Study: Alzheimer’s found in eye exam

Using an easy eye exam, researchers at Washington University of Medicine in St. Louis were able to detect evidence of Alzheimer’s disease in patients before they had symptoms of the disease.

The findings — involving 30 patients — were published Aug. 23 in the journal JAMA Ophthalmology.

Scientists estimate that Alzheimer’s-related plaques begin accumulating in the brain two decades before the onset of symptoms. Physicians can use PET scans and lumbar punctures to detect the plaques, but the tests are expensive and invasive.

Researchers have been looking for ways to detect the disease sooner and test drugs to intervene.

“We know the pathology of Alzheimer’s disease starts to develop years before symptoms appear,” said co-principal investigator Dr. Gregory Van Stavern, “but if we could use this eye test to notice when the pathology is beginning, it may be possible one day to start treatments sooner to delay further damage.”

Longer studies involving more people are needed, but if changes detected with the eye test can be used as markers, people might be in their 40s or 50s, Van Stavern said.

The 30 study participants had an average age in the mid 70s. None was experiencing symptoms. Seventeen had PET scans or lumbar punctures that showed evidence of accumulating plaques. The eye exams of those 17 all detected retinal thinning and large areas without blood vessels in the center of their retinas.

The retinas appeared normal in patients whose PET scans and lumbar punctures were normal.

In previous studies, researchers examining the eyes of people who had died from Alzheimer’s reported their eyes showed signs of thinning in the retina and degradation of the optic nerve.