A widely used diabetes and weight-loss medicine is now under closer review after a large new study raised concerns about its possible effects on eye health.
Researchers from the University of Toronto have found that older adults with diabetes who took semaglutide, a drug sold under the brand names Ozempic and Wegovy, had more than twice the risk of developing a serious eye disease called neovascular age-related macular degeneration, or nAMD.
Age-related macular degeneration is one of the leading causes of vision loss in older adults, especially in Western countries. There are two main types of this disease: dry and wet. The dry form is more common and usually progresses slowly.
The wet form, also called neovascular AMD, is less common but far more dangerous. It can lead to quick and lasting damage to central vision, which is the part of vision people use for reading, driving, and recognizing faces.
In nAMD, abnormal blood vessels grow underneath the retina at the back of the eye. These vessels are fragile and can leak blood or fluid. When this happens, the macula—the small but important area of the retina responsible for sharp, detailed vision—becomes damaged. Without treatment, people can lose their central vision permanently.
Semaglutide belongs to a group of drugs known as GLP-1 receptor agonists. These medicines help lower blood sugar levels in people with type 2 diabetes by improving how the body releases insulin and controls appetite.
They have also been shown to reduce the risk of heart disease in some patients. In recent years, semaglutide has gained even more attention because of its strong effect on weight loss. Many people without diabetes now use similar drugs to help manage obesity.
Although the drug has clear benefits, its long-term effects on the eyes have not been fully understood. Earlier clinical trials, including SUSTAIN 6 and PIONEER 6, showed that some people taking semaglutide experienced more diabetic eye problems compared to those not taking the drug.
There have also been rare reports of damage to the optic nerve. However, some small laboratory studies suggested that the drug might even have protective effects on eye tissue. Because of these mixed findings, experts have not been certain whether semaglutide increases or decreases eye risks.
In the new study, which was published in JAMA Ophthalmology, researchers examined health records from Ontario, Canada. They reviewed data from 139,002 adults aged 66 and older between 2020 and 2023.
All of the participants had diabetes. Among them, 46,334 people had taken semaglutide or similar GLP-1 drugs for at least six months, while the remaining participants had not used these medications.
The researchers used advanced statistical tools to compare the two groups as fairly as possible. They found that people who used GLP-1 drugs were more than twice as likely to be diagnosed with nAMD compared to those who did not use the drugs.
The risk appeared to increase with longer use. Patients who had been taking the medication for more than 30 months were more than three times as likely to develop the condition.
The study also found that certain factors raised the risk even more. Older age was one important factor. A history of stroke or other blood vessel problems in the brain also increased the chance of developing nAMD. These findings suggest that people who already have circulation problems may need extra care.
Despite these results, scientists say it is still too early to conclude that semaglutide directly causes the eye disease. It is possible that the increased risk is linked to diabetes itself or to other health conditions common in older adults.
There may also be other factors that were not measured in the study. More research is needed to understand the exact reason behind the association.
For now, the researchers recommend that doctors closely monitor the eye health of patients who are taking semaglutide, especially those who have been using it for more than a year. Regular eye examinations may help detect early signs of macular degeneration before serious damage occurs. Early treatment can sometimes slow or limit vision loss.
As semaglutide becomes more widely used for both diabetes and weight loss, understanding its long-term safety is increasingly important. Millions of people, many of them older and already at risk for vision problems, rely on this medication.
Careful follow-up and further studies will help ensure that patients receive the benefits of treatment while minimizing possible harm.
If you care about weight loss, please read studies about orange that could help obesity, and a berry that can prevent cancer, diabetes and obesity.
For more health information, please see recent studies about ginger’s journey in weight management ,and green tea: a cup of weight loss.
Copyright © 2026 Knowridge Science Report. All rights reserved.
