Metformin Use Linked to Lower Odds of Intermediate Age-Related Macular Degeneration: Study Suggests - Video

A recent study published in BMJ Open Ophthalmology suggests that metformin use may be associated with a reduced incidence of intermediate age-related macular degeneration (AMD). Researchers conducted a retrospective analysis of prospectively collected screening data to explore whether metformin prescription influences AMD development over time.

AMD is a chronic, progressive retinal disease and a leading cause of irreversible vision loss among older adults. Despite its growing public health burden, effective therapies remain largely confined to advanced wet AMD, leaving limited options for early or intermediate disease prevention. This therapeutic gap has prompted interest in repurposing existing medications with potential anti-ageing and anti-inflammatory properties.

Metformin, a first-line treatment for type 2 diabetes (T2D), has been linked in previous studies to reduced inflammation, improved mitochondrial function, and decreased oxidative stress—mechanisms relevant to AMD pathophysiology. However, much of the earlier evidence relied on administrative data rather than direct retinal imaging.

The current study analysed retinal fundus photographs from the Individualised Screening for Diabetic Retinopathy (ISDR) study in Liverpool, UK. The final cohort included 2,089 participants aged 50 years or older with clinically confirmed T2D. Retinal images obtained at baseline (2011) and five-year follow-up (2016) were graded using a modified Age-Related Eye Disease Study (AREDS) classification system.

Using multivariable logistic regression, the researchers assessed the association between metformin prescription and incident AMD while adjusting for age, sex, diabetes duration, HbA1c levels, and diabetic retinopathy status. Metformin use was associated with approximately 37% lower odds of developing intermediate AMD, with adjusted odds ratios ranging from 0.63 to 0.66 (p = 0.01–0.02).

No significant associations were observed for early AMD, and although unadjusted analyses suggested a reduced risk of late AMD, this finding did not persist after adjustment. The authors caution that the observational design precludes causal inference and that residual confounding cannot be excluded.

Overall, the findings are considered hypothesis-generating and support further prospective trials to evaluate whether metformin could delay AMD progression. If confirmed, metformin may represent a low-cost preventive strategy for individuals at risk, particularly those with diabetes.

REFERENCE: Romdhoniyyah, D. F., Alshukri, A., Parry, D. G., Harding, S., & Beare, N. A. V. (2026). Metformin and incidence of age-related macular degeneration in people with diabetes: a population-based 5-year case-control study. BMJ Open Ophthalmology, 11(1), e002339. DOI – 10.1136/bmjophth-2025-002339, https://bmjophth.bmj.com/content/11/1/e002339