A new Eye Stroke study analyzing U.S. safety reports suggests that the weight-loss drug Wegovy may carry nearly five times the risk of a rare blinding eye stroke compared with the diabetes drug Ozempic, with men facing the highest risk.
Researchers Find Stronger Eye Stroke Signal With Wegovy
Researchers analyzing more than 30 million reports in the U.S. Food and Drug Administration’s adverse-event database say the drug formulation used for weight loss shows a significantly higher association with a rare optic nerve stroke.
The Eye Stroke study, published in the British Journal of Ophthalmology, examined safety reports involving semaglutide, the active ingredient in both Wegovy and Ozempic. Researchers found that Wegovy carried a nearly fivefold increased risk of ischemic optic neuropathy compared with Ozempic.
Researchers reviewed 31,774 semaglutide-related reports in the FDA Adverse Event Reporting System between December 2017 and December 2024.
Wegovy was linked to 28 cases of the condition, while Ozempic accounted for 40 cases. Overall, 85 cases were reported across all semaglutide products.
The adjusted odds ratio for the risk was 4.74 for Wegovy compared with Ozempic.
“Semaglutide, in any formulation, was the only agent significantly associated with ION,” said lead researcher Edward Margolin of the University of Toronto.
The findings suggest the risk may be related to drug formulation and dosage. Wegovy’s recommended maximum dose is 2.4 milligrams, slightly higher than Ozempic’s 2.2-milligram limit.
Men Show Significantly Higher Risk Than Women
The analysis also found notable sex differences in reported risk.
Men taking Wegovy had roughly three times the risk of optic nerve stroke compared with women. In reporting signals, the risk indicator reached 116.37 in men taking Wegovy.
By comparison, the strongest signal among women appeared in patients taking Ozempic.
The rare condition, often called an “eye stroke,” occurs when blood flow to the optic nerve is reduced, potentially causing sudden vision loss.
Recovery varies widely, said Rudrani Banik of the Icahn School of Medicine at Mount Sinai, who was not involved in the Eye Stroke study.
“About 40% of patients experience some recovery of central vision, but peripheral vision loss may persist,” Banik said.
Even when improvement occurs, vision rarely returns fully to previous levels, she added.
Earlier reports suggest severe vision loss occurs in up to 15% of cases and complete blindness in about 5%.
Experts Urge Caution While Calling For More Research
Despite the findings, experts caution that the analysis cannot prove the drugs cause the condition.
The Eye Stroke study noted that the FDA safety database relies on voluntary reports and does not include detailed patient information. Researchers explained they could not account for several potential risk factors, including diabetes severity, sleep apnea, or optic nerve anatomy.
“The indications are different for the drugs,” Banik said. “Patients taking Ozempic typically have diabetes, while those on Wegovy are often using it for weight loss or cardiovascular risk reduction.”
Sleep apnea and nighttime drops in blood pressure are known risk factors for optic nerve stroke, and obesity is often associated with sleep apnea.
The Eye Stroke study also analyzed other drugs, including metformin, insulin, and the GLP-1/GIP agonist tirzepatide, and found no clear signal for the condition.
Researchers also found no cases linked to the oral semaglutide product Rybelsus.
Scientists say prospective studies are needed to confirm whether dosage or formulation directly increases risk.
In the meantime, ophthalmologists say patients are already asking questions.
“I actually have patients ask me about this,” Banik said. “The public is aware, and physicians need to be prepared to discuss the potential risk.”
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