We don’t think of the eyes as being an extension of the brain, but they are! In fact, eye health can mirror brain health. New research shows certain eye exams can determine the likelihood of developing Alzheimer’s.
According to the American Academy of Ophthalmology, two recent studies show there is a way of detecting signs of Alzheimer’s in a patient’s eyes in a matter of seconds. A new imaging device called optical coherence tomography angiography was used in the research studies. It enables physicians to see the smallest veins in the back of the eye. Since the optic nerve connects the eyes to the brain, researchers believe the eyes mirror the changes going on in the brain.
The results show people with Alzheimer’s have altered, small blood vessels in their retina at the back of the eye. Even people who simply have a family history of Alzheimer’s but no signs of the illness showed altered red blood vessels.
Diagnosing Alzheimer’s is challenging. Current techniques can detect signs of the disease but aren’t practical for screening large amounts of people. This means people are often only diagnosed once their behavior changes, meaning the disease is progressing. There is currently no cure for Alzheimer’s, but early detection is critical to future care.
“This project meets a huge unmet need,” Sharon Fekrat, M.D., professor of Ophthalmology at Duke University, said. “It’s not possible for current techniques like a brain scan or lumbar puncture (spinal tap) to screen the number of patients with this disease. Almost everyone has a family member or extended family affected by Alzheimer’s. We need to detect the disease earlier and introduce treatments earlier.”
Genes obviously play a huge role in how Alzheimer’s progresses, so a team of researchers from Sheba Medical Center in Israel conducted a study around it. They examined 400 people who had a family history of this illness but showed no signs or symptoms themselves. The researchers compared their retina and brain scans with those who have no family history of Alzheimer’s. They found that the inner layer of the retina is thinner in people with a family history. The brain scan showed the hippocampus (the area of the brain first affected by the disease) had already begun to shrink. The study also showed a thinner inner retina layer and smaller hippocampus were associated with scoring worse on a cognitive function test.
Ygal Rotenstreich M.D., an ophthalmologist at the Goldschleger Eye Institute at Sheba Medical Center, said he is worried for these people with a family history of Alzheimer’s.
“A brain scan can detect Alzheimer’s when the disease is well beyond a treatable phase,” said Rotenstreich. “We need treatment intervention sooner. These patients are at such high-risk.”