Cedars-SinaI Medical Center researchers have developed a noninvasive retinal imaging device that can provide early detection of changes indicating Alzheimer’s disease 15 to 20 years before clinical diagnosis.
“In preliminary results in 40 patients, the test could differentiate between Alzheimer’s disease and non-Alzheimer’s disease with 100 percent sensitivity and 80.6 percent specificity, meaning that all people with the disease tested positive and most of the people without the disease tested negative,” said Shaun Frost, a biomedical scientist and the study manager at the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia’s national science agency.
Keith Black, MD, professor and chair of Cedars-Sinai’s Department of Neurosurgery and director of the Maxine Dunitz Neurosurgical Institute and the Ruth and Lawrence Harvey Chair in Neuroscience, said the accumulation of beta-amyloid plaque in the brain is a hallmark sign of Alzheimer’s, but current tests detect changes only after the disease has advanced to late stages.
Researchers believe that as treatment options improve, early detection will be critical, but existing diagnostic methods are inconvenient, costly and impractical for routine screening.
“PET scans require the use of radioactive tracers, and cerebrospinal fluid analysis requires that patients undergo invasive and often painful lumbar punctures, but neither approach is quite feasible, especially for patients in the earlier stages of disease,” he said. Positron emission tomography, or PET, is the current diagnostic standard.
“The retina, unlike other structures of the eye, is part of the central nervous system, sharing many characteristics of the brain. A few years ago, we discovered at Cedars-Sinai that the plaques associated with Alzheimer’s disease occur not only in the brain but also in the retina.