Hundreds of consumers across the United States have filed lawsuits against the manufacturers of GLP‑1 receptor agonists, alleging that the popular weight‑loss and diabetes drugs may raise the risk of a rare eye condition known as nonarteritic anterior ischemic optic neuropathy (NAION). NAION, described by the American Academy of Ophthalmology and the National Eye Institute as an “eye stroke,” results from a sudden reduction in blood flow to the optic nerve and can cause abrupt, painless vision loss in one eye.
Medical perspective on NAION
Dr. Douglas Lazzaro, an ophthalmologist at NYU Langone Health, explained that NAION has no proven treatment and can lead to profound, often permanent vision loss. The condition is most common in adults over age 50, with an estimated incidence of roughly two to ten cases per 100,000 people each year.
Studies and findings
Research published in JAMA Ophthalmology in 2025 examined 37 million adults and found a modest increase in NAION risk among users of semaglutide compared with users of SGLT2 inhibitors, another class of diabetes medication. A 2024 Harvard Medical School study reported that patients with type 2 diabetes prescribed semaglutide faced about a four‑fold higher relative risk of NAION, though the absolute risk remained very low.
Both studies were observational and could not establish a direct causal relationship between the drugs and the eye condition. Researchers noted that many patients taking GLP‑1 drugs also have diabetes, obesity, hypertension, high cholesterol, sleep apnea or smoking habits—known risk factors for NAION—making it difficult to isolate the medication’s effect.
Company responses
Manufacturers Novo Nordisk (producer of Ozempic and Wegovy) and Eli Lilly (producer of Mounjaro and Zepbound) have called the lawsuits meritless. Novo Nordisk cited company‑funded research that found no increased NAION risk with its products. Eli Lilly said it continues to monitor safety data and maintains that current studies do not prove the drugs cause the condition.
The U.S. Food and Drug Administration is reviewing the available evidence but has not issued a safety warning or concluded that semaglutide causes NAION. In Europe, the European Medicines Agency has added NAION as a “very rare” adverse reaction to semaglutide product information.
Expert advice for patients
Doctors stress that patients should not discontinue prescribed GLP‑1 therapy without consulting their healthcare provider. For many individuals with diabetes or obesity, the proven benefits of these medications—improved blood‑sugar control and significant weight loss—may outweigh the potential, albeit low, vision risk.
Dr. Lazzaro advises clinicians to assess each patient’s optic nerve anatomy. He notes that a “disc at risk,” where the optic nerve is unusually compact, may warrant caution when prescribing semaglutide. In patients without such risk factors, he believes the overall health advantages of GLP‑1 drugs are compelling.
What patients should watch for
Symptoms of NAION typically appear upon waking and may include sudden, painless vision loss, blurred or dim vision, loss of peripheral vision, or diminished color perception. Because the condition is often permanent, early detection is crucial.
Anyone experiencing these symptoms should seek immediate ophthalmologic evaluation. While the risk appears low, awareness of the warning signs can help preserve vision.
Bottom line
The lawsuits highlight a growing concern among some patients, but the scientific community emphasizes that current evidence does not definitively link GLP‑1 drugs to NAION. Ongoing monitoring by regulators and further research will be essential to clarify the relationship, if any, between these widely used medications and rare eye‑stroke events.
Original reporting: Fox News (HLL/CB) — read the source article.
