Lawsuits Claim Vision Loss Risk from GLP-1 Medications

Hundreds of consumers are taking legal action against manufacturers of GLP-1 receptor agonists. The allegations suggest these medications could lead to a rare type of vision loss. Patients assert that the drugs caused NAION (nonarteritic anterior ischemic optic neuropathy), as reported by The Wall Street Journal.

Understanding NAION

NAION is an unusual eye condition characterized by a sudden reduction in blood flow to the optic nerve. This results in abrupt, profound vision loss. According to the American Academy of Ophthalmology and the National Eye Institute, it is the leading cause of acute optic nerve damage in adults over 50. Dr. Douglas Lazzaro, an ophthalmologist at NYU Langone Health, told Fox News Digital that NAION lacks any available treatment, which can lead to significant vision impairment.

Company Responses

Several companies, including Novo Nordisk and Eli Lilly, are involved in these allegations. Novo Nordisk, the producer of Ozempic and Wegovy, described the lawsuits as without merit, citing company research indicating no increased NAION risk. Eli Lilly, the maker of Mounjaro and Zepbound, continues to analyze safety data and maintains that there is no evidence to confirm GLP-1 drugs cause this condition.

Research Findings

Most research thus far has focused on semaglutide rather than tirzepatide. An analysis involving 37 million adults, published in JAMA Ophthalmology in 2025, identified a modest NAION risk increase in those using semaglutide compared to others who took SGLT2 inhibitors, another diabetes medication class. A separate 2024 Harvard Medical School study confirmed a fourfold higher relative risk of NAION in type 2 diabetes patients taking semaglutide, while emphasizing the absolute risk is low. Both studies were observational and could not conclusively establish causation.

Regulatory and Medical Perspectives

The FDA is examining available evidence on semaglutide’s potential link to NAION, though no safety warnings have been issued for the medication. In contrast, the European Medicines Agency recommended listing NAION as a ‘very rare’ adverse effect for semaglutide in Europe.

Dr. Lazzaro acknowledged the challenge of gauging statistical significance due to the numerous variables involved, such as age, gender, and obesity levels. After adjusting for confounding factors, the risk of NAION appeared elevated.

Recognizing NAION Symptoms

NAION generally causes sudden, painless vision loss in one eye, often noticed in the morning. Other symptoms include blurred vision, loss of peripheral vision, and reduced color vision. Risk factors for NAION include age, diabetes, high blood pressure, high cholesterol, obstructive sleep apnea, and smoking.

Advice for Patients

Vision loss from NAION is typically irreversible, although some patients may partially recover. Healthcare professionals stress that patients should not discontinue GLP-1 medications without consulting their doctors, as the benefits may outweigh the potential vision risks.

For individuals with specific optic disc conditions, such as a ‘disc at risk,’ Dr. Lazzaro suggests avoiding semaglutide. He emphasizes that the slight risk of NAION is outweighed by the overall health benefits for most patients.