To do so, they examined 3,877adults aged 65 and older, who were a part of the Adult Changes in Thought database. During the five-year trial, which began in 1994, about 800 of the subjects were diagnosed with Alzheimer’s.
When the University of Washington researchers took a closer look, they found patients with macular degeneration, diabetic retinopathy, or glaucoma were 40 to 50 percent more likely to develop Alzheimer’s, compared to those without these eye conditions. There did not find a connection between cataract and Alzheimer’s.
"What we found was not subtle," coauthor Paul Crane said in a statement. "This study solidifies that there are mechanistic things we can learn from the brain by looking at the eye."
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While the analyst do not know why there is a relationship between the three eye illnesses and the memory loss disease, they wrote, “anything happening in the eye may relate to what’s happening in the brain, an extension of the central nervous system.”
A better understanding of neurodegeneration in the eye and the brain could help diagnose Alzheimer’s early, but they said the connections need to be investigated more.
"We don't mean people with these eye conditions will get Alzheimer's disease," lead researcher Cecilia Lee added. "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."
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