Ozempic Linked to Rare ‘Eye Stroke’ Risk

People who take semaglutide—the active ingredient in Ozempic and Wegovy—may have a higher risk of a rare eye condition called nonarteritic anterior ischemic optic neuropathy (NAION), which can result in loss of vision, according to a recent study published in JAMA Ophthalmology.

The retrospective study analyzed data from 16,827 patients and found that patients with type 2 diabetes who used semaglutide had a 4.3% higher risk of developing NAION than those on other medications.

Among the 979 patients with obesity or overweight, those who were prescribed semaglutide had a 7.6% higher risk of developing NAION than those on other medications.

NAION is sometimes referred to as an “eye stroke.” It occurs when there’s reduced blood flow to the optic nerve, and it can lead to sudden blindness, sometimes at the edge of one’s eyesight. There’s no consensus on what causes this condition, and there’s no definitive treatment. Typically, people who have diabetes, sleep apnea, and high blood pressure are at higher risk of this condition.

Jovi Boparai, MD, co-founder and CEO at CorneaCare and a practicing ophthalmic surgeon who was not involved in the study, said the results were surprising because GLP-1 drugs are supposed to manage diabetes, a risk factor associated with NAION.

“We see [NAION] commonly in individuals who have what we call circulatory problems, where the blood circulation isn’t as it should be. And one of the things with managing diabetes is that it should theoretically, over time, improve your circulation,” Boparai told Verywell.

This study only showed a correlation between semaglutide use and NAION rather than causation, indicating that more research is needed before a definitive connection can be confirmed.

Howard R. Krauss, MD, director of neuro-ophthalmology at the Pacific Neuroscience Institute, said a very small percentage of the population has a “disc at risk,” which is a crowded optic disc that predisposes people to certain eye conditions, including NAION. He said patients should keep in mind that the incidence rate in the study is low.

“Even if this drug does increase the risk—and it’s not yet been proven—by fourfold or eightfold, it’s still a rare condition,” Krauss said.

Should Patients Worry About Eye Stroke Risk From Semaglutide?

Ella Faktorovich, MD, an ophthalmologist and the founder and director of Pacific Vision Institute, said that the study is already coming up in conversation with her patients.

“I had a patient who called me and I did her LASIK surgery about three years ago. She called me, having seen this study, and was asking me whether it’s okay for her to keep taking the medication that has helped her lose 20 pounds,” Faktorovich told Verywell.

Faktorovich said it’s important to compare the risk of NAION to the benefits of semaglutide. If someone’s at a higher risk of developing optic neuropathy but could benefit tremendously from weight loss or diabetes management, then semaglutide is still a useful drug.

“On the other hand, if somebody has a smaller amount of weight to lose, for example, then they should probably consider possible side effects of the medication and discuss with their doctor, the pros and cons and the risk profile for them,” Faktorovich added.

Krauss echoed the sentiment and said the study is not a cause for alarm for patients on semaglutide.

“While there may be 6,000 to 10,000 cases of NAION in the United States each year, there are about 800,000 strokes and 800,000 heart attacks in the United States each year,” Krauss said. “So you have to balance one versus the other by whatever means you do it, whether it be by diet or exercise, or medication. It’s healthier to get better control of your diabetes and healthier to lose the weight.”

What Are the Symptoms of an Eye Stroke?

According to Boparai, if you have type 2 diabetes, you should get a dilated eye exam once a year.

“The reason for that is because just how type 2 diabetes can impact your blood vessels through the body, causing circulatory issues, they can do the same thing in the eyes,” Boparai said.

An eye stroke usually happens with little to no warning. People with NAION may notice a sudden vision loss in one eye upon waking up in the morning or experience blurry and worsening vision over the course of a few hours or days.

Krauss added that NAION is generally painless, but it’s important to react in the same way you would if you were having a stroke in another part of the body: Go see a doctor immediately.

“A sudden, abrupt change in your vision should trigger a visit to the emergency department already or, at a minimum, a phone call to your eye doctor in terms of instructions as to what you should do,” Krauss said.