ByDaniella Gray
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Popular GLP-1 medications used to treat type 2 diabetes and obesity—semaglutide (Ozempic and Wegovy) and tirzepatide (Mounjaro and Zepbound)—may be linked to a small increase in the risk of a rare eye condition that can cause sudden vision loss, according to new research
The study, published in Annals of Internal Medicine, found that people with type 2 diabetes who started taking GLP-1 receptor agonists were slightly more likely to develop ischemic optic neuropathy (ION) than those prescribed other diabetes drugs
ION occurs when blood flow to the optic nerve is reduced, damaging the nerve that carries visual information from the eye to the brain. The condition can cause sudden, painless vision loss and, in some cases, the damage may be permanent
Newsweek reached out to Novo Nordisk and Eli Lilly, manufacturers of several leading GLP-1 medications, for comment
Dr. Chintan Dave, a core faculty member of the Center for Pharmacoepidemiology and Treatment Science at Rutgers Institute for Health, Health Care Policy and Aging Research, told Newsweekthat patients should not stop or reconsider GLP-1 medications solely because of this potential risk
“The potential increase was small—fewer than one additional case per 2,000 GLP-1RA users, while these medications have very well-established benefits for diabetes, obesity, and heart and kidney health. For most patients, those benefits are likely to outweigh this rare risk,” Dave said
…
Patients taking GLP-1 medications should watch for sudden or unexplained changes in vision, including painless vision loss or blurring in one eye, dimming of vision, changes in color perception, or missing areas in their field of view, according to consultant ophthalmic surgeon Mr. Mfazo Hove
“Any sudden change in vision should be treated as a medical emergency,” he told Newsweek. “These symptoms are not always due to ischemic optic neuropathy and often have other explanations, but they should never be ignored or left in the hope they settle.”
Researchers at Rutgers University analyzed U.S. health insurance data from adults aged 18 to 65 with type 2 diabetes between 2017 and 2022. Using a method known as “target trial emulation,” they compared patients initiating GLP-1 drugs with those initiating sodium-glucose cotransporter-2 (SGLT2) inhibitors or dipeptidyl peptidase-4 (DPP4) inhibitors
Among GLP-1 users, the 18-month risk of ION was about 8.5 cases per 10,000 people, compared with 5.5 cases per 10,000 among patients taking SGLT2 inhibitors. When compared with DPP4 inhibitors, the risk was 7.8 cases per 10,000 among GLP-1 users versus 4.2 cases per 10,000 among those taking DPP4 drugs
This equates to roughly three to four additional cases per 10,000 patients treated over 18 months
The researchers stressed that the study identified an association, not proof that the drugs directly cause the condition
More than three-quarters of ischemic optic neuropathy cases are classified as non-arteritic anterior ischemic optic neuropathy (NAION), a rare condition that typically causes sudden blurring, dimming or loss of part of the visual field in one eye. Total blindness is uncommon, but vision deficits are often permanent
Anyone taking a GLP-1 medication who experiences an abrupt change in vision should seek immediate medical attention
The study adds to the growing body of research examining the safety profile of GLP-1 medications, which have surged in popularity due to their effectiveness in weight loss and blood sugar control
Previous studies have produced mixed results on whether these drugs are associated with eye complications, with some analyses finding a modest increase in NAION risk and others finding no elevated risk
Hove emphasized that any potential risk must be weighed against the well-established benefits of GLP-1 medications, which include improved blood sugar control, significant weight loss and a reduced risk of cardiovascular disease
“The right response to this research is vigilance and monitoring, not alarm,” he said
Contact Newsweek editors on this story: Kara Dolman and Sam Wilson
Reference
Reynolds, K.R., O’Malley, K.M., Roy, J.A. and Dave, C.V. (2026). Glucagon-Like Peptide-1 Receptor Agonists and Risk for Ischemic Optic Neuropathy. Annals of Internal Medicine.doi:10.7326/annals-25-00860
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