We use our eyes to scan the menu and watch our favorite show, but could they also help doctors determine if we are at risk for developing Alzheimer’s? We may be one step closer to this reality, thanks to researchers at Cedars-Sinai Medical Center. They showed that non-invasive retinal imaging could detect and quantify beta-amyloid deposits in the eyes of patients with Alzheimer’s disease.
Looking at the eyes for Alzheimer biomarkers is somewhat novel, as researchers have largely focused on the role of beta-amyloid deposits in the brain. Beta-amyloid deposits are formed by fragments of the amyloid precursor protein, which is found in the tissue surrounding brain cells. In Alzheimer’s, these fragments will aggregate together, and form plaques that surround healthy brain cells. These plaques can disrupt cell communication and can trigger inflammatory processes. The accumulation of these plaques can occur years before a clinical diagnosis of dementia (often referred to as prodromal Alzheimer’s disease) can be given.
In order to image the retina, subjects were orally administered curcumin, a component of the spice turmeric. Curcumin labels amyloid plaques, and emits a fluorescence signal, which allows researchers to identify and quantify amyloid-beta plaques using their imaging software. After scanning the eyes of 10 Alzheimer’s disease (AD) patients, and 10 healthy controls, they found that those with AD had a 4.7 fold increase in the number of retinal amyloid-plaques. Researchers also found similar results when analyzing the retinas of 23 deceased AD patients and 14 controls, reporting an increase in amyloid-plaques in AD patients.
Importantly, a strong correlation was observed between the number of retinal and brain plaques in patients with AD. Future studies will look to determine when the accumulation of retinal plaques begin, as well as testing the imaging on a larger sample size. Taken together, these findings provide a promising non-invasive, cost-effective, diagnostic for a disease that will cost the nation $259 billion dollars in 2017.
Published August 17, 2017 in JCI Insight