Hundreds of consumers have filed a lawsuit against manufacturers of GLP-1 receptor agonists, alleging the medications may increase the risk of a rare form of vision loss.
The patients behind the lawsuits allege that the medications caused NAION (nonarteritic anterior ischemic optic neuropathy), according to The Wall Street Journal.
NAION is a rare eye condition in which blood flow to the optic nerve is suddenly reduced, leading to sudden vision loss.
It is the most common cause of acute optic nerve injury in adults over age 50, according to the American Academy of Ophthalmology and the National Eye Institute, which describes it as an “eye stroke.”
“The problem with NAION is there’s no treatment,” Dr. Douglas Lazzaro, an ophthalmologist at NYU Langone Health, told Fox News Digital. “So it can cause some very profound vision loss.”
The companies in question, Novo Nordisk (maker of Ozempic and Wegovy), have disputed the allegations, according to the WSJ report.
Novo says its own assessment/data do not support the plaintiffs’ claims.
A 2024 Harvard Medical School study found that patients with type 2 diabetes who were prescribed semaglutide had approximately a fourfold higher relative risk of developing NAION. The absolute risk remained very low.
The author of the Harvard Medical School study noted that the research was observational and could not prove that the medication caused NAION. They emphasized that more evidence is needed.
Lazzaro agreed that “whether or not that’s statistically significant is hard to assess, because there were so many variables in this and it’s hard to match patients exactly.”Lazzaro continued, “But when they removed all of what they felt were variables—how obese…level of obesity—they did find patients male versus female, age, hypertension, there was a higher risk of NAION.”
NAION typically causes sudden, painless vision loss in one eye, according to the AAO. Other symptoms may include blurred or dim vision, loss of peripheral vision, or decreased color vision.
“My overall take on the matter is there’s probably a slightly increased risk of NAION when using the semaglutides, but I think the health benefits outweigh the risks,” Lazzaro went on.
In June 2025, the European Medicines Agency’s safety committee concluded, after reviewing clinical trials, post-marketing data, epidemiological studies, and other evidence, that NAION is a very rare side effect of semaglutide, the active ingredient in Ozempic, Wegovy, and Rybelsus. Several large epidemiological studies revealed that the risk level is low, as 1 in 10,000 people may experience this effect.
