As prescriptions for semaglutide-containing weight-loss drugs increase around the world, a US study has revealed a higher risk of nonarteritic anterior ischemic optic neuropathy (NAION) when taking this type of medication.

Thought to be a world-first, the observational study published in JAMA Ophthalmology, found that after taking other risk factors into account, semaglutide was associated with a more than four-times greater risk of developing NAION for those taking it for type 2 diabetes and more than seven times for those taking it for obesity.

Popular with Hollywood celebrities and others keen to lose weight quickly, Novo Nordisk’s Ozempic uses semaglutide, a glucagon-like peptide 1 receptor agonist (GLP-1 RA), as its active ingredient.

The researchers, from Massachusetts Eye and Ear, Harvard Medical School, found the association between GLP-1 RA and NAION after looking at data from 16,827 patients from December 2017 to November 2023. Among the cohort, 710 had type 2 diabetes (194 prescribed semaglutide; 516 prescribed non–GLP-1 RA medications) and 979 were overweight or obese (361 prescribed semaglutide; 618 prescribed non–GLP-1 RA weight-loss medications). In the population with type 2 diabetes, 17 NAION events occurred in patients prescribed semaglutide vs six in the non–GLP-1 RA antidiabetes cohort, while for the overweight patient cohort, 20 NAION events occurred in the prescribed semaglutide cohort vs three in the non–GLP-1 RA cohort.