AJMC links semaglutide to severe eye injury

AJMC reported that semaglutide has been linked to a higher risk of nonarteritic anterior ischemic optic neuropathy, or NAION, a rare optic nerve injury that can cause sudden vision loss. The December 17, 2024 article cited two studies from the University of Southern Denmark that found the risk more than doubled in patients with type 2 diabetes using the drug. The condition remains uncommon, and the researchers and outside specialists did not present the findings as proof that semaglutide directly causes the injury. The reporting adds to a growing body of evidence that has pushed regulators, ophthalmologists and diabetes specialists to scrutinize the drug’s eye-safety profile more closely. ### What eye injury is at the center of this story? NAION is a loss-of-blood-flow injury to the optic nerve that typically presents as sudden, painless vision loss in one eye. The American Academy of Ophthalmology said the condition is rare, with estimated annual incidence ranging from 2.3 to 10.2 per 100,000 people older than 50. Diabetes, obstructive sleep apnea and vascular risk factors are already known to be associated with NAION, which makes this population difficult to study. (ajmc.com) ### What did the studies actually find? The Danish-Norwegian cohort study found semaglutide use was associated with a pooled hazard ratio of 2.81 for NAION compared with sodium-glucose cotransporter-2 inhibitors. The same study estimated an absolute risk increase of 1.41 NAION events per 10,000 person-years, and the authors said the excess absolute risk was low. The paper included 44,517 semaglutide users in Denmark and 16,860 in Norway, with 32 NAION events observed. (ajmc.com) A March 27, 2025 JAMA Ophthalmology study using TriNetX data from 3,344,205 patients with diabetes also found a higher risk signal at longer follow-up. That study reported no clear increase at one month, three months, six months or one year, but found elevated risk at two, three and four years after the index date, with hazard ratios of 2.39, 2.44 and 2.05, respectively. The authors said the findings suggested a potential risk but required further confirmation. (medrxiv.org) ### Why are doctors treating this as a signal, not a final answer? JAMA Ophthalmology commentary published in July 2024 said the early semaglutide findings should not be extrapolated to prove causality. The studies are observational, which means they can identify associations but cannot fully separate the drug from the underlying risk carried by diabetes, obesity, sleep apnea and related vascular disease. The American Academy of Ophthalmology said later studies produced mixed results, leaving debate over how large the risk is, or whether it reflects drug exposure alone. (jamanetwork.com) ### What are regulators and clinicians doing with that signal? The European Medicines Agency said its safety committee concluded NAION should be listed as a “very rare” side effect of semaglutide medicines including Ozempic, Rybelsus and Wegovy. EMA said trial data also pointed to a slightly higher risk in people taking semaglutide than placebo and advised patients with sudden vision loss or rapidly worsening eyesight to seek medical care without delay. (jamanetwork.com) The World Health Organization later summarized the same European action in a June 27, 2025 notice. ### What does this change in practice right now? AJMC’s report said the immediate clinical response is not to stop using semaglutide across the board, but to weigh risks and benefits carefully and take a more specific medication history in patients with unexplained severe vision loss. For ophthalmologists and emergency clinicians, that means asking about semaglutide and other GLP-1 drugs, documenting why the drug was prescribed and how long the patient has been taking it. (ema.europa.eu) For prescribers, the evidence so far supports counseling patients about rare visual symptoms while keeping the small absolute risk in view. October 2025 guidance from the American Academy of Ophthalmology said the research remained unsettled and described semaglutide as widely used for type 2 diabetes and obesity. EMA has already moved to update European product information, and additional observational studies and label changes are the next concrete milestones for clinicians tracking the issue. (aao.org) (ajmc.com)