The FINANCIAL -- Study, by University of Washington (UW) researchers, involved 3,877 adults age 65 and older, who were part of an ongoing, prospective cohort study initiated in 1994 ("Adult Changes in Thought"). From the outset, dementia-free, study participants were assessed for poor vision and cognition, researchers say, but they were followed over time until they developed dementia, dropped out or died. Alzheimer's, a chronic, progressive neurodegenerative disease, is a leading cause of dementia.
In the study, published Aug. 8 in Alzheimer's & Dementia, the journal of the Alzheimer's Association, researchers looked at Alzheimer's risk for glaucoma, age-related macular degeneration (AMD), diabetic retinopathy and cataracts.
They found that glaucoma, AMD and diabetic retinopathy were associated with increased risk for Alzheimer's, controlling for several factors including age, sex, education and smoking. Not so for cataracts.
"There was no association between cataract and Alzheimer's disease," the researchers say. "Without a temporal window, 20 percent higher Alzheimer's disease risk was found in participants with AMD and 44 percent higher Alzheimer's disease risk in those with diabetic retinopathy compared with those without.
According to AOA, "when separated recent versus established ophthalmic conditions, we found a 46 percent higher Alzheimer's disease risk in participants with recent glaucoma compared with those without, but no increased risk for those with established glaucoma," they say. "In comparison with those without AMD, Alzheimer's disease risk in participants with recent and established AMD were 20 percent and 50 percent higher; only the latter was statistically different from the null. Participants with recent and established diabetic retinopathy were at a higher Alzheimer's disease risk by 67 percent and 50 percent compared with those without."
It would be tempting to dismiss the findings as "age-related phenomena," they add. Researchers conjectured in the study that the findings were due to more than that, the potential impact of their neurodegenerative pathways.