A new observational study on Wednesday reported for the first time a potential link between Novo Nordisk's GLP-1 drugs Ozempic and Wegovy and an eye condition that can cause vision loss.

After hearing anecdotes of patients on the diabetes and obesity drugs experiencing nonarteritic anterior ischemic optic neuropathy, or NAION, researchers at Massachusetts Eye and Ear analyzed data from a registry of patients at their institution to see if there was a broad trend.

Among 710 patients with type 2 diabetes, there were 17 cases of NAION in patients prescribed semaglutide (the scientific name of both drugs). This translated to a cumulative...