Danish health authorities said on Monday they would ask the European Union's drug regulator to review the findings of two Danish studies linking Novo Nordisk's popular diabetes drug Ozempic to a rare sight-threatening eye condition.

The two studies conducted by University of Southern Denmark (SDU) found that Ozempic more than doubles the risk of NAION, or non-arteritic anterior ischemic optic neuropathy, for Type 2 diabetes patients.

The findings could add to concerns raised by an American study published earlier this year.

The Danish Medicines Agency asked the European Pharmacovigilance Risk Assessment Committee (PRAC) to review the findings.

Novo Nordisk said in a statement that: "After a thorough evaluation of the studies and Novo Nordisk’s internal safety assessment, Novo Nordisk is of the opinion that the benefit-risk profile of semaglutide remains unchanged." It added that patient safety was a top priority.

The number of NAION cases in Denmark has increased since Ozempic was introduced on the Danish market in 2018, according to Jakob Grauslund, professor in eye diseases at SDU.

"According to our study, the number being affected is fortunately lower than the American study shows, but there is still a doubling in the number of cases of NAION among those people who take Ozempic," said Grauslund.

Scientists estimate that there could be between 1.5 and 2.5 additional cases per 10,000 treated people in one year.

The Danish studies looked at possible side effects of the active ingredient semaglutide, which is found in Ozempic and belongs to a class of medications known as GLP-1 receptor agonists.

NAION is an irreversible disease that develops due to insufficient blood flow to the optic nerve and can cause sudden painless loss of vision and visual field defects.

The first Danish study was based on results from 424,000 Type 2 diabetics, where a quarter was treated with Ozempic and the rest with other diabetes-drugs.

The second Danish study involved data from 44,517 Danish diabetic patients who received Ozempic between 2018 and 2024, and 16.860 Norwegians who were treated with Ozempic between 2018 and 2022.