• Posted July 3, 2024

GLP-1 Drugs Ozempic, Wegovy Linked to Rare Blinding Condition

Trendy weight-loss drugs appear to increase the risk of a rare and potentially blinding eye condition, a new study warns.

People with diabetes prescribed semaglutide (Ozempic, Wegovy) were more than four times more likely to be diagnosed with NAION, researchers reported July 3 in the journal JAMA Ophthalmology.

Further, those who were overweight were more than seven times more likely to be diagnosed with NAION, results showed.

"The use of these drugs has exploded throughout industrialized countries and they have provided very significant benefits in many ways, but future discussions between a patient and their physician should include NAION as a potential risk," said lead researcher Dr. Joseph Rizzo, director of the Neuro-Ophthalmology Service at Mass Eye and Ear in Boston.

"It is important to appreciate, however, that the increased risk relates to a disorder that is relatively uncommon,"he added in a hospital news release.

NAION typically causes sudden vision loss in one eye, without any pain, Rizzo said. It's thought to be caused by reduced blood flow to the front of the optic nerve, where the nerve meets the eye.

NAION is the most common cause of sudden blindness due to damage of the optic nerve, and is second only to glaucoma as an overall cause of optic nerve blindness, researchers said.

There currently are no effective treatments for NAION, and vision loss to the nerve damage is generally considered permanent.

However, NAION is relatively rare, occurring in about 10 out of every 100,000 people, researchers said.

They conducted the new study after noticing that three patients had been diagnosed with vision loss from NAION in just one week. All three had been taking semaglutide.

Semaglutide initially was developed to treat type 2 diabetes, as it helps control blood sugar levels. It was later approved for weight loss after researchers found that it helped control appetite and slow digestion.

For the study, researchers analyzed records for more than 17,000 Mass Eye and Ear patients treated during the six years since Ozempic was approved for diabetes treatment.

Researchers compared NAION rates in people prescribed semaglutide against those taking other diabetes or weight-loss drugs, and discovered the significant risk increases.

However, researchers noted that they aren't sure why this association exists.

"Our findings should be viewed as being significant but tentative, as future studies are needed to examine these questions in a much larger and more diverse population,"Rizzo said. 

"This is information we did not have before and it should be included in discussions between patients and their doctors, especially if patients have other known optic nerve problems like glaucoma or if there is preexisting significant visual loss from other causes," he added.

Novo Nordisk, which makes Ozempic and Wegovy in the United States, emphasized that the data in the new study doesn't establish a causal association between the use of semaglutide medications and NAION.

"Patient safety is a top priority for Novo Nordisk, and we take all reports about adverse events from the use of our medicines very seriously,"a company spokesperson told CNN.

More information

Brigham and Women's Hospital has more on NAION.

SOURCE: Mass Eye and Ear, news release, July 3, 2024; CNN