Glaucoma Risk with Metformin and Sulfonylurea Therapies in Type 2 Diabetes: A Retrospective Cohort Study

This observational study found associations between diabetes medications and increased glaucoma diagnosis rates but cannot establish causality. Multiple competing explanations exist: reverse causation (clinicians preferentially prescribing metformin to diabetic patients with emerging glaucoma based on prior protective literature), confounding by indication (sicker patients requiring medication having inherently higher glaucoma risk), and detection bias (differential surveillance patterns). The non-significant metformin monotherapy finding (p=0.067) aligns with recent meta-analyses showing no association. While the statistically significant combination therapy association warrants investigation, it should not be interpreted as definitive causation. Prospective studies controlling for disease severity, surveillance patterns, and treatment indication are needed to disentangle these explanations and inform clinical practice.