Eye exams may predict Alzheimer’s disease, Duke study finds

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A study from the Duke Eye Center suggests that the loss of blood vessels in the retina could signal Alzheimer’s disease, paving the way for an eye exam to serve as a non-invasive method for early detection of this brain disorder.

Findings from the Duke Eye Center Study

The research, published in the journal Ophthalmology Retina, involved over 200 people. In the eyes of healthy individuals, microscopic blood vessels form a dense web at the back of the eye inside the retina.

However, in the eyes of 39 people with Alzheimer’s disease, this web was less dense and even sparse in some places.

The differences in density remained statistically significant even after researchers controlled for factors such as age, sex, and level of education.

The study’s senior author, Sharon Fekrat, M.D., a Duke ophthalmologist and retinal surgeon, explained that they’re measuring blood vessels not visible during a regular eye exam using a relatively new noninvasive technology that takes high-resolution images of tiny blood vessels within the retina in just a few minutes.

Early Detection and Monitoring

Fekrat proposed that these changes in blood vessel density in the retina might reflect what’s happening in the tiny blood vessels in the brain, potentially before any changes in cognition are detectable.

The study identified differences in the retinas of those with Alzheimer’s disease when compared to healthy individuals and those with mild cognitive impairment, which is often a precursor to Alzheimer’s disease.

The Role of Optical Coherence Tomography Angiography (OCTA)

The Duke study used a noninvasive technology called optical coherence tomography angiography (OCTA).

OCTA machines use light waves to reveal blood flow in every layer of the retina, potentially capable of revealing changes in tiny capillaries—most less than half the width of a human hair—before blood vessel changes show up on a brain scan such as an MRI or cerebral angiogram.

These brain study techniques are invasive and costly.

Implications and Future Goals

With nearly 6 million Americans living with Alzheimer’s disease and no viable treatments or noninvasive tools for early diagnosis, this study’s findings could be significant.

The goal is to use this technology to detect Alzheimer’s early, before memory loss symptoms become evident, and to monitor these changes over time in participants of clinical trials studying new Alzheimer’s treatments, Fekrat said.

If you care about brain health, please read studies about vitamin D deficiency linked to Alzheimer’s and vascular dementia, and higher magnesium intake could help benefit brain health.

For more information about brain health, please see recent studies about antioxidants that could help reduce dementia risk, and coconut oil could help improve cognitive function in Alzheimer’s.

The study was published in Ophthalmology Retina.

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