Researchers of Duke University found that using ultrasensitive scanning technique they can identify the signs of Alzheimer’s disease and brain health through an eye check-up.
The study was published in the journal Ophthalmology Retina on March 11, 2019.
Alzheimer’s disease is a chronic neurodegenerative disease, that gradually worsen over time. This disease leads to memory loss and affects one’s thinking skills. There is no successful treatment available for this in the market, nor there is any tool for its early diagnose.
The team of researchers has done comparative studies to study the retinas of Alzheimer patients in comparison to those people who had mild cognitive impairment.
For this research, the researchers have used a non-invasive technology called optical coherence tomography angiography (OCTA) to detect the sign of Alzheimer. This technology uses light waves that show the blood flow in every layer of the retina. OCTA can track the changes in the retina which signal the obstacles in the brain activity, such as thinning of retinal nerves layers.
The research was conducted on more than 200 people. Out of these 133 participants were in a control group, who had healthy brains. In this group, it has been observed that microscopic blood vessels form a dense web at the back of an eye inside the retina. Whereas, 39 people who had Alzheimer’s disease, have shown the web was less dense and even scattered in places.
As a result, researchers have found that Alzheimer patients show differences in retinas when compared to the retinas of people with healthy brains.
According to Dilraj S. Grewal, a Duke ophthalmologist and retinal surgeon and a lead author on the study, said, “We know that there are changes that occur in the brain in the small blood vessels in people with Alzheimer’s disease, and because the retina is an extension of the brain, we wanted to investigate whether these changes could be detected in the retina using a new technology that is less invasive and easy to obtain.”
Sharon Fekrat, the study’s senior author, and Duke ophthalmologist and retinal surgeon, said, “We’re measuring blood vessels that can’t be seen during a regular eye exam and we’re doing that with relatively new noninvasive technology that takes high-resolution images of very small blood vessels within the retina in just a few minutes.”
She added, “It’s possible that these changes in blood vessel density in the retina could mirror what’s going on in the tiny blood vessels in the brain, perhaps before we are able to detect any changes in cognition.”
Alzheimer’s disease is the most common type of dementia. Alzheimer’s disease made it to 60-70% of the total cases of dementia. About 50 million people (5 crore) around the world suffers from dementia. Every year 10 million (1 crore) new cases of this disease are recorded worldwide.
According to the researchers, OCTA scan technology can even diagnose the tiniest capillaries, which are in the width, less than half of human hair. This technology is better than MRI or cerebral angiogram which can only diagnose larger blood vessels. Those technologies are invasive and even costly to study.