The Association Between Metformin Use and New-Onset ICD Coding of Geographic Atrophy.

Area of Science:

• Ophthalmology
• Gerontology
• Pharmacology

Background:

• Age-related macular degeneration (AMD) is a leading cause of vision loss in older adults.
• Geographic atrophy (GA) is a severe, irreversible subtype of AMD.
• Metformin, a common diabetes drug, has shown potential protective effects against AMD in observational studies.

Purpose of the Study:

• To investigate the association between metformin use and the incidence of geographic atrophy (GA).
• To analyze metformin's effect on GA development in a large patient database.

Main Methods:

• A case-control study was conducted using the Merative MarketScan Commercial and Medicare Databases (2017-2021).
• Patients aged 60+ with new-onset GA (cases) were matched to controls without GA using propensity scores.
• Metformin exposure was assessed in the year prior to the index visit; multivariable logistic regression was used for analysis.

Main Results:

• In the overall cohort (10,505 GA cases), metformin use was associated with a 12% reduction in the odds of new-onset GA.
• In a subgroup of patients without diabetes (7,611 GA cases), metformin use was associated with a 47% reduction in the odds of new-onset GA.
• These findings were adjusted for AMD risk factors and comorbidities.

Conclusions:

• Metformin may serve as a potential noninvasive agent for preventing GA.
• The findings are significant given current therapeutic limitations for GA and metformin's favorable safety profile.
• Further research and clinical trials are warranted to validate these results.