A new study has found that people taking the weight-loss drug semaglutide, sold under brand names Ozempic and Wegovy, may be at increased risk of developing a rare eye condition that can cause blindness. The research, published in JAMA Ophthalmology and conducted by Harvard University, analysed data from over 16,800 patients at a Harvard teaching hospital over six years.
The condition, non-arteritic anterior ischemic optic neuropathy (NAION), occurs when blood supply to the optic nerve is blocked, leading to oxygen deprivation and potential vision loss. There is currently no known treatment for NAION, which affects about 10 in 100,000 people in the general population.
Among patients with type 2 diabetes, those prescribed semaglutide were more than four times as likely to develop NAION compared to those on other diabetes medications. Over three years, 8.9% of diabetes patients on semaglutide experienced NAION, versus 1.8% on other drugs. For overweight or obese patients, the risk was even higher: 6.7% of those on semaglutide developed NAION, compared to 0.8% on other weight-loss drugs, a more than sevenfold increase.
Professor Joseph Rizzo of Harvard Medical School called the findings “significant but tentative,” stressing the need for larger studies. He advised that patients, particularly those with existing optic nerve issues, should discuss this risk with their doctors. Novo Nordisk, the manufacturer of Ozempic and Wegovy, stated that NAION is not listed as a known side effect in their product labels and emphasised patient safety as a top priority.
