Could the key to detecting Alzheimer’s disease before it savages the brain be in the eyes? A recent study published in in JAMA Ophthalmology says it’s a possibility.

In the study, doctors examined the eyes of older people who had no signs of dementia and found abnormalities in the retinas of those who also had biomarkers for the disease, which can predict whether a person who has normal cognition now will go on to develop Alzheimer’s.

There’s a large body of literature showing structural changes in the retina and the optic nerve in patients with established Alzheimer’s disease so researchers could look for pathologic changes in the brain that parallel the changes in the eye.

The study involved 30 people who showed no signs of dementia, but 14 of them were diagnosed with preclinical Alzheimer’s based on their positive biomarkers, as measured by a PET scan or cerebral spinal fluid testing, or both.

The researchers examined each person’s retina and optic nerve using optical coherence tomographic angiography (OCTA), It turned out an area in the center of the retina without any blood vessels was much larger in the participants who had the biomarkers for Alzheimer’s than those who didn’t. It was also thinner.

Of course, more research is needed but this could be a big step forward in finding and treating Alzheimer’s as early as possible.

Read the study here.