Researchers found that while glaucoma, age-related macular degeneration and diabetic retinopathy are associated with an increased risk of Alzheimer’s disease, cataract is not.
Diagnoses of glaucoma, AMD and diabetic retinopathy were based on ICD-9 codes for 3,877 participants from the Adult Changes in Thought (ACT) study.
Using the large cohort, researchers determined associations with risk for Alzheimer’s disease of glaucoma, AMD, diabetic retinopathy and cataract.
ACT participants are a population-based sample, 65 years or older and dementia-free at enrollment and recruited from Kaiser Permanente Washington membership rolls, according to researchers.
Participant screening occurred biennially with the Cognitive Abilities Screening Instrument. Dementia diagnoses were determined at consensus conferences using Diagnostic and Statistical Manual of Mental Disorders, 4th Version criteria, and probable and possible Alzheimer’s diagnoses were determined using National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer’s Disease and Related Disorders Association criteria.
The researchers accumulated 31,142 person-years of follow-up, with a mean of more than 8 years per person. Nearly half of the participants were 70 to 79 years old at enrollment, and 42% were male.
There were 792 incident Alzheimer’s cases: 522 probable and 270 possible Alzheimer’s.
Out of the 3,877 participants, 404 (10%) had a glaucoma diagnosis at ACT enrollment, and 290 (7%) developed glaucoma; 347 (9%) had an AMD diagnosis at enrollment, and 689 (18%) developed AMD; 136 (4%) had a diabetic retinopathy diagnosis at enrollment, and 112 (3%) developed diabetic retinopathy; 1,990 (51%) had a cataract diagnosis at enrollment, and 1,446 (37%) developed cataract.
The researchers found that overall, 24% of participants with glaucoma developed Alzheimer’s vs. 20% of those without.
For those with AMD, there was no significantly increase risk, but they found a 50% increased risk for established AMD.
Participants with both recent and established diabetic retinopathy had an increased risk.
Even after controlling for age, sex, education, APOE genotype and smoking, researchers found that glaucoma, AMD and diabetic retinopathy are associated with an increased risk of Alzheimer’s.
They found no association between cataract and Alzheimer’s.
Those with recent and established diabetic retinopathy were at a higher risk, by 67% and 50%, compared to those without, they wrote.
“Several factors suggest the effects we found are specific to these ophthalmic conditions and not merely age-related phenomena,” researchers wrote. – Abigail Sutton
Disclosures: Please see the full study for all authors’ financial disclosures