Potential Efficacy of Metformin for Age-Related Macular Degeneration: A Systematic Review and Meta-Analysis

Matthew D Huh1,2, Simon N Le1, Kieran S O'Brien1,3

  • 1Department of Ophthalmology, University of California, San Francisco, San Francisco, California.

Ophthalmology Science
|April 15, 2025
PubMed
Abstract

Insights

Metformin may reduce the risk of age-related macular degeneration (AMD). This systematic review found a lower odds of AMD in metformin users, but more research is needed.

Area of Science:

  • Ophthalmology
  • Pharmacology
  • Gerontology

Background:

  • Metformin, a common diabetes drug, possesses antioxidant, anti-inflammatory, and antiangiogenic properties.
  • These properties suggest potential therapeutic benefits for age-related macular degeneration (AMD).

Purpose of the Study:

  • To systematically review and analyze the efficacy of metformin in reducing the prevalence of age-related macular degeneration (AMD).

Main Methods:

  • A systematic search of Embase, MEDLINE, Cochrane Library, and Web of Science databases was performed.
  • Included studies involved oral metformin use prior to AMD diagnosis; data were meta-analyzed using a random-effects model.
  • Subgroup analyses considered study design, AMD subtype, sex, and metformin dosage.

Main Results:

  • Eighteen observational studies with over 2.6 million participants were analyzed.
  • Metformin use was associated with a significant reduction in AMD odds (pooled OR = 0.86).
  • Protective effects were observed in both diabetic and non-diabetic individuals, particularly at lower metformin doses.

Conclusions:

  • Current evidence suggests a potential protective role for metformin against AMD.
  • However, all included studies were observational and carried risks of bias, particularly confounding.
  • Randomized clinical trials are essential to confirm metformin's effectiveness in preventing AMD onset.