Can Alzheimer’s Be Diagnosed by an Eye Test?
By Eric Wicklund
Could healthcare providers soon be able to diagnose Alzheimer’s disease through an eye test?
Researchers at Cedars-Sinai Medical Center are touting the results of three recent studies that indicate an eye test could be used to assess the eye-brain connection, which would allow clinicians to diagnose Alzheimer’s earlier and begin treatment.
“The retina, a layer of tissue at the back of the eye, is part of the central nervous system and is directly connected with the brain,” Maya Koronyo-Hamaoui, PhD, a professor of neurosurgery, neurology and biomedical sciences at Cedars-Sinai and senior author of all three studies, said in a press release. “It has similar cell types and vascular structures to the brain, but is not shielded by bone, so it is more accessible to noninvasive imaging. Our latest research unearths new details about the eye-brain connection.”
Healthcare leaders are looking for innovative and less-invasive strategies to diagnose Alzheimer’s disease, which affects some 5.8 million Americans; that number is expected to jump by 14 million by 2060. Alzheimer’s accounts for some 60% to 80% of dementia diagnoses, and leads to roughly $413,000 in lifetime healthcare costs per patient. Nationally, the price tag for Alzheimer’s care was estimated in 2020 to be $385 billion.
At Cedars-Sinai, researchers launched a study to analyze tau, a protein that helps stabilize the structure of nerve cells in the brain and retina and a critical marker for Alzheimer’s. They found that higher levels of abnormal tau in the retina corresponded to brain changes related to Alzheimer’s, as well as cognitive decline.
A second study, focusing on clumps of protein called amyloid plaques, found two to three times as many plaques clustered near blood vessels in the retinas of patients diagnosed with Alzheimer’s or mild cognitive impairment. A third study focused on other Alzheimer’s biomarkers in the retina, including reduced blood flow, inflammation, nerve cell damage, damage to the barrier that prevents harmful substances from entering retinal tissue, and deposits of amyloid-beta proteins inside blood vessel walls.
“Imaging technology now being developed will allow us to see these changes in patients in clinical settings,” Keith L. Black, MD, chair of the Department of Neurosurgery and the Ruth and Lawrence Harvey Chair in Neuroscience at Cedars-Sinai and co-author of the studies, said in the press release. “This technology, which is noninvasive and affordable, allows us to see changes in the cells and blood vessels in tremendous detail.”