Blood vessel defects in the retinas of patients’ eyes may foretell the early stages of Alzheimer’s disease, researchers from Cedars-Sinai announced Wednesday.
“The discovery of abnormalities in retinal blood vessels in patients with mild cognitive impairment holds the potential for diagnosing Alzheimer’s years before people show symptoms,” said Dr. Keith L. Black, professor and chair of the Department of Neurosurgery at Cedars-Sinai. “Such early detection could provide insights into the disease and enable treatments to be created.”
The findings offer significant insights into how Alzheimer’s develops, along with major clinical implications, according to Black.
The study, published in the journal Acta Neuropathologica, examined the post-mortem eye tissues of 29 patients who had Alzheimer’s, 11 patients who had mild cognitive impairment and 22 people with normal cognition, and found three abnormalities within tiny blood vessels of the retinas of the Alzheimer’s patients.
The retinal abnormalities were also discovered in the patients with mild cognitive impairment, according to the researchers.
“We revealed early molecular and cellular loss in blood vessels together with accumulation of amyloid-beta deposits, a buildup of a toxic protein, in retinal blood vessel walls of Alzheimer’s patients,” said the study’s senior author, Maya Koronyo-Hamaoui, an associate professor of Neurosurgery and Biomedical Sciences at Cedars-Sinai.
“The buildup of this protein in the brain is a signature of Alzheimer’s. We were able to map these vascular abnormalities and find that certain regions of the retina were more vulnerable,” she said.
The retina, which is at the back of the eye, is easily accessible for live, non-invasive imaging, according to the researchers.
The next step, they said, is to pursue further development of noninvasive high-resolution retinal imaging, potentially targeting pericytes — a type of cell that lines the vessels — and the molecular changes they discovered in blood vessels as a means to diagnose Alzheimer’s.
Researchers from the USC Keck School of Medicine and the Doheny Eye Institute in Los Angeles also worked on the study.
Alzheimer’s disease is estimated to affect more than 5.5 million people in the United States, including about 10% of adults age 65 or older, and the incidence is rising, according to the Alzheimer’s Association.