As public interest grows in new diabetes and weight loss drugs like semaglutide and tirzepatide, reports of serious eye-related complications are increasing. A July 2024 study published in JAMA Ophthalmology linked semaglutide — the active ingredient in Ozempic (for diabetes) and Wegovy (for weight loss) — to a rare eye condition known as non-arteritic anterior ischemic optic neuropathy (NAION). This condition occurs when blood flow to the optic nerve is blocked, causing sudden, painless vision loss in one eye.
In February of this year, another study in the same journal connected the use of semaglutide or tirzepatide — found in Mounjaro (for diabetes) and Zepbound (for weight loss) — with NAION and optic neuritis, or inflammation of the optic nerve. One patient even experienced a retinal vein occlusion at the back of the eye, a condition called paracentral acute middle maculopathy.
Now, a new study suggests that semaglutide may double the risk of developing neovascular age-related macular degeneration (nAMD), the most common cause of blindness after age 60 in Europe and the U.S. Neovascular AMD involves the growth of abnormal blood vessels beneath the macula, the central part of the retina responsible for sharp vision.
“Neovascular AMD is less common than other forms of macular degeneration but accounts for nearly all cases of sudden, irreversible loss of central vision,” explains Dr. Anastasios-I. Kanellopoulos, MD, ophthalmic surgeon, founder and scientific director of LaserVision Institute, and Professor of Ophthalmology at New York University.
Additional research has shown that semaglutide may also be associated with sudden changes in vision, such as blurriness, and could potentially worsen diabetic retinopathy.
While these findings suggest potential risks, experts emphasize that GLP-1 receptor agonists like semaglutide and tirzepatide have significantly improved outcomes for patients with type 2 diabetes, especially those who are overweight or obese. These drugs help control blood sugar and weight and reduce cardiovascular risks. However, clinical trials have revealed some adverse effects, including rare ocular complications.
Although these complications appear to be rare, the widespread use of these medications means the number of reported eye-related incidents is rising quickly.
Scientists are still unsure why some people develop eye problems while taking GLP-1 agonists. Some theories include rapid glucose level changes, direct drug effects on the eyes, or a combination of factors such as age, duration of treatment, and pre-existing vascular conditions.
“Currently, available data show rare associations, not causation. Many questions remain, which is why intensive studies are ongoing,” says Dr. Kanellopoulos.
Patients should not stop taking these medications out of fear without consulting their doctor. Those starting treatment should consider a preventive eye exam and follow-up guidance from an ophthalmologist. Anyone experiencing vision changes while on GLP-1 therapy should consult an eye specialist immediately, as early diagnosis and treatment can effectively manage many of these complications.