Novo Nordisk's stock dropped by 5.4%, the largest decline in the past month.
Occurrence is extremely rare - slightly more cases than other diabetes treatment drugs.
A study supporting the analysis results of the Harvard University affiliated Ophthalmology Institute, published this year, has revealed the association between Novo Nordisk's diabetes treatment drug Ozempic and an increased risk of rare vision loss.
According to a research team that has been investigating patient records in Denmark and Norway for many years, diabetic patients taking Ozempic are over twice as likely to be diagnosed with a rare condition called Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION) compared to patients using a different type of diabetes treatment drug. This study could not determine if people taking the obesity treatment drug, Wegovy, the sister drug of Ozempic, would have a similar impact.