GLP-1 Diabetes Drugs May Increase Risk of Eye Disease, Study Finds

New Concerns About Popular Medications Like Ozempic and Mounjaro

A new Canadian study has found a possible link between GLP-1 receptor agonist medications—such as Ozempic and Mounjaro—and an increased risk of a serious eye condition: neovascular age-related macular degeneration (nAMD). These drugs, commonly prescribed for type 2 diabetes and obesity, may pose a rare but notable vision risk.

The study analyzed data from over 139,000 diabetic patients aged 66 and older between January 2020 and November 2023.

What Is Neovascular Age-Related Macular Degeneration (nAMD)?

Age-related macular degeneration (AMD) is the leading cause of vision loss in adults over 50. It mainly affects central vision, while peripheral vision often remains intact. There are two types:

• Dry AMD – the more common form, with gradual onset

• Wet AMD (nAMD) – more severe, caused by abnormal, leaking blood vessels under the retina

The study found that patients taking GLP-1s had twice the risk of developing nAMD compared to those not on the medications.

“The longer patients were exposed to these medications, the greater their risk appeared to be,” said Reut Shor, a co-author and researcher at the University of Toronto.

Study Limitations and Scope

While the findings are concerning, researchers emphasize the study’s limitations:

• It was observational, not causal.

• Only included diabetic patients aged 66 and older.

• Cannot be generalized to non-diabetics using GLP-1s for weight loss.

“The absolute risk is still small,” said study author Dr. Rajeev Muni. “The incidence of nAMD rose from 1 in 1,000 to 2 in 1,000 in GLP-1 users.”

Nonetheless, the dose-response pattern suggests that longer use may increase risk, raising concern for those on extended treatment plans.

Why Might GLP-1s Affect Vision?

GLP-1 receptors are present in the retina, meaning their effects could theoretically impact any user—regardless of age or diabetes status. Still, more research is needed to understand how and why these changes occur.

Risk factors for nAMD already include conditions like:

• Chronic heart failure

• Kidney disease

• Diabetes

These often overlap with those prescribed GLP-1s, making it difficult to isolate the drugs as the sole contributor.

What Patients Should Watch For

Doctors urge patients on GLP-1 medications to monitor for symptoms of nAMD, including:

• Blurred or distorted vision

• Straight lines appearing wavy

• New blind spots or missing areas in vision

“Early detection is crucial,” said Dr. Nishika Reddy of the University of Utah. “Timely treatment can help prevent significant vision loss.”

Final Takeaway: Low Risk, But Stay Informed

Although the absolute risk of vision loss is low, diabetic patients on GLP-1 medications should be aware of the possibility of eye-related side effects. The findings aim to empower patients to stay alert to early symptoms and seek medical advice when needed.

Further clinical trials are needed to determine whether GLP-1s directly cause eye disease, and whether younger or non-diabetic users might also be at risk.