METformin for the MINimization of Geographic Atrophy Progression (METforMIN): A Randomized Trial

Area of Science:

• Ophthalmology
• Gerontology
• Pharmacology

Background:

• Observational studies suggest metformin may reduce age-related macular degeneration (AMD) progression.
• Geographic atrophy (GA) is an advanced form of AMD leading to vision loss.

Purpose of the Study:

• To evaluate the efficacy of oral metformin in slowing the progression of geographic atrophy (GA) in patients with atrophic age-related macular degeneration (AMD).

Main Methods:

• A multicenter, randomized phase II clinical trial involving participants aged 55 years or older without diabetes and with GA.
• Participants were randomized to receive oral metformin (2000 mg daily) or observation for 18 months, with fundus autofluorescence imaging used for monitoring.

Main Results:

• The annualized enlargement rate of GA area did not significantly differ between the metformin and observation groups (0.42 vs. 0.35 mm/year, P=0.26).
• No significant differences were observed in best-corrected visual acuity (BCVA) or low luminance visual acuity (LLVA) between groups.
• Gastrointestinal side effects were the most common non-serious adverse events in the metformin group.

Conclusions:

• This trial does not support the use of oral metformin for reducing GA progression in patients with AMD.
• Further placebo-controlled studies are warranted to investigate metformin's potential role in earlier stages of AMD.