GLP-1 drugs mimic hormones involved in blood sugar control, appetite, and digestion, and are widely used for Type 2 diabetes and weight management. Examples include semaglutide (Ozempic, Wegovy), tirzepatide (Mounjaro, Zepbound), liraglutide (Victoza, Saxenda), dulaglutide (Trulicity), and exenatide (Byetta, Bydureon). Credit: Shutterstock
Rutgers researchers say the risk is low, but patients should still be aware of the possible association.
GLP-1 medications have become widely used for Type 2 diabetes and obesity, with drugs such as semaglutide, sold as Ozempic and Wegovy, and tirzepatide, sold as Mounjaro and Zepbound, among the best-known examples. The drugs can also reduce cardiovascular and kidney disease risks, but their growing use has increased interest in identifying uncommon side effects.
In a study published in Annals of Internal Medicine, Rutgers researchers analyzed a large database of U.S. adults ages 18 to 65 with Type 2 diabetes who had started medications for the disease. They found that patients taking GLP-1 drugs had a slightly higher risk of ischemic optic neuropathy, a rare condition caused by reduced blood flow to the optic nerve that can lead to sudden vision loss.
The overall risk remained low
The increase was small, amounting to approximately three to four additional cases per 10,000 patients treated with GLP-1s over 18 months.
“Although ischemic optic neuropathy was rare, it is clinically important because it can involve sudden vision loss,” said 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. “The increase in risk was small – approximately three to four additional cases per 10,000 patients treated with GLP-1s over 18 months, but clinicians and patients should be aware of this potential association.”
Because GLP-1 medications are increasingly used by people both with and without Type 2 diabetes, the researchers said continued attention to their safety is important even when potential risks are uncommon.
Sudden vision changes warrant prompt attention
“Most patients in our study who had ischemic optic neuropathy were either men or men and women aged 50 to 65,” said Dave, an associate professor at the Ernest Mario School of Pharmacy and the lead author of the study. “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 out of five cases of ischemic optic neuropathy are estimated to involve the non-arteritic anterior form. Dave said the resulting vision loss is usually permanent, although about one third of patients may regain some vision, generally during the first six months. Some impairment often remains even after improvement. Rather than causing total blindness or complete darkness, the condition typically produces blurring, dimming, or loss of part of the visual field in one eye.
The researchers cautioned that the association may be influenced by underlying health differences among patients rather than a direct effect of GLP-1 medications. Additional research will be needed to determine whether the drugs actually cause the increased risk.
Reference: “Glucagon-Like Peptide-1 Receptor Agonists and Risk for Ischemic Optic Neuropathy” by Kamika R. Reynolds, Kimberly M. O’Malley, Jason A. Roy and Chintan V. Dave, 13 July 2026, Annals of Internal Medicine.
DOI: 10.7326/ANNALS-25-00860
Funding: National Institutes of Health
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