A recent study has raised concerns over potential vision-related side effects in individuals taking GLP-1 weight loss medications, though researchers caution that a direct link remains unconfirmed.

Published in JAMA Ophthalmology, the study examined nine cases of individuals who developed severe eye conditions after using GLP-1 receptor agonists, including semaglutide (Wegovy/Ozempic) and tirzepatide (Mounjaro/Zepbound). The patients, all in their 50s or 60s, were taking the medications to manage obesity or diabetes.

Among them, seven were diagnosed with nonarteritic anterior ischemic optic neuropathy (NAION), a condition where inadequate blood flow to the optic nerve results in sudden and irreversible partial vision loss. Another patient developed a maculopathy, causing blind spots, while a ninth was diagnosed with papillitis, an inflammation of the optic nerve head.

Dr. Bradley Katz, lead author of the study and a neuro-ophthalmologist at the John A. Moran Eye Center at University of Utah Health, first noted a troubling pattern when one patient suffered painless vision loss in one eye after starting semaglutide. After temporarily discontinuing the drug, the patient resumed treatment—only to experience vision loss in the other eye.

Katz then reached out to other ophthalmologists via a professional listserv, leading to the collection of the nine case reports detailed in the study.

Unclear Link Between Medications and Vision Loss

Despite these findings, researchers emphasize that it is still uncertain whether the vision problems stemmed directly from GLP-1 drug use or from underlying health conditions such as diabetes, heart disease, or obesity, which are already known to contribute to eye disorders.

Dr. Norah Lincoff, study co-author and neuro-ophthalmologist at the University at Buffalo, pointed out that similar cases of NAION have previously been associated with erectile dysfunction medications and drugs for irregular heartbeats. Additionally, she suggested that rapid reductions in blood sugar levels—a common effect of GLP-1 drugs—could, in rare cases, make the optic nerve more vulnerable.

“Are these drugs increasing the risk for an episode of visual loss? The message to patients is that we are still investigating if these medications put them at higher risk of ischemic optic nerve damage,” Lincoff stated.

Advice for Patients and Physicians

While the findings warrant further study, researchers stress that cases of vision loss associated with GLP-1 drugs are extremely rare. Patients should not panic but should remain vigilant about any changes in their eyesight.

“If a patient on one of these medications reports blurring or vision loss, they should see an ophthalmologist as soon as possible. Don’t wait,” Lincoff advised.

For individuals concerned about potential risks, alternative treatments for diabetes and weight management remain available, she added.

The study underscores the need for continued research into the potential side effects of GLP-1 medications, particularly as their popularity grows in weight loss and diabetes management.