Key Takeaways

• A pharmacovigilance analysis of the FDA Adverse Event Reporting System found a potential association between semaglutide use and reports of ischemic optic neuropathy

• Injectable semaglutide formulations, particularly those used for weight management, showed a stronger safety signal compared with oral formulations

• Researchers emphasize that the findings show an association rather than causation and highlight the need for further studies to better understand potential risk factors and mechanisms

A new global observational study published in the British Journal of Ophthalmology suggests that certain formulations of semaglutide, a widely used medication for type 2 diabetes and obesity, may be associated with an increased risk of ischaemic optic neuropathy, a rare condition that can cause sudden vision loss.¹

Researchers analyzed more than 30 million adverse event reports from the FDA's Adverse Event Reporting System (FAERS) between December 2017 and December 2024. The goal was to evaluate potential links between semaglutide medications and ischaemic optic neuropathy (ION)—a condition resulting from reduced blood flow to the optic nerve.

The analysis compared risk patterns across different semaglutide formulations used for diabetes and weight management, including injectable and oral versions of the drug.

The study found that injectable semaglutide formulations, particularly those used for obesity treatment, showed a stronger association with reports of optic nerve ischemia compared with other formulations. Researchers suggested that higher doses and faster systemic absorption may partly explain the difference in risk among products. In contrast, the oral formulation Rybelsus, which is absorbed more slowly, did not show a similar signal in the data analysis.

Overall, the findings point to a potential dose-dependent safety signal, though the authors emphasized that the condition remains rare and that observational reporting systems cannot prove causation.

Ischaemic optic neuropathy—often called an “eye stroke”—occurs when blood flow to the optic nerve is reduced, leading to sudden and sometimes permanent vision loss. The condition is one of the most common optic nerve disorders in adults after glaucoma and can occur in people with risk factors such as diabetes, hypertension, or vascular disease. Because clinical trials are typically not large enough to detect rare adverse events, post-marketing surveillance systems such as FAERS are often used to identify potential safety signals once medications are widely prescribed.

Semaglutide, a GLP-1 receptor agonist, has become one of the most widely used therapies for metabolic disease and weight management due to its effectiveness in lowering blood sugar and promoting weight loss.

The researchers noted that while the study suggests a possible association between certain semaglutide formulations and optic nerve ischemia, further clinical studies are needed to confirm causality and better understand risk factors, including dose, treatment duration, and patient characteristics.

Regulatory agencies in several countries have already advised clinicians to remain alert to symptoms of sudden vision loss in patients taking semaglutide and to report suspected adverse events as part of ongoing safety monitoring.

Reference

1. Douros A, Renoux C, Suissa S. Semaglutide and risk of ischaemic optic neuropathy: a pharmacovigilance analysis of the FDA adverse event reporting system. Br J Ophthalmol. Published online March 2, 2026. doi:10.1136/bjo-2025-328483.