Taking a popular diabetes drug called Semaglutide, sold under brands like Ozempic, Wegovy and Rybelsus, may face small but important risks of their vision, according to new research. Semaglutide is often used to help manage blood sugar and lose weight. But after reports linking it to a rare eye condition, doctors have become increasingly concerned that a sudden and permanent loss of vision due to damage to the optic nerve, the cable that sends visual information from the eyes to the brain.
A group of scientists led by Professor Anton Pottegård of the University of Southern Denmark and the Norwegian School of Public Health explored this possible connection. Their study, published in the Journal of Diabetes, Obesity, and Metabolism, examines national health records in Denmark and Norway. They studied people who started using Semaglutide and compared it with others who took another diabetes medication that helped clear sugar from the body through urine.
People who find Semaglutide are nearly three times more likely to occur compared to other medications. Even so, the actual number of cases is very small. This means that although this is serious, it rarely happens and the overall risk for any individual remains low.
The results of both countries are similar and there is no big change when tested in different ways. “Our study confirms that the use of semifluidine is associated with an increased risk of non-arterial pre-ischemic neuropathy, a loss of vision, not caused by inflammation, but due to a decrease in blood flow to the eye’s nerves, but with a lower absolute risk,” said Professor Pottegård. He also noted that without switching to another drug, there is a higher risk among people living in the same treatment.
Some studies have also looked at people who use Semaglutide for weight loss instead of diabetes. Although some cases of vision loss were also found in the group, it was not enough to draw any clear conclusions. “While our findings do not rule out the possibility of an increased risk of non-limb pre-ischemic optic neuropathy when using semaglutide for obesity, the small number of events observed suggests that any potential risk may have a limited absolute magnitude,” Professor Pottegård added.
Professor Pottegård’s team used reliable national data and careful research design, which is how to conduct research plans to ensure fairness. They examined hospital and prescription records, including only relevant cases. Most people who experience this vision loss end up in the hospital, so the researchers believe they include almost all cases in their study.
Professor Pottegård explained: “Our findings support the use of half-rupeptide for type 2 diabetes with more than triple the hazard ratio of non-arterial pre-ischemic optic neuropathy.” The hazard ratio is a measure used to compare the frequency of one group of health events, while over time, one group of occurrences with another group of occurrences. “However, in half-rupee users, the absolute risk of this condition remains low. The association analysis between obesity and non-arterial pre-ischemic optic neuropathy is not yet conclusive.”
Professor Pottegård and colleagues urged caution when explaining the results. This type of study does not prove that semaglutide causes the condition, but only shows that the two seem to be linked. They also pointed out that the number of vision loss cases is too small to understand who may be at greater risk.
Even with these limitations, this study adds to growing efforts to better understand the true security of Semaglutide. An earlier study attracted similar attention but focused only on patients referring to special ophthalmic tests, which may not reflect the average user. The current study provides a broader understanding by including everyday users from the entire population.
The use of semaglutide is becoming more common and is not only used to manage diabetes, but also as a weight loss agent. This makes it even more important to understand any possible risks. Professor Pottegård said that if there is a risk, it must be weighed for its known benefits to Semaglutide to help manage long-term health conditions related to blood sugar. More research is needed to see if the same pattern appears among people who use the drug to lose weight and to explore whether some people are more vulnerable than others.
Journal Reference
Simonsen E., Lund LC, Ernst MT, Hjellvik V., Hegedüs L. , Hamann S., Jørstadø.k., Gulseth HL, Karlstadø. , Pottegård A. Medrxiv, 2024. doi: https://doi.org/10.1101/2024.12.09.24318574
Image reference
http://www.chemist-4-u.com
About the Author
Professor Anton Pottegård He is a clinical pharmacist and drug ePIDEMIXOSTS at the University of Southern Denmark. With his background in pharmacy and a PhD in drug epidemiology, he leads research focusing on the long-term effects of drug safety, real-life medical use, and routine prescription treatments. His work often draws on large health data to identify patterns and risks of medication use in the population. Professor Pottegård has made extensive contributions to public health by identifying the potential side effects of widespread use of drugs, helping guide safer prescription practices. He has participated in international cooperation and consultative roles related to medical monitoring and regulation. He is known for combining rigorous science with accessible communication, and he plays a key role in bridging clinical evidence with everyday healthcare decisions. Through his leadership in national registry-based research, he continues to shed light on the benefits and risks of modern pharmacological therapy.
