A new study from the University of Otago has found that the health of our eyes might provide early warning signs of dementia.
Researchers discovered that the tiny blood vessels at the back of the eye, known as the retinal microvasculature, can show changes that are linked to a higher risk of developing dementia.
Dr. Ashleigh Barrett-Young from Otago’s Department of Psychology, who co-led the study, said the findings help build on earlier research. Together, this work is helping scientists “put together pieces of a puzzle” to identify early signs of dementia.
Although the research is still in the early stages and not ready to be used in everyday healthcare, scientists are hopeful about what this could mean in the future. Treatments for Alzheimer’s disease and other types of dementia tend to work best when started early, so spotting the signs before symptoms appear could make a big difference.
Currently, identifying people who are at risk is difficult. Common cognitive tests may not pick up changes in the brain during the early stages of the disease. Other tests, like brain scans using MRI or PET imaging, are costly and not always available. That’s why researchers are looking for simpler, more affordable tools.
The retina, which is the light-sensitive layer at the back of the eye, is directly connected to the brain. Scientists believe that changes in the brain caused by Alzheimer’s may also be visible in the retina, making eye scans a promising way to detect dementia early.
This study was co-led by Dr. Aaron Reuben of the University of Virginia and is part of the long-running Dunedin Multidisciplinary Health and Development Study, New Zealand’s most in-depth health and development research project.
Researchers analyzed eye scans taken when participants were 45 years old. They found that people with narrower arterioles (small arteries), wider venules (small veins), and thinner retinal nerve fiber layers (which help transmit visual signals to the brain) had a greater risk of developing dementia.
Dr. Barrett-Young said she was surprised that changes in the venules were linked to many signs of Alzheimer’s disease. This may mean that these veins could become a valuable focus for future dementia testing.
Despite the exciting results, Dr. Barrett-Young cautions that this is still early research. “We can’t predict your future by looking at an eye scan—not yet,” she said. “But in the future, we hope that AI tools will help us use eye scans to give people insights into their brain health.”
The study was published in the Journal of Alzheimer’s Disease and represents another example of Otago’s collaboration with researchers around the world.
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The study is published in Journal of Alzheimer’s Disease.
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