Metformin and incidence of age-related macular degeneration in people with diabetes: a population-based 5-year case-control study

Romdhoniyyah, Dewi Fathin, Alshukri, Ayesh, Parry, David G, Harding, Simon ORCID: 0000-0003-4676-1158 and Beare, Nicholas AV ORCID: 0000-0001-8086-990X (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-. ISSN 2397-3269, 2397-3269

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Abstract

Objective Metformin has been identified as a potential treatment for age-related macular degeneration (AMD). Photographic screening for diabetic retinopathy provides an opportunity to conduct a case-control study with systematic AMD grading. We aimed to investigate associations between metformin use and incidence and progression of AMD at different grades. Methods and analysis We randomly sampled 2600 participants from 10336 people aged ≥50 years with diabetes who attended retinopathy screening in 2011 (baseline) and were enrolled to the Individualised Screening for Diabetic Retinopathy study. 2545 of these participants had type 2 diabetes and gradable fundus photographs at baseline, which were graded using modified age related eye disease study grading. We used data including those on metformin prescription from general practitioner records. We used multivariate logistic regression to investigate associations between metformin and incidence or progression of early, intermediate and late AMD. Results Of 2545 participants, 2089 attended and had gradable fundus images on year 5. Metformin was associated with reduced incidence of intermediate AMD by 5 years after adjusting for confounders (complete record OR 0.63, 95%CI 0.43 to 0.92, p=0.02). In univariate analysis, metformin was associated with reduced incidence of late AMD (OR 0.43, 95% CI 0.21 to 0.88, p=0.02) but this did not remain significant after adjusting for age and sex. The numbers progressing to late AMD were small. There was no association between metformin and the incidence of early AMD. Conclusion We have found a significant association between metformin use and reduction in incidence of intermediate AMD by 37% in people with diabetes over 5 years. Previous epidemiological studies of metformin and AMD have used secondary data on AMD. In this observational study, there were baseline differences between groups, although significant findings remained after adjusting for important confounders. Given metformin’s anti-ageing therapeutic effects, the reduction in risk is plausible and warrants prospective clinical trials.

Item Type:	Article
Uncontrolled Keywords:	Macular Degeneration, Drugs, Treatment Medical, Retina
Divisions:	Faculty of Health & Life Sciences Faculty of Health & Life Sciences > Inst. Life Courses & Medical Sciences Faculty of Health & Life Sciences > Inst. Life Courses & Medical Sciences > Inst. Life Courses & Medical Sciences (T&R staff) Faculty of Health & Life Sciences > Inst. Life Courses & Medical Sciences > Eye & Vision Sciences
Depositing User:	Symplectic Admin
Date Deposited:	10 Feb 2026 10:58
Last Modified:	16 Jun 2026 20:07
DOI:	10.1136/bmjophth-2025-002339
Open Access URL:	https://bmjophth.bmj.com/content/11/1/e002339
Related Websites:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3196951
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