In recent years, Koronyo-Hamaoui, Ph.D., M.S. (a professor in the Cedars-Sinai Department of Neurosurgery) and her colleagues have discovered the first evidence of the specific diagnostic signs of Alzheimer’s disease-related amyloid beta protein plaques in retinas from Alzheimer’s and mild cognitive impairment patients. In a series of several NIA-funded innovative studies, her team found increased retinal amyloid plaques and associated retina blood vessel and nerve cell degeneration in patients compared to age and sex-matched cognitively healthy individuals.
Her team also created a low-cost, noninvasive technique to detect Alzheimer’s protein plaques at a very high resolution in the retinas of living patients. Additionally, they developed a modified version of a powerful eye imaging tool — the scanning laser ophthalmoscope — that includes a wider look at previously overlooked peripheral regions in the retina. They combine this scan with giving research participants an oral dose of curcumin, a natural compound that lends zest and orange color to Indian spices such as curry and turmeric. Curcumin is naturally drawn to amyloid beta, the protein that comprises Alzheimer’s disease plaques in the brain, making it easier for the researchers to spot.
“You can look at the retina and see things at the molecular, cellular, and vascular levels, like protein aggregates and vascular abnormalities,” said Koronyo-Hamaoui. Her team is exploring if optical retinal imaging with curcumin could be a cost-effective test to identify Alzheimer’s pathology, including in people with mild cognitive impairment. “We uncovered parallels between the effects of Alzheimer’s disease in the retina and brain, and that specific changes in the retinal regions mimic changes in the brain and cognitive status,” she added.
Koronyo-Hamaoui’s team is collaborating with neuropathology experts across the United States, Europe, and Australia to expand their studies into Alzheimer’s retinopathy and visual deficits to see if a similar test can detect buildup of the protein tau, another hallmark of the disease, in the retina. Their hope is to develop affordable, accessible retina-based scanning technology that might someday be used in combination with routine cognitive and brain imaging for the earlier detection of Alzheimer’s and related dementias, Parkinson’s disease, and stroke.
Untreated vision loss can be especially devastating. Using data from the Health and Retirement Study, NIA-funded scientists recently made the case for including vision impairment as a risk factor for dementia, estimating that nearly 100,000 dementia cases in the U.S. could possibly have been prevented with existing vision treatments.
Older adults stop driving, they stop going out, they have difficulty reading, and they don’t exercise as much because they’re afraid of falling. Untreated vision problems really reduce social interaction, emotional well-being, and physical activity, which are all risk factors for cognitive decline.
