Another Study Links Ozempic to a Rare Eye Condition That Can Cause Vision Loss

A July 2024 study published in JAMA Ophthalmology found that semaglutide, the active ingredient in Ozempic and Wegovy, was linked to a higher risk of a rare eye condition known as “eye stroke,” or non-arteritic anterior ischemic optic neuropathy (NAION). This condition can lead to sudden vision loss.

Building on these findings, a new preprint study from Denmark and Norway has reaffirmed the association. Researchers found that people taking semgalutide were more than twice as likely to develop NAION compared to those using SGLT2 inhibitors, another type 2 diabetes medication.

Despite this, the absolute risk remains low. Only 32 cases of NAION were reported in the study, which included data from over 60,000 people.

The results surprised the researchers, said Anton Pottegård, PhD, DMSc, MSc, a co-author of the study and a professor of clinical pharmacology at the University of Southern Denmark.

Pottegård noted that his team’s investigation involved a stronger data source from the Danish and Norwegian nationwide registries, a significant expansion from the earlier U.S. study, which included 16,000 people.

Semaglutide is widely used to treat type 2 diabetes and obesity. While experts stress that the risk of NAION is rare, more research is needed to understand why semaglutide may increase susceptibility and which patients are most at risk.

What Is NAION? 

NAION is a rare eye condition that mainly affects people over the age of 50. The main symptom of NAION is a sudden loss of vision, usually in one eye, due to a lack of blood flow.

There is no treatment for NAION, and management focuses on addressing what underlying risk factors a person may have, such as diabetes, smoking, and taking certain medications.

Is the Risk Being Investigated?

Pottegård emphasized that the overall risk of NAION is low and that more research is needed to understand if all glucagon-like peptide 1 (GLP-1) agonists could increase a person’s risk of developing the condition.

“There’s certainly a need for research into not only why this happens, but also what patients are at risk of experiencing it,” said Pottegård.

Reuters reported that the European Union drug agency plans to investigate potential NAION risks related to semaglutide. Novo Nordisk, the company that makes Ozempic, told Reuters that patient safety is their top priority.

“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,” the company said.

Should People Stop Ozempic If They’re Worried About NAION?

People who are taking semaglutide should not be overly worried about the study findings because NAION cases are still extremely rare, said Gitanjali Srivastava, MD, a professor of medicine and the Medical Director of Obesity Medicine at Vanderbilt University Medical Center.

“At our obesity center, we see about 10,000 new patients per year, and that has never happened to any one of my patients,” Srivastava told Verywell. “For the most part, this medication is safe, it’s low risk, but patients should weigh the risk versus benefits.”

For some people undergoing diabetes treatment, Srivastava said that symptoms of retinopathy—or damage to the retina—may get worse temporarily because the eye tissue is very delicate. This isn’t the same as NAION, which causes permanent vision loss.

“If you have poorly controlled diabetes, and you treat the diabetes and it improves rapidly, all of a sudden, you see a little bit of worsening of the retinopathy … before it gets better,” said Srivastava.

GLP-1 drugs like semaglutide can actually help with inflammation, though—so some people taking them may get some eye health benefits.

“Semaglutide actually is known for its anti-inflammatory properties,” said Srivastava. “I have lots of patients who have improvement of their neuropathic or neuropathy symptoms on the semaglutide.”