Metformin associated with reduced risk of glaucoma and macular degeneration: Study

Recent studies suggest that the diabetes drug metformin has a protective effect on open-angle glaucoma (OAG) and age-related macular degeneration (AMD). However, studies have not addressed the critical issue of confounding by indication, and associations have not been evaluated in a large prospective cohort.

A study was conducted to determine the association between diabetes medication and the common eye diseases OAG, AMD, and cataracts and to evaluate their cumulative lifetime risks in a large cohort study.

This cohort study included participants from 3 independent cohorts from the prospective, population-based Rotterdam Study between April 23, 1990, and June 25, 2014. Participants were monitored for incident eye diseases (OAG, AMD, cataract) and had baseline measurements of serum glucose. Data on diabetes medication use and data from ophthalmologic examinations were gathered.

Results:

• This study included 11 260 participants
• T2D was diagnosed in 2406 participants (28.4%), open-angle glaucoma (OAG) was diagnosed in 324 of 7394 participants (4.4%), and age-related macular degeneration (AMD) was diagnosed in 1935 of 10 993 participants (17.6%), and cataract was diagnosed in 4203 of 11 260 participants (37.3%).
• Untreated T2D was associated with a higher risk of open-angle glaucoma (OAG), and cataract.
• T2D treated with metformin was associated with a lower risk of open-angle glaucoma (OAG).
• Other diabetes medication (ie, insulin, sulfonylurea derivates) was associated with a lower risk of age-related macular degeneration (AMD)
• The cumulative lifetime risk of open-angle glaucoma (OAG) was lower for individuals taking metformin than for individuals without T2D the lifetime risk of age-related macular degeneration (AMD) was lower for individuals taking other diabetes medication

Thus, results of this cohort study suggest that, although diabetes was clearly associated with cataract, diabetes medication was not. Treatment with metformin was associated with a lower risk of OAG, and another diabetes medication was associated with a lower risk of AMD. Proof of benefit would require interventional clinical trials.

Reference:

Association of Diabetes Medication with Open-Angle Glaucoma, Age-Related Macular Degeneration, and Cataract in the Rotterdam Study, "by Joëlle E. Vergroesen et al. published in JAMA Ophthalmology

doi:10.1001/jamaophthalmol.2022.1435

Keywords:

Metformin, associated, lower, risk, OAG, treatment, diabetes, medication, lower risk, AMD, JAMA Ophthalmology, Cataract, Lens Disorders, Open-Angle Glaucoma, Age-Related Macular Degeneration, and Cataract, Joëlle E. Vergroesen, Eric F. Thee, Fariba Ahmadizar, Cornelia M. van Duijn, Bruno H. Stricker, Maryam Kavousi, Caroline C. W. Klaver, MD, Wishal D. Ramdas, Metformin