Eye test may predict Alzheimer's risk 20 years before symptoms emerge

Good news! Now an eye test can predict Alzheimer's disease two decades prior to symptoms emergence, claims a new study.

Comparing their results to brain scans, the eye test was just as successful at spotting those with twice the amount of plaque build-up in their brains.

According to experts this is the first sign of a cost-effective and non-invasive test.

Study's senior lead author Dr Maya Koronyo-Hamaoui from Cedars-Sinai said that the findings suggested that the retina may serve as a reliable source for Alzheimer's disease diagnosis.

"One of the major advantages of analysing the retina is the repeatability, which allows us to monitor patients and potentially the progression of their disease," Koronyo-Hamaoui added.

The Cedars-Sinai research team collaborated with investigators at NeuroVision Imaging, Commonwealth Scientific and Industrial Research Organisation, University of Southern California, and UCLA to translate their noninvasive eye screening approach to humans.

They conducted a clinical trial on 16 AD patients, who drank a solution that includes curcumin, a natural component of the spice turmeric.

The curcumin causes amyloid plaque in the retina to "light up" and detected by the scan.

The patients were then compared to a group of younger, cognitively healthy individuals.

They found their results were as accurate as those found via standard invasive methods.

Yosef Koronyo, a research associate in the Department of Neurosurgery, said another key finding from the new study was the discovery of amyloid plaques in previously overlooked peripheral regions of the retina.

He said the plaque amount in the retina correlated with plaque amount in specific areas of the brain.

This research only involved a very small number of people and it did not show whether these retinal changes could be detectable before people develop symptoms.

The researchers concluded that it would be too soon to tell whether this test will one day be useful for diagnosis of dementia but this is an active area of research.

The research appears in the journal JCI Insight.