Protein deposits in the retina and brain appear parallel to possible neurodegeneration, a vision that can lead to easier and faster detection.
Amyloid plaques are deposits of proteins that collect between brain cells, hindering function and eventually causing neuronal death. They are considered a hallmark of
“> Alzheimer’s disease (AD), and the focus of multiple researches designed to reduce or prevent their formation, including the A4 study nationwide.
But amyloid deposits can also occur in the retina of the eye, often in clinically diagnosed patients with AD, suggesting similar pathologies in both organs. In a small cross-sectional study, a team of researchers, led by scientists at the University of California San Diego School of Medicine, compared retinal and brain amyloid tests in patients in study A4 and another study (Longitudinal Assessment of Amyloid Risk and Neurodegeneration) assessing the risk of neurodegeneration in people with low amyloid levels.
Like the proverbial “windows to the soul,” the researchers observed that the presence of retinal spots in the eyes correlated with brain scans showing higher levels of cerebral amyloid. The finding suggests that noninvasive retinal imaging may be useful as a biomarker for early-stage AD risk detection.
The findings were published in the August 17, 2021 issue of Alzheimer’s and dementia.
Amyloid deposits labeled for curcumin fluorescence in a retinal scan. Credit: NeuroVision
“This was a small set of initial data from the screening visit. It involved eight patients, “said lead author Robert Rissman, PhD, professor of neuroscience at UC San Diego School of Medicine and director of the Biomarker Core for the Alzheimer’s Disease Cooperative Study and the Shiley-Marcos Alzheimer’s Disease Research Center. UC San Diego. “But these findings are encouraging, as they suggest that it may be possible to determine the onset, spread, and morphology of the disease (a preclinical diagnosis) using retinal imaging, rather than ‘more difficult and expensive brain scans. We look forward to seeing the results of additional point retinal scans and the impact of solanezumab (a monoclonal antibody) on retinal imaging. Unfortunately, we will have to wait to see and analyze this data when the A4 test ends ”.
The next step, Rissman said, will be to conduct a broader study to more fully document and verify the relationship between retinal amyloid and cerebral amyloid, both transversely and over time.
Reference: “Feasibility study for the detection of retinal amyloid in clinical trials: anti-amyloid treatment in asymptomatic trial of Alzheimer’s disease (A4)” by Jennifer Ngolab, Michael Donohue, Alison Belsha, Jennifer Salazar, Paula Cohen, Sandhya Jaiswal, Veasna Tan, Devon Gessert, Shaina Korouri, Neelum T. Aggarwal, Jessica Alber, Ken Johnson, Gregory Jicha, Christopher van Dyck, James Lah, Stephen Salloway, Reisa A. Sperling, Paul S. Aisen, Michael S. Rafii and Robert A. Rissman, August 17, 2021, Alzheimer’s and dementia.
DOI: 10.1002 / dad2.12199
Co-authors include: Jennifer Ngolab and Shaina Korouri, UC San Diego; Michael Donohue, Alison Belsha, Jennifer Salazar, Paula Cohen, Sandhya Jaiswal, Veasna Tan, Devon Gessert, Paul S. Aisen, and Michael S. Rafii, all at the University of Southern California; Neelum T. Aggarwal, Rush University Medical Center; Jessica Alber, University of Rhode Island; Ken Johnson, NeuroVision Imaging Inc .; Gregory Jicha, University of Kentucky; Christopher van Dyck,
“> Yale University; James Lah, Emory University; Stephen Salloway, Butler Hospital, RI; Reisa A. Sperling, Brigham and Women’s Hospital / Massachusetts General Hospital, Boston.
Funding for this research came in part from the National Institutes of Health and the National Institute on Aging (grants AG062429, AG018440, AG010483, AG063689), Alzheimer’s Association, Eli Lilly and Company, NeuroVision Inc., Accelerating Medicines Partnership, GHR Foundation, Morton Plant Mease Foundation, plus an anonymous foundation and additional private donors.