According to a new study, people who take Wegovy or Ozempic are at a higher risk of developing a rare type of blindness.
However, experts say it shouldn’t deter individuals from using the drug to treat obesity or diabetes.
Last summer, doctors at Massachusetts Eye and Ear, saw an usually high number of patients with non-arteric anterior ischemic optic neuropathy (NAION), an eye condition that causes blindness due to a lack of blood flow to the optic nerve.
A relatively rare condition, it affects up to 10 out of 100,000 individuals. However, doctors at the specialty hospital saw three NAION cases in one week. They soon realized that all three patients were taking Ozempic or Wegovy.
Looking back at previous medical records, they found that diabetics taking a semaglutide prescription were over four times more likely to be diagnosed with NAION.
Those who were obese or overweight taking the same medication were also more than seven times more likely to be diagnosed with the rare eye condition.
The risk of NAION was the highest within the first year of starting a semaglutide prescription.
The new study, which was published in JAMA Opthalmology on Wednesday, does not prove causal association regarding NAION and semaglutide medications. The number of patients was also on the low end, approximately 100 cases per year.
While Novo Nordisk, the US manufacturer of semaglutide medications, emphasized that the results from the new study was not enough to establish a causal link, they noted that they take all reports seriously as ‘patient safety is their number one priority.’
Currently, the mechanism in which semaglutide medications interact with the eyes is not entirely known. To make matters even more confusing, the cause of NAION is not entirely understood either.
However, experts do know that the condition affects the optic nerve and that there is typically no warning or symptoms before vision loss.
According to Dr. Disha Narang, the director of obesity medicine and endocrinologist at Endeavor Health, fluctuations in blood sugar levels may affect vision as it can impact the shape of the eye’s lens.
Semaglutides, which work by prompting the body to produce more insulin, has also been shown to cause temporary vision changes in previous studies. For example, it has been linked to diabetic retinopathy and damage to the blood vessels in the retina.
The FDA-approved labels for both Wegovy and Ozempic currently include vision changes, among other adverse effects. The drug manufacturer is also examining the link between diabetic retinopathy and semaglutide use in a trial, which is scheduled to finish in 2027.
For now, those who are taking the medications or are considering starting semaglutides are advised to talk to their health care practitioners about the risks and benefits, especially those with pre-existing eye conditions such as glaucoma.
