Weight-loss medications Mounjaro and Zepbound, which contain the active ingredient tirzepatide, may lower the risk of diabetic retinopathy, a complication of diabetes that can lead to vision loss. Diabetic retinopathy occurs when high blood sugar damages blood vessels in the retina. Diabetes also increases the risk of other eye diseases, including cataracts and glaucoma.
Researchers analyzing electronic health records from 174,000 people across 70 U.S. health systems found that people with type 2 diabetes who started tirzepatide were less likely to develop new diabetic retinopathy or progress to more severe stages over one year than similar patients who used lifestyle interventions (nutrition therapy, exercise counseling) alone. For example, incident mild non-proliferative diabetic retinopathy occurred in 0.49% of tirzepatide patients versus 1.2% of the lifestyle intervention group.
Szilard Kiss, MD, an ophthalmologist at NewYork-Presbyterian/Weill Cornell Medical Center and lead author of the study, said the findings suggest patients with diabetic retinopathy may be less concerned that taking tirzepatide will worsen their condition and that they may have a reduced risk of needing laser or injection treatments typically required for severe retinopathy. Kiss is on the board of directors of Adverum Biotechnologies, which is owned by Eli Lilly, the manufacturer of Mounjaro and Zepbound.
The new study follows earlier research that raised concerns about some GLP-1 agonists. Prior studies indicated medications such as semaglutide (found in Ozempic and Wegovy) could cause temporary worsening of diabetic retinopathy in some people with type 2 diabetes. Those effects were reported as short-term, with no long-term association with increased retinopathy progression over a three-year period in the examined studies.
Experts note a likely explanation: GLP-1–based drugs, including tirzepatide and semaglutide, suppress appetite by mimicking the body’s GLP-1 hormone and improve blood sugar control. Benjamin Bert, MD, an ophthalmologist at MemorialCare Orange Coast Medical Center, noted both medication types reduce hunger and help manage glucose. Adrian Au, MD, an ophthalmologist at UCLA Health, cautioned that rapid drops in blood sugar can temporarily worsen retinopathy in people who already have advanced disease — a phenomenon seen with intensive glucose control even before GLP-1 drugs were widely used. Over the long term, better blood sugar control is associated with improved retinal outcomes, he said.
Study authors suggest tirzepatide may provide “greater improvements in insulin sensitivity, weight loss and metabolic inflammation,” which could underlie the observed association with lower retinopathy risk. However, experts emphasize the current study is observational and shows association, not proof of cause and effect. Longer-term data and randomized trials would be needed to establish causality.
Diabetic retinopathy is common: a 2021 JAMA Ophthalmology study estimated nearly 10 million people in the United States have diabetic retinopathy and that nearly 2 million have vision-threatening forms. The condition often causes only mild vision problems at first but can lead to significant vision loss. High blood sugar damages retinal blood vessels, and in severe cases the eye can develop abnormal new vessels (neovascularization) that raise eye pressure, damage the optic nerve, and may lead to blindness.
Other eye issues linked to diabetes include diabetic macular edema, cataracts, and glaucoma. Treatments for diabetic retinopathy and its complications focus on managing blood sugar and overall health and may include injections into the eye, laser treatments, and surgery. Eye drops may relieve some symptoms but do not reverse retinal blood vessel damage.
Preventive measures include maintaining good blood sugar control, managing blood pressure and cholesterol, eating a healthy diet, quitting smoking, and regular exercise. Ophthalmologists recommend that everyone with diabetes receive a dilated eye exam at least once a year. Those starting powerful glucose-lowering medications — particularly people with pre-existing diabetic retinopathy — may benefit from closer eye monitoring in the first few months of treatment. Anyone with sudden vision changes should see an ophthalmologist promptly.
While tirzepatide’s association with reduced retinopathy risk is encouraging, clinicians and patients should interpret the findings cautiously until longer-term, controlled studies confirm cause and effect.
