As weight-loss drugs have skyrocketed in popularity over the past couple years, news stories about potential side effects and complications have also spread widely. Aside from the well-documented gastrointestinal issues caused by semaglutide drugs—including Wegovy and its sister drug Ozempic, the latter of which is a diabetes medication prescribed off-label for weight loss—there have been reports of rarer stomach conditions, and even behavioral changes. Now, a new study has determined that drugs like Wegovy and Ozempic could potentially spike the risk of a rare eye condition that can lead to blindness.
RELATED: Ozempic Patient Shares "Psychological Effects" That Made Him Want to Quit.
Researchers from Mass General Brigham published a study on July 3 in JAMA Ophthalmolgy that looked at the risk of non-arteritic anterior ischemic optic neuropathy (NAION) for patients taking semaglutide medications like Wegovy and Ozempic.
NAION is "potentially debilitating condition that occurs from a lack of sufficient blood flow to the optic nerve," according to Penn Ophthalmology. It typically leads to vision loss in one eye, but can also cause total blindness—research has found that those who develop NAION in one eye have a 15 percent chance of it occurring to the other eye within a year.
"It is, in effect, a stroke of the optic nerve,” senior study author Joseph Rizzo, MD, director of neuro-ophthalmology at Mass Eye and Ear in Boston, told NBC News.
According to a news release, Rizzo and other Mass Eye and Ear neuro-ophthalmologists decided to conduct their study after noticing that three patients in their practice who were taking semaglutide medications had all been diagnosed with vision loss from this "uncommon optic nerve disease" in the same week.
"NAION is relatively rare, occurring up to 10 out of 100,000 people in the general population," the researchers noted in the release. "NAION is the second-leading cause of optic nerve blindness (second only to glaucoma) and it is the most common cause of sudden optic nerve blindness."
For the study, researchers looked at the records of more than 17,000 Mass Eye and Ear patients who had been treated by the health organization in the six years since Ozempic's release.
Their analysis found that people who had diabetes and had been prescribed semaglutide were over four times more likely to be diagnosed with NAION. They also discovered that those who were overweight or had obesity and had been prescribed this medication were more than seven times more likely to be diagnosed with NAION.
RELATED: Women Report New Surprising Ozempic Side Effects: "Your Body Is Going to Change."
"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," Rizzo said in a statement. "It is important to appreciate, however, that the increased risk relates to a disorder that is relatively uncommon."
The researchers also noted that there were several limitations to their study and emphasized that the results do not prove causality.
"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 explained. “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."
When Best Life reached out to Novo Nordisk, the maker of both Wegovy and Ozempic, about this new study, a spokesperson for the company pointed out that there were "key methodological limitations" in the research.
"This is a single centre, retrospective cohort study with a high risk of selection bias. This study is not designed to assess any potential causal relationship between NAION and semaglutide exposure," the Novo Nordisk spokesperson said in a statement.
They added, "Patient safety is a top priority for Novo Nordisk, and we take all reports about adverse events from use of our medicines very seriously. NAION is not an adverse drug reaction for the marketed formulations of semaglutide (Ozempic and Rybelsus for type 2 diabetes and Wegovy for obesity) as per the approved labels."
