Type 2 diabetes (T2D) is an important risk factor for glaucoma, and sodium-glucose co-transporter 2 (SGLT2) inhibitors have been shown to protect the optic nerves. We therefore aimed to evaluate the association between SGLT2 inhibitors and incident glaucoma.

This retrospective cohort study analyzed the largest multi-institutional electronic medical records database in Taiwan, containing data of over a million individuals. We included T2D patients newly prescribed SGLT2 inhibitors or glucagon-like peptide-1 receptor agonists (GLP-1 RAs) from 2016 to 2018. Our primary outcome was incident glaucoma diagnosis between initiation of SGLT2 inhibitors or GLP-1 RAs, and 31st March 2021. After applying inverse probability of treatment weighting (IPTW) to increase homogeneity between the two treatment groups, we estimated hazard ratios (HR) with 95% confidence intervals (CI) for the risk of glaucoma, based on Cox proportional hazards regression models.

We included 9,927 and 1,065 T2D patients who had been newly prescribed SGLT2 inhibitors or GLP-1 RAs, respectively. Lower risk of incident glaucoma was observed in patients receiving SGLT2 inhibitors (7.9 events per 1,000 person-years), compared to those receiving GLP-1 RAs (10.0 events per 1,000 person-years), with an HR of 0.81 (95% CI: 0.69–0.95). Multiple sensitivity analyses and a negative control outcome analysis confirmed the robustness of our main findings.

This study suggests that T2D patients newly prescribed SGLT2 inhibitors have a reduced risk of incident glaucoma, compared to those prescribed GLP-1 RAs, in clinical practice. Future prospective studies are suggested to confirm this association.