Alzheimer's Disease Could Be Diagnosed With Eye Test, Research Suggests

An eye test could one day be used to diagnose Alzheimer's disease, according to research.

While there is no cure for Alzheimer's, detecting the condition early is important, as some symptoms are reversible and treatable. But there is currently no one reliable biological test for the disease, and diagnostic methods such as a cerebrospinal fluid test are costly and invasive.

Existing research indicates that amyloid, the protein that collects in the brain of those with Alzheimer's disease, could also affect the retina of the eye. Scientists at Washington University in St. Louis hypothesized that a simple eye test could be used to diagnose the neurodegenerative disease, which affects 5.7 million people in America.

The researchers enlisted 30 adults who showed no signs of dementia and tested them for biomarkers of preclinical Alzheimer's disease.

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Each participant had an optical coherence tomographic angiography examination, which provided images of the vasculature of the eye.

Of the total participants, 14 had biomarkers of Alzheimer's disease. Those individuals also were more likely to have abnormalities in their retinas compared to those without the disease biomarkers.

Scientists tested healthy adults for signs of Alzheimer's disease using an eye test. Getty Images

While the results of the study published in JAMA Ophthalmology were promising, the authors acknowledged that more people must be studied to determine whether such tests could be used to diagnose the disease.

Dr. Doug Brown, chief policy and research officer at the Alzheimer's Society charity who was not involved in the study, commented, "Testing whether changes in the eye, such as those in the retina, might be an early sign of dementia is a fascinating area of research. Yet it is simply too soon to hail this as a new way of diagnosing dementia.

"However, although well conducted, this study was very small, including only 30 people who were studied over a very short amount of time. And without confirming that any of the people with preclinical Alzheimer's actually went on to develop the disease, we would need to see this carried out on a much larger group over a longer period of time to draw any firm conclusions."

Dr. Sara Imarisio, head of research at Alzheimer's Research UK, also praised the authors for exploring a "relatively quick, inexpensive and noninvasive" approach to diagnosing the disease, but also said more research was needed.

The study was published the same week as another paper which found that eye scans could detect Parkinson's disease, as a thinning retina could be a sign of the neurodegenerative condition.