Eye Test May Help Diagnose Alzheimer's

BOSTON--A test that blows puffs of oxygen at the eye identified Alzheimer's patients in a group of elderly people, suggesting it may help in diagnosing the mind-robbing disease, a researcher says.

The test, which employs a form of learning made famous by Russian scientist Ivan Pavlov, identified 19 of 20 people who had been diagnosed with probable Alzheimer's, said Diana Woodruff-Pak. But it also put seven of 20 healthy subjects in the same category, an error rate that must be reduced, she said.

After more research, the procedure may become a useful addition to the battery of tests used to diagnose Alzheimer's, she said.

Woodruff-Pak is a psychology professor at Temple University in Philadelphia and director of the Philadelphia Geriatric Center's Cognitive Neuroscience Laboratory. She spoke at a weekend session of the American Psychological Association's annual meeting, and in a later interview.

Her study is "intriguing, it's tantalizing," said Deborah Claman, program director for neuropsychology at the National Institute on Aging in Bethesda, Md. More research must be done before the test's usefulness can be assessed, she said.

Alzheimer's disease is a progressive neurological disorder. It causes gradual memory loss, impairment of judgment, disorientation, personality changes, difficulty learning and loss of language skills.

Woodruff-Pak's test checks for a form of learning called classical conditioning. Essentially, that is learning to associate one stimulus with another. Pavlov showed dogs can learn that a particular sound meant a meal was coming.

In the new experiment, participants wore an apparatus that placed the mouth of a tube close to one eye. They heard a beep lasting for a half-second, during which the tube blew a puff of oxygen into the eye, making them blink.