Last July, we wrote a blog about a study that linked the weight loss drug Semaglutide — marketed as Ozempic for weight loss and Wegovy for blood sugar concerns — to developing a rare form of blindness. In cases of nonarteritic anterior ischemic optic neuropathy (NAION), people lose vision when their optic nerve loses blood flow. The drug was tentatively linked to the condition.

When we wrote the blog, the evidence was still out. We were making people aware that it was a potential factor, but no conclusions had been drawn.

Now, the European Medicines Agency has confirmed that NAION is a very rare side effect of the medications. There is a one in 10,000 chance of the condition, but the label has to be labelled with the risk.

There is also evidence that the medications can worsen retinopathy caused by high blood sugar, damaging the blood vessels. That can cause vision loss. The medication can cause rapid blood sugar decreases that can destabilize the already-damaged blood vessels and lead to bleeding.

Two new studies were published looking at the medical data of people with blood sugar concerns. The studies involved 159,000 and 185,000 people. One of the studies found that, while Semaglutide can cause NAION, the risk might not be as bad as thought. One recent study said it only happens in 0.04 percent of people.

While the risk for NAION might not be as high as thought, the medication did increase the risk of “other optic nerve disorders.” But, overall, people taking the drug were less likely to need invasive eye treatments compared to people taking other medications for their blood sugar health.  

There are five-year clinical trials underway testing the long-term impacts of Semaglutide on blood sugar-related eye disease. Hopefully, that will clarify the risks and benefits the medication may have for vision health.

When it comes to making choices for your health, it’s all about balancing risks. Doctors should discuss NAION while talking through the possible side effects of Semaglutide. They should also monitor people for retinopathy. However, the medication can be hugely beneficial for some people, and if it could be something that would radically assist a person’s health, a potential benefit may outweigh the relatively small risk. It all depends on personal choice and circumstance.