Association Between Long-Term Metformin Use and Risk of Open-Angle Glaucoma in Patients With Diabetes Mellitus.

Abstract

Prcis: Metformin use wasn't dose-dependently linked to open-angle glaucoma. Lower doses showed a protective effect, while higher doses had no significant impact.

Purpose: The present study examined the enigmatic relationship between long-term metformin use and the risk of developing open-angle glaucoma (OAG) in patients with diabetes mellitus (DM). Additionally, we questioned whether metformin use affects the risk of OAG in a dose-dependent manner.

Methods: This research was a retrospective cohort study using a nationally representative database established by the Health and Welfare Data Science Center of the Ministry of Health and Welfare, Taiwan, ROC. Patients diagnosed with new-onset DM between 2002 and 2013 were divided into two groups: a metformin-treated group and a sulfonylureas-treated group. The aim of our investigation is to evaluate the risk of OAG after a 5-year follow-up period. Using the Cox proportional hazard model, researchers estimated the risk of OAG in correlation with metformin treatment by the cumulative defined daily dose (cDDD), after adjusting for several key risk factors such as sex, age, income, urbanization level, diabetes severity, and various comorbidities.

Result: A total of 2,102 patients (0.29%) developed OAG after 5 years of being diagnosed with DM. Among patients treated with metformin, the incidence rates of OAG were 0.27%, 0.27%, 0.29%, and 0.33% with cDDDs of<30, 30-120, 120-240, and >240, respectively. Following adjustments for relevant variables, patients who received metformin treatment at cDDDs of <30, 30-120, 120-240, and >240 exhibited HRs of 0.81 (95% CI=0.71-0.92), 0.83 (95% CI=0.74-0.93), 0.90 (95% CI=0.79-1.03), and 1.03 (95% CI=0.82-1.29), respectively, compared with those treated with sulfonylureas.

Conclusion: Our findings suggest a moderate protective effect on the risk of open-angle glaucoma at lower cumulative metformin dosages. A dose-dependent effect was not observed.