Study finds link between eye diseases and Alzheimer's

There is no simple way to detect Alzheimer's. But now, in a new study, researchers have found that eye conditions provide new lens screening for the disease.

A study of 3,877 randomly selected patients found a significant link between three degenerative eye diseases - age-related macular degeneration, diabetic retinopathy and glaucoma - and Alzheimer' disease.

The results offer physicians a new way to detect those at a higher risk of this disorder, which causes memory loss and other symptoms of cognitive decline.

"We don't mean people with these eye conditions will get Alzheimer's disease. The main message from this study is that ophthalmologists should be more aware of the risks of developing dementia for people with these eye conditions and primary care doctors seeing patients with these eye conditions might be more careful on checking on possible dementia or memory loss," said lead researcher Dr. Cecilia Lee at the UW School of Medicine

The participants in the study were aged 65 and older and did not have Alzheimer's disease at the time of enrollment. Over the five-year study, 792 cases of Alzheimer's disease were diagnosed by a committee of dementia experts. Patients with age-related macular degeneration, diabetic retinopathy, or glaucoma were at 40 percent to 50 percent greater risk of developing Alzheimer's disease compared to similar people without these eye conditions. Cataract diagnosis was not an Alzheimer's disease risk factor.

"What we found was not subtle," said Dr. Paul Crane, at the UW School of Medicine. "This study solidifies that there are mechanistic things we can learn from the brain by looking at the eye."

Lee said anything happening in the eye may relate to what's happening in the brain, an extension of the central nervous system. The possible connections need more study. She said a better understanding of neurodegeneration in the eye and the brain could bring more success in diagnosing Alzheimer's early and developing better treatments.

The study has been published in the journal Alzheimer's & Dementia.