Abstract
Purpose :
Recent studies suggest that the antidiabetic drug metformin has a significant protective effect on age-related macular degeneration (AMD). These studies were based on large registries, were retrospective, mostly case-control designed, and not specific to AMD stage. Here, we evaluated the association between diabetes, metformin, other antidiabetic medications and incident any or late AMD in a large prospective, population-based study.
Methods :
In total, 12,939 individuals aged 45+ years from the population-based Rotterdam Study were available for analyses. Diabetes diagnosis was based on general practitioners’ records, hospital discharge letters and serum glucose measurements. Diabetic medication data were obtained through linkage with the computer network of pharmacies in the study district and were categorized as monotherapy of metformin, monotherapy of insulin, monotherapy of sulfonylurea, any monotherapy and any combination therapy. AMD features and diagnosis of late AMD were assessed by the EyeNED Reading Center on multimodal imaging. Associations between diabetes, the treatment groups, and incident AMD were determined by Cox regression adjusted for age, sex, BMI, use of statins, antihypertensives and fasting serum glucose.
Results :
A total of 1,723 participants were diagnosed with diabetes, of them 688 (40%) used metformin as monotherapy. 1,091 participants were diagnosed with incident any AMD, and 172 with late AMD during a mean follow up time of 6.6 (SD 5.5) years. Diabetes was associated with a lower risk of any AMD (HR 0.74, 95%CI 0.63-0.85), but not significantly associated with late AMD (HR 0.99, 95%CI 0.67 - 1.46). Monotherapy of metformin was borderline associated with any AMD (HR 0.57, 95%CI 0.29 – 1.04), not significant for late AMD (HR 0.51, 95%CI 0.12– 2.27). None of the other medications were significantly associated with any or late AMD, but also had risk estimates which seemed slightly protective (HRs 0.7-0.9).
Conclusions :
Our study shows that it is challenging to dissect the effect of treatment from that of the indication in the study of antidiabetic drugs and AMD. If any, metformin has a greater protective effect on AMD than other medications in diabetic patients, but the clinical significance remains to be elucidated in large prospective studies.
This is a 2021 ARVO Annual Meeting abstract.