Vision loss lawsuits against Novo Nordisk and Eli Lilly press FDA on NAION warnings

A federal multi-district lawsuit before a Philadelphia judge that alleges GLP-1 medications cause a rare, permanent form of vision loss now involves more than 130 cases, and plaintiffs who say they lost sight after taking semaglutide are calling for a warning on US labels that several other countries already require ^[1][2].

The suits name Novo Nordisk and Eli Lilly, the makers of Wegovy and Ozempic (semaglutide) and Mounjaro and Zepbound (tirzepatide) ^[1]. They center on non-arteritic anterior ischemic optic neuropathy, or NAION, described in the reports as an irreversible condition often called an eye stroke, caused by restricted blood flow to the optic nerve ^[1][2].

Attorneys and plaintiffs say it arrives without warning. "It comes on suddenly, you don't feel it and then it's permanent," said Jason Goldstein, an attorney serving on the multi-district steering committee ^[1]. Goldstein said one client is 33 years old, and another, a 48-year-old man from New York, lost vision in both eyes ^[1].

Diane Wirth, a former nurse practitioner and a plaintiff, said she was prescribed Wegovy in February 2025 to lose weight and woke up weeks later unable to see out of her right eye ^[1]. She said the loss forced her to quit her job and rely on her husband for driving, and that her depth perception is off ^[1][2]. "Once it happens, it's permanent. There's no going back," she said ^[1][2]. Court documents also describe a 60-year-old Easthampton man identified as John A. Smith who was prescribed Wegovy and lost vision in his left eye to NAION ^[1].

A 2024 study in JAMA Ophthalmology by researchers at Mass Eye and Ear in Boston found that diabetic patients prescribed GLP-1 medications were more than four times more likely to be diagnosed with NAION, while overweight patients taking the drugs were more than seven times more likely to receive the diagnosis ^[1]. The lawsuit relies in part on that study ^[2].

Regulators have split. Goldstein said the European and UK labels for semaglutide have been updated to warn about the rare condition ^[1]; the reports did not give the date of those changes. Canada updated safety information for Ozempic and Mounjaro this summer, and Australia recently updated its warning information to tell patients to seek immediate care for sudden vision loss ^[2]. The FDA has not added a NAION warning to US labels, and told Channel 2 Action News it is continuing to evaluate the potential safety of GLP-1s ^[1][2].

The companies dispute a causal link. Lilly said "the evidence does not establish a causal relationship between GLP-1 RAs and NAION," and that it continues to review data, "including any data regarding ophthalmic issues" ^[1][2]. Novo Nordisk said its own study of 96,000 patients found no increased risk ^[1][2].

Why it matters for patients

NAION causes permanent vision loss, and the accounts in these reports say it can appear suddenly, without a warning sign beforehand ^[1][2]. Whether the drugs cause it is disputed: the 2024 study found an association, while Lilly and Novo Nordisk say their reviews do not show a causal link or an increased risk ^[1][2].

US labels for semaglutide and tirzepatide do not mention NAION, while labels and safety information in Europe, the UK, Canada and Australia do ^[1][2]. That means a patient in the US may not see any mention of the condition in the paperwork that comes with the drug, even though patients elsewhere may. The reports do not say whether the alleged risk differs between semaglutide and tirzepatide.

The CDC sent a statement recommending that patients taking GLP-1 drugs consider visiting an ophthalmologist to establish a baseline vision examination ^[1]; Channel 2 reported the CDC said people taking the drugs may want to see an ophthalmologist before starting ^[2].

What happens next

Legal proceedings before the Philadelphia judge could take years to reach an outcome ^[1]. The FDA has not said when it will finish evaluating the safety question, and no date for a US labeling decision has been reported ^[2].