Eye Scan Could Diagnose Asymptomatic Alzheimer's Disease

Alzheimer’s disease has effects on the retina that are similar to its effects on the brain, according to a new study published by JCI Insight. The authors created a noninvasive eye scan that may be able to diagnose asymptomatic Alzheimer’s disease.

Using the investigational eye scan technique, the authors discovered amyloid-beta clumps, a warning sign of Alzheimer’s disease. These findings suggest that the eye scan could be used to identify patients at high risk of the condition.

Currently, more than 5 million Americans have Alzheimer’s disease, but its prevalence is expected to triple by 2050 due to the aging population, highlighting the need for novel diagnostic tools.

Previously, a post-mortem brain analysis was the only way to diagnose Alzheimer’s disease. More recently, physicians have utilized positron emission tomography brain scans of living patients to track disease progression; however, these scans are expensive and require patients to be injected with radioactive tracers, according to the study.

In an effort to reduce costs and create a less invasive approach, the authors collaborated to create the eye scan approach.

Included in the new study were 16 patients with Alzheimer’s disease who drank a solution that contained curcumin, a component of turmeric, according to the study. The authors reported that curcumin illuminates amyloid plaques in the retina. The scan results from the Alzheimer’s disease patients were then compared with a cohort of younger, cognitively healthy patients.

"The findings suggest that the retina may serve as a reliable source for Alzheimer's disease diagnosis," said the study's senior lead author, Maya Koronyo-Hamaoui, PhD. "One of the major advantages of analyzing the retina is the repeatability, which allows us to monitor patients and potentially the progression of their disease."

The authors believe that discovering amyloid deposits in a previously overlooked place in the retina was significant, as it can be imaged easily, according to the study. The authors also found that the amount of amyloid plaques in the retina paralleled the amount in the brain.

"Now we know exactly where to look to find the signs of Alzheimer's disease as early as possible," said first study author Yosef Koronyo, MSc.

These findings show promise as a method to detect Alzheimer’s disease prior to symptom onset and may help implement interventions that slow or inhibit disease progression, according to the study.

"Our hope is that eventually the investigational eye scan will be used as a screening device to detect the disease early enough to intervene and change the course of the disorder with medications and lifestyle changes," said co-lead investigator Keith L Black, MD.