Study Examines Wegovy and Rare Vision Loss Reports
A new study in the British Journal of Ophthalmology has identified a stronger safety signal for ischemic optic neuropathy, or ION, in reports involving Wegovy than in reports for other semaglutide-based GLP-1 medications. ION is a rare condition in which reduced blood flow to the optic nerve can cause sudden partial or complete vision loss.
Researchers reviewed more than 30.6 million reports submitted to the FDA Adverse Event Reporting System from December 2017 through December 2024. Of these, 31,774 involved semaglutide drugs, including Ozempic, Wegovy and Rybelsus. The review also included tirzepatide drugs such as Mounjaro and Zepbound.
The study found 28 ION reports linked to Wegovy and 47 linked to Ozempic. Although Ozempic had more reports overall, Wegovy showed the strongest statistical association, with odds nearly 75 times higher than expected, compared with nearly 19 for Ozempic. No cases were reported for oral semaglutide, Rybelsus. Researchers also found a stronger signal among men using Wegovy.
The authors said Wegovy’s higher dose and injectable formulation may help explain the difference, possibly through effects involving blood pressure, dehydration or autonomic instability. However, they stressed that the findings do not prove Wegovy causes ION. Public attention to Wegovy may also have affected reporting patterns.
The FAERS database has limits: it cannot show how often a condition occurs, and reports may lack detailed medical information. Still, researchers said the results raise questions for prospective studies, especially as GLP-1 drugs are prescribed more widely for obesity, diabetes and possible cardiovascular or neurological benefits.
Ophthalmology commentators said the findings add to emerging research on potential eye complications from anti-obesity medications. They also noted that GLP-1 drugs may have benefits for some eye diseases, underscoring the need to weigh possible benefits against rare but serious risks.