(CN) – A trip to the eye doctor may someday reveal Alzheimer’s disease before any symptoms manifest, according to a study published Monday in the journal Ophthalmology Retina.

Duke University researchers captured images of the eyes of over 200 people and discovered differences in the retinas of those with Alzheimer’s disease when compared to people without the disease and those with mild cognitive impairment, often the precursor to the disease.

Using noninvasive optical coherence tomography angiography (OCTA) scanning technology, which utilizes light waves to show blood flow in all layers of the retina, researchers discovered that loss of blood vessels in the eyes could signal Alzheimer’s disease.

In the eyes of the 133 healthy control group participants, there was a dense web of microscopic blood vessels inside the retina of the back of the eye. But in the 39 participants with Alzheimer’s disease, the density of that web was less and sometimes sparse in certain areas.

According to Dr. Dilraj S. Grewal, a lead author on the study, “The concept itself, that there are changes in the eye in Alzheimer’s is not new, we’ve known that for several years; there’s a lot of work that’s been done on that. But being able to look at the blood vessels at this level of detail, that’s a new finding.”

Before OCTA scanning came along, studying the brain involved an invasive procedure involving injecting dye into the body. Besides being noninvasive and taking only a few minutes to complete, an OCTA scan can highlight changes in small capillaries before they can be seen on brain scans like an MRI or cerebral angiogram, which only show bigger blood vessels.

For the almost 6 million Americans living with Alzheimer’s disease, which is currently untreatable, this scan is not only less invasive and less costly, but also holds promise for finding a possible cure.

“If this technology is developed to a level where we can diagnose Alzheimer’s before you start to have cognitive symptoms – before we start to see brain volume loss and a lot of amyloid build up in the brain – then that may open up other targets for intervention where we may be able to intervene earlier in the disease process and prevent worsening,” said Grewal.

“And secondly, this technology may also be useful to monitor change over time, to monitor progression, or lack of, in order to access the effectiveness of therapy.”

Other study others include Sharon Fekrat, Stephen P. Yoon, Atalie C. Thompson, Bryce W. Polascik, Cynthia Dunn and James R. Burke.

The research was made possible with support by National Institutes of Health, the 2018 Unrestricted Grant from Research to Prevent Blindness, and the Karen L. Wrenn Alzheimer’s Disease Award.