Manufacturers of blockbuster weight-loss medications such as Ozempic and Zepbound will be required to add warnings about a rare eye condition that can cause permanent vision loss, the U.S. Food and Drug Administration (FDA) announced Monday.
The agency said patients taking GLP-1 medications may face an increased risk of developing a rare condition known as non-arteritic anterior ischemic optic neuropathy (NAION).
NAION, sometimes described as an “eye stroke,” occurs when blood flow to part of the optic nerve is reduced. It can cause sudden, painless vision loss or decreased vision in one eye. There is currently no established treatment for the condition.
“NAION cases have been reported for all currently marketed GLP-1 RA products,” the FDA said, adding that its review identified a potential increased risk among patients taking these medications.
The decision follows a comprehensive review of reported cases and studies involving more than 134,000 patients. The FDA analysis found approximately six cases of NAION per 100,000 people taking GLP-1 medications annually, compared with about four cases among people taking a placebo or other diabetes medications.
The agency also warned that patients who have previously experienced NAION face an increased risk of recurrence.
The announcement follows a May review by the American Academy of Ophthalmology, which found that semaglutide-based medications, including Ozempic and Wegovy, may be associated with approximately twice the relative risk of developing NAION.
Novo Nordisk, the manufacturer of Ozempic and Wegovy, disputed the conclusion that the available evidence establishes a direct link.
“Novo continues to believe the data do not establish a cause-and-effect relationship and we remain confident in the benefit-risk profile of our GLP-1 medicines,” a company spokesperson told Reuters.
Eli Lilly, the manufacturer of other popular weight-loss medications, including Zepbound, said patient safety remains its top priority and that it is evaluating the FDA’s updated guidance.
The company added that it would continue working with regulators and reviewing available evidence concerning potential eye-related side effects.
Approximately 28 million Americans were taking GLP-1 medications, according to a July Gallup poll.
The FDA is urging patients taking these medications to watch for warning signs of NAION, including blurred vision, missing portions of their visual field, distorted colors, hazy spots and vision loss in one eye, particularly upon waking.
Other potential risk factors include smoking, diabetes, high blood pressure, sleep apnea, anemia and kidney disease.
The FDA advises patients experiencing any of these symptoms to contact their healthcare professional immediately.
