A new study from the University of Toronto has raised concerns about a well-known diabetes and weight-loss drug.
Researchers found that older adults with diabetes who took semaglutide—a medicine sold under the brand names Ozempic and Wegovy—had more than twice the risk of developing a serious eye condition called neovascular age-related macular degeneration (nAMD).
nAMD is a dangerous form of age-related macular degeneration, the top cause of vision loss among older adults in Western countries. It is less common than the dry form but can cause quick and lasting damage to central vision.
This happens when abnormal blood vessels grow in the retina and leak fluid or blood, harming the macula—the part of the eye that allows us to see clearly and directly in front of us.
Semaglutide is part of a group of medications called GLP-1 receptor agonists. These drugs have transformed diabetes care by helping control blood sugar and even reducing heart disease risk. They are also now popular for helping with weight loss, often talked about in the media. But their possible side effects on vision had not been deeply studied.
Some early warning signs came from clinical trials, including SUSTAIN 6 and PIONEER 6, which showed more diabetic eye problems in people taking semaglutide. There have also been rare reports of optic nerve damage. On the other hand, some small lab studies suggested the drug might protect the eyes. Until now, the evidence was mixed.
In this new study, published in JAMA Ophthalmology, researchers looked at the health records of 139,002 adults in Ontario aged 66 and older between 2020 and 2023. All had diabetes. Among them, 46,334 had taken semaglutide or similar drugs for at least six months. The rest had not used these drugs at all.
Using advanced statistical methods, the researchers found that people who used GLP-1 drugs had more than double the risk of being diagnosed with nAMD. The longer they used the medication, the higher the risk. Those who had been on it for over 30 months were more than three times as likely to develop the condition.
Older age and a history of strokes or brain blood vessel issues also increased the chances of getting nAMD.
This research raises concern about the long-term eye safety of semaglutide. While it has clear benefits for managing blood sugar and aiding weight loss, this new finding could lead to changes in how doctors monitor patients using the drug, especially over long periods.
Scientists are not yet sure whether the drug itself is causing the damage, whether it’s related to diabetes, or if another factor is involved. More research is needed to understand the exact reason behind this increased risk.
For now, the researchers suggest that doctors regularly check the eye health of patients who are taking semaglutide, particularly those on the drug for more than a year. Early eye exams might help catch vision problems before permanent damage occurs.
As semaglutide becomes more widely used, this study shows the importance of keeping track of its long-term effects. Millions of people—many older and already at risk of vision issues—are taking these medications. Careful monitoring could make a big difference.
If you care about diabetes, please read studies about Potatoes: friend or foe in the battle against diabetes? and findings of This blood pressure drug may protect kidney health in people with diabetes.
For more about diabetes, please read studies about Scientists find a promising treatment for type 2 diabetes and findings of Certain type 2 diabetes treatment may bring heart risks.
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