Recent studies have uncovered a frightening association between the popular diabetes and weight loss drugs, Ozempic and Wegovy, with a rare eye disorder that may cause blindness.

A study, published in the medical journal JAMA Ophthalmology, reported that individuals on those drugs containing semaglutide have a much larger percentage chance of acquiring NAION, or, more precisely known by its acronym, non-arteritic anterior ischaemic optic neuropathy.

This is defined by a lack of flow through the optic nerve, suddenly damaging one’s vision since that nerve has more than one million strands. NAION is a rare condition, affecting only 2 to 10 people per 100,000. It is the second leading cause of optic nerve blindness, and there is currently no effective cure.

The study revealed that those using semaglutide for diabetes were four times more likely to develop NAION than those not using the drug. Those using it for weight loss had even greater risk-more than seven times higher.

“To be perfectly clear, I would not take my findings and use them to recommend that patients stop taking their medications,” says Dr Rizzo. “Our finding was really the first possible significant negative finding with these drugs. It may just merit extra caution in the consideration between doctors and patients about who may use this medicine.”

According to the study, semaglutide is linked to a seven-fold increased risk of NAION when taken to treat obesity and a four-fold increased risk when used to treat type 2 diabetes.

Among the 710 patients with Type 2 diabetes, semaglutide users had an 8.9% chance of developing NAION, while those on other medicines had a 1.8% chance.

The rate of NAION development was 6.7% for patients administered semaglutide for weight loss and 0.8% for patients on other medicines.