Abstract
Purpose :
We used data from a large, prospective, population-based cohort to study the relationship between cataract surgery and risk of developing Alzheimer’s disease (AD).
Methods :
The Adult Changes in Thought (ACT) study is a 25-year-old ongoing cohort study of participants recruited from Kaiser Permanente Washington (KPW) membership rolls, aged ≥ 65 without dementia at enrollment and followed until dementia or death. We used data from a 2018 data freeze. AD and related dementias were diagnosed using established research criteria with near 100% capture rate. Extensive clinical data were obtained during study visits and via KPW electronic medical records. Diagnoses of cataract and cataract surgery procedures were based on ICD-9/10 and CPT codes. We used Cox proportional hazard regression modeling for probable or possible AD, with age as the time axis, controlling for sex, education, presence of one or more APOE ε4 alleles, race (white vs. other) and smoking status (current vs. past or never). Because healthier participants might have been more likely to receive surgery, we built marginal structural models accounting for several health and cognitive factors in secondary analyses.
Results :
A total of 3,719 participants were included (total person-years = 31,152, average= 8.4 years/ person) and there were 840 incident probable or possible AD cases. 1,815 (49%) underwent cataract surgery (mean baseline age 75.5, SD 6.3, 62% female) and 1,914 did not (75.9, 6.7, 56%). The adjusted hazard ratio of developing AD in people who underwent cataract surgery was 22% lower than those who did not undergo cataract surgery (HR=0.78, 95%CI 0.68, 0.91, p=0.001). The protective effect appeared to be stronger within the first 5 years following cataract surgery (HR=0.68, 95%CI 0.56, 0.83, p<0.001) compared to 5-10 years after surgery (HR=0.88, 95%CI 0.74, 1.03, p=0.113). Secondary analyses yielded similar results.
Conclusions :
This is the first prospective, population-based cohort study that used AD research criteria to show that cataract surgery is associated with lower risk of Alzheimer’s disease. This finding does not appear to be due to healthier participants receiving surgery. Further research on the implications of eye conditions and treatments on brain health is warranted.
This is a 2020 ARVO Annual Meeting abstract.