GLP-1 medications, commonly used to treat Type 2 diabetes and obesity, may be associated with a slightly increased risk of sudden vision loss, according to researchers at Rutgers University. The condition, known as ischemic optic neuropathy, occurs when blood flow to the optic nerve is reduced, potentially leading to vision loss. Researchers emphasized that the risk is small — about three to four additional cases per 10,000 patients treated with GLP-1 medications over an 18-month period — but said the growing popularity of these drugs warrants close attention to medication safety. Popular GLP-1 medications include semaglutide drugs, such as Ozempic and Wegovy, as well as tirzepatide medications, such as Mounjaro and Zepbound. "Most patients in our study who had ischemic optic neuropathy were either men or women aged 50 to 65," said Prasad Dave, an associate professor at Rutgers' Ernest Mario School of Pharmacy and the study's lead author. "Because ischemic optic neuropathy can present with sudden vision loss, which may be permanent, early recognition of symptoms and prompt ophthalmologic evaluation may be especially important for patients at higher baseline risk." More than four in five cases of the condition are estimated to be the non-arteritic anterior form, meaning the vision loss is usually permanent. However, approximately one-third of patients may experience some improvement, typically within the first six months. Even when vision improves, some degree of impairment often remains. The condition typically causes blurring, dimming or partial loss of the visual field in one eye rather than complete blindness. The study, published in the Annals of Internal Medicine, analyzed data from a large U.S. database of adults ages 18 to 65 who began taking the medications to treat Type 2 diabetes. Researchers said the findings may reflect differences in patients' underlying health conditions rather than a direct effect of the medications themselves.