Help pack a million meals for struggling seniors on 9-11. Volunteer today

AARP Bulletin

Health Discovery

An Eye Test Aids Early Diagnosis of Alzheimer's Disease

Noninvasive retinal scan shows signs of early stages

En español | A noninvasive scan that measures the width of blood vessels in the back of the eye shows promise as a way to help diagnose Alzheimer's disease in its early stages, an Australian researcher reports.

Subscribe to the AARP Health Newsletter

Shaun Frost, a scientist at the Australian e-Health Research Center, found that blood vessel changes in the light-sensitive tissue of the retina reflect an accumulation of amyloid plaque in the brain, thought to be an early sign of Alzheimer's.

New study explores retina characteristics as possible biomarkers for Alzheimer’s disease

Noninvasive retinal scan could show early stages of Alzheimer's disease. — Photo by: Jacques M. Chenet/Corbis

"We're seeing signs of the plaque burden increasing in the brain a long time before we see the cognitive deficits of Alzheimer's disease," Frost said during a presentation at the 2011 Alzheimer's Association International Conference in Paris last month.

Frost measured the size of the retinal arteries and veins, then calculated a ratio between the two. He found that in people with Alzheimer's disease, the veins get smaller and the arteries appear to get bigger, proportionately.

"The artery-to-vein ratio in the retina was higher in Alzheimer's disease," Frost told the conference. And, he said, "if we look specifically at just the veins, we see a thinning of those in Alzheimer's disease."

Frost scanned the eyes of 13 older people diagnosed with Alzheimer's and 13 with mild cognitive impairment, comparing them with healthy people. "It's not likely this test would be a stand-alone, definitive test for Alzheimer's disease," he said. But, he added, it could be used in conjunction with other new, very expensive screening tests.

William Klunk, M.D., an Alzheimer's expert at the University of Pittsburgh, agreed, saying in a discussion at the conference that current tests — special scans and spinal taps used to detect Alzheimer's-related changes in the brain — are a bit too invasive and expensive for widespread use as screening tools. He pointed out, however, that Frost's test uses equipment you'd find in any optometrist's office, simply measuring the width of the blood vessels.

Next: How the new test could be used. »

Topic Alerts

You can get weekly email alerts on the topics below. Just click “Follow.”

Manage Alerts


Please wait...

progress bar, please wait

Tell Us WhatYou Think

Please leave your comment below.

AARP Staying Sharp: Keep Your Brain Healthy


Discounts & Benefits

From companies that meet the high standards of service and quality set by AARP.

Walgreens 1 discount membership aarp

Members can earn 50 points per $1 spent on select health & wellness products at Walgreens.

member benefit aarp hear usa

Members save 15% on easy listening devices and more at the HearUSA Hearing Shop.

Eye Med 4 Membership Benefit AARP Discount

Members save up to 60% on eye exams and 30% on glasses at Target Optical.

Membership Benefits Discounts Email Genius

Brain boost? Get AARP email for access to memory exercises & more that help you focus.

Rewards for Good

Your Points Balance:

Learn More

Earn points for completing free online activities designed to enrich your life.

Find more ways to earn points

Redeem your points to save on merchandise, travel, and more.

Find more ways to redeem points