Metformin Doesn’t Protect Against AMD, New Study Finds

A study on multiethnic populations from Singapore and a primarily European cohort in the UK found no association between metformin use and AMD risk in patients with diabetes. Photo: Ascend Laboratories. Click image to enlarge. In 2025, a meta-analysis suggested that metformin, a widely used diabetes drug, may be protective against age-related macular degeneration (AMD), but a new cohort study found no convincing evidence that it lowers disease risk. Its authors compared patients with diabetes in Singapore and the UK, finding that metformin use was not associated with reduced AMD prevalence or incidence after adjustment for demographic, clinical and genetic factors. The study, published recently in JAMA Ophthalmology, pooled evidence from two cohorts: the Singapore Epidemiology of Eye Diseases (SEED) study and the UK Biobank. In SEED, 2,869 participants were analyzed; their mean age was 61.1 years, 54.5% were women and all had diabetes. In that cohort, AMD was graded from fundus photographs. The researchers also conducted a sensitivity analysis among participants who were free of AMD at baseline and had medication data at both baseline and follow-up. In the UK Biobank, the team analyzed incident AMD over a median follow-up of 13 years among participants of European ancestry.In SEED, there were no significant differences in AMD prevalence or six-year incidence across antidiabetic medication groups after multivariable adjustment. The adjusted odds ratio for prevalent AMD in metformin users vs. patients taking other non-metformin diabetes drugs was 0.99. For incident AMD, the adjusted odds ratio was 1.07.Notably, the sensitivity analysis of SEED data revealed that the six-year AMD incidence was slightly lower among consistent metformin users than among consistent nonusers (5.4% vs. 8.7%). In the UK Biobank cohort, metformin users initially showed a higher crude incidence of AMD than people taking no antidiabetic medication (3.6% vs. 2.7%). However, after adjustment, the association lost its statistical significance (hazard ratio: 1.13). “We found no association between metformin use and AMD in patients with diabetes when triangulating findings from a multiethnic Asian population cohort and the UK Biobank with comprehensive covariate adjustment,” the researchers concluded in their paper. They cautioned, “Given the observational nature of this evidence, causal approaches would be needed to clarify whether a causal effect exists.”Click here for the journal source. Xue CC, Chee ML, Li H, Tham Y-C, Cheng C-Y. Reported metformin use and age-related macular degeneration in patients with diabetes. JAMA Ophthalmol. June 4, 2026. [Epub ahead of print] This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.