage to the retina.

Dr Deal said: “Problems with the small blood vessels in the brain are likely as important a factor in cognitive decline as problems with larger arteries, but we don't have the ability to take pictures of these small vessels with brain imaging.

“Because the blood vessels in the eye and the brain are so similar anatomically, we hypothesised that looking at the blood vessels in the eye would help us understand what was happening in the brain.”

According to the Alzheimer’s Society, someone in the UK will develop dementia every three minutes over the course of the next 12 months. That equates to 225,000 new sufferers, adding to the 850,000 people already living with the condition in this country.