Researchers say they have uncovered a link between semaglutide — the active ingredient in Ozempic and Wegovy — and sudden vision loss.
The risk of developing nonarteritic anterior ischemic optic neuropathy (NAION) is four times higher for diabetics on semaglutide and seven times higher for people taking the drug to lose weight, according to a new study from Massachusetts Eye and Ear, a teaching hospital of Harvard Medical School.
A relatively rare condition, NAION is believed to be caused by insufficient blood flow to the optic nerve head. The result is painless but irreversible vision loss in one eye. There are no effective treatments for NAION.
NAION is not fully understood — and neither is the purported relationship between semaglutide and the optic nerve disorder.
“This study is the first, to our knowledge, to report an association between semaglutide and NAION, although the design of our study did not enable query into a causal relationship between the two,” the researchers wrote in their findings, published Wednesday in the journal JAMA Ophthalmology.
The investigation began late last summer when Mass Eye and Ear neuro-ophthalmologists noticed that three patients in their practice had been diagnosed with the disease in just one week. All three were taking semaglutide.
The researchers pored over the records of more than 17,000 Mass Eye and Ear patients treated in the six years since Ozempic was released and analyzed the rate of NAION diagnoses. They identified significant risk increases with semaglutide.
“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 Dr. Joseph Rizzo, director of the Neuro-Ophthalmology Service at Mass Eye and Ear and the study’s corresponding author.
Semaglutide was approved by the Food and Drug Administration in December 2017 to treat Type 2 diabetes and in June 2021 for adult weight loss.
Ozempic’s safety information warns that vision changes may occur. Wegovy’s potential side effects include vision changes for people with Type 2 diabetes.
These drugs and similar injectable medications that mimic appetite-suppressing hormones have skyrocketed in popularity in recent years.
The researchers say they anticipate increasing numbers of NAION cases related to semaglutide drugs even as they acknowledge limitations of their study.
They noted that Mass Eye and Ear patients commonly have rare eye diseases, the number of NAION diagnoses recorded in the six-year study period is relatively small, and they could not tell if the patients stopped taking semaglutide.
“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.
