Lawsuits Filed Over Vision Loss Risk Linked to GLP-1 Drugs
Hundreds of consumers are suing the manufacturers of GLP-1 receptor agonists, claiming the medications increase the risk of a rare type of vision loss. The affected individuals argue that these drugs have caused NAION, or nonarteritic anterior ischemic optic neuropathy, according to a report by The Wall Street Journal.
Understanding NAION
NAION is a rare condition characterized by sudden reduced blood flow to the optic nerve, leading to vision loss. It is the most frequent cause of acute damage to the optic nerve in adults over 50, as described by the American Academy of Ophthalmology and the National Eye Institute, which refer to it as an “eye stroke.”
Dr. Douglas Lazzaro, an ophthalmologist at NYU Langone Health, explained to Fox News Digital that NAION is problematic due to the lack of available treatments, which can result in significant vision impairment.
Companies’ Response
The manufacturers involved, Novo Nordisk, known for Ozempic and Wegovy, and Eli Lilly, responsible for Mounjaro and Zepbound, have disputed these claims. Novo Nordisk has labeled the lawsuits as lacking merit and highlighted their own research, which found no increased risk of NAION linked to their drugs. Eli Lilly stated that they are continuously monitoring safety data and maintained that current studies do not prove a link between GLP-1 medications and NAION.
Research Findings
Research has predominantly focused on semaglutide rather than tirzepatide. An analysis of data involving 37 million adults, published in JAMA Ophthalmology in 2025, revealed a modest increase in NAION risk among semaglutide users compared to those using SGLT2 inhibitors. A 2024 study from Harvard Medical School indicated that patients with type 2 diabetes prescribed semaglutide had a fourfold higher relative risk of developing NAION, although the absolute risk remained low. Both studies stressed that further evidence was necessary to establish a causal relationship.
The FDA is evaluating existing evidence concerning the potential association of semaglutide with NAION but has not issued a safety warning. Meanwhile, the European Medicines Agency recommended labeling NAION as a “very rare” adverse reaction to semaglutide in product information across Europe.
Risk Factors and Expert Opinions
NAION typically causes sudden, painless vision loss in one eye, with symptoms that may include blurred vision, loss of peripheral vision, or decreased color vision. Risk factors encompass age, diabetes, high blood pressure, high cholesterol, sleep apnea, and smoking.
Given many individuals taking GLP-1 medications have diabetes or obesity, these underlying conditions could contribute to vision issues. Observational studies face challenges in segregating medication effects from disease impacts.
Vision loss from NAION is often permanent, with partial vision recovery possible for some patients over time. Experts advise that patients should not cease taking prescribed GLP-1 drugs without consulting their healthcare provider, considering the proven benefits for diabetes or obesity may outweigh potential vision risks.
An important element in NAION is the “disc at risk,” referring to specific optic disc characteristics that increase vulnerability. Dr. Lazzaro recommends patients with such risk factors should avoid semaglutide.
Lazzaro shared that there’s likely a slight increased risk of NAION with semaglutides but believes the health advantages surpass the risks, advising semaglutide use unless “disk at risk” factors are present.