A federally funded study led by Johns Hopkins Medicine announced on July 17 found that popular diabetes medications known as glucagon-like peptide-1 receptor agonists, or GLP-1 RAs, do not statistically alter the risk of developing neovascular age-related macular degeneration in adults with type 2 diabetes who had no prior history of using these drugs.
The research team analyzed de-identified patient data collected from December 2017 through December 2024 across 12 databases managed by the Observational Health Data Sciences and Informatics network. The study included first-time users of several medications: semaglutide (227,971 patients), dulaglutide (68,588), exenatide (5,460), empagliflozin (252,356), sitagliptin (100,083), and glipizide (213,515). Patients were considered first-time users if they had not taken GLP-1 RAs for at least a year and only started them as a second-line treatment after metformin.
Cindy Cai, M.D., principal investigator and Jonathan and Marcia Javitt Rising Professor of Ophthalmology at Johns Hopkins Medicine, said the study was designed to address conflicting research about whether GLP-1 RAs are linked to age-related macular degeneration. "We included other GLP-1 receptor agonists in our analysis to show our findings weren't specific to a single drug," Cai said.
Researchers identified cases of neovascular age-related macular degeneration based on medical codes in patient profiles using two definitions: one requiring both diagnosis and treatment codes and another requiring only diagnostic codes. They conducted two types of analyses—a cohort comparison between medication groups and a self-controlled case-series among those who developed the disease. Both analyses showed that the risk for developing neovascular age-related macular degeneration while taking semaglutide or other studied medications did not differ enough from random chance to be considered significant.
Cai cautioned against generalizing these results beyond adults with type 2 diabetes who use GLP-1 drugs for blood sugar control. "Our study only looked at patients with existing type 2 diabetes who were prescribed semaglutide and other GLP-1 RAs," she said. "But you don't need a type 2 diabetes diagnosis to take these medications, so we can't say if our findings hold true beyond this patient group."
