A week after a study connected Ozempic and Wegovy to an eye condition that can cause partial blindness, two ophthalmology organizations said they have "been aware of other vision changes for some time."
Changing sugar levels can affect the shape of the eye's lens, according to the American Academy of Ophthalmology and North American Neuro-Ophthalmology Society. Because of this, semaglutide, the active ingredient of Type 2 diabetes drug Ozempic and weight loss medication Wegovy, might lead to blurry vision.
The ophthalmology groups said previous studies have also found that semaglutide can exacerbate diabetic retinopathy and macular complications.
"The medical community has been aware of other vision changes with semaglutide for some time," the organizations said in a July 8 joint statement. However, the research associating the drug to non-arteritic anterior ischemic optic neuropathy is the first of its kind.
The condition restricts blood flow to the optic nerve, which causes sudden, painless loss of vision in one eye, the statement said. The research did not confirm a causal relationship between the medications and NAION, but it identified a potential link.
Researchers from Somerville, Mass.-based Mass General Brigham and Boston-based Harvard Medical School, conducted the study, which analyzed about 1,700 patient medical records at a large eye hospital. The data spanned from 2017 to 2023.
Compared to patients not taking semaglutide, 17 of 200 diabetic patients developed NAION, and 20 of 361 obese patients also experienced the condition. These rates were four and seven times higher, respectively, than the non-semaglutide group.
"The subjects in this study were either overweight or obese or had Type 2 diabetes. People who have diabetes are already at risk of NAION," the organizations said. "Other risk factors for NAION include heart disease, history of heart attack, high blood pressure and sleep apnea" — health risks that also are tied to diabetes and obesity.
In response to the study, Novo Nordisk, the manufacturer of Ozempic and Wegovy, said it takes adverse event reports seriously.
The ophthalmology groups said they recommend patients continue taking the medications unless they experience a sudden vision loss.
When comparing these results to other data on temporary vision problems, the ophthalmology organizations said: "Could a similar phenomenon be at play in this study? Could the ability of semaglutide to rapidly reduce glucose levels and blood pressure cause NAION and not the drug itself? It's unknown. Only further research can answer that question."