Physician–scientists at the University of Utah’s John A. Moran Eye Center have published an investigatory review of nine patients who experienced vision complications while taking popular semaglutide and tirzepatide drugs prescribed for diabetes and weight loss.

The researchers describe patients taking the drugs who developed three potentially blinding eye conditions impacting the optic nerve, which carries visual information to the brain. Seven patients experienced nonarteritic anterior ischemic optic neuropathy (eye stroke), one had papillitis and one had paracentral acute middle maculopathy.

This review, coupled with the latest research in the field, led the authors to hypothesize that rapid changes in blood sugar induced by these drugs, rather than a toxic effect of the drugs, may contribute to these complications.

The findings are published in JAMA Ophthalmology. Co-authors include researchers from the University of Minnesota, the State University of New York at Buffalo and West Virginia University Hospitals.

“This review was not conducted in any way that we can say these drugs caused the complications,” said lead author Bradley Katz, a professor in the U’s Department of Ophthalmology & Visual Sciences. “Further studies are needed to test our hypothesis. However, this is an important issue for ophthalmologists as we monitor the usage of these drugs and how to best be in communication with our patients about them.”

Semaglutide is the active ingredient in Ozempic, Wegovy and Rybelsus, while tirzepatide is the active ingredient in Mounjaro and Zepbound. Nearly 2% of the U.S. population received a prescription for semaglutide in 2023.

A 2024 study suggested a possible connection between semaglutide use and increased risk for eye stroke, prompting the American Academy of Ophthalmologists to alert physicians and patients. An ongoing five-year study is examining the effect of semaglutide on eye disease in people with Type 2 diabetes.

“Because of the association of semaglutide with a temporary worsening of diabetic retinopathy, the increased incidence of diabetic macular edema, and the concern that rapid correction of hyperglycemia could induce papillitis, physicians prescribing this medication to their patients with type two diabetes should consider a drug regimen that more gradually lowers HbA1C level,” wrote the authors.

Katz said patients taking the drugs under the care of their doctor should not stop taking them. However, if they have a sudden loss of vision, they should stop taking the drug and see a doctor immediately.