GLP-1 Receptor Agonists and vision risk

Millions of Americans—roughly 6% of the U.S. adult population—take glucagon-like peptide-1 receptor agonists (GLP-1RAs) for chronic diseases or weight loss. These medications can be associated with significant ocular complications, according to a new clinical report by the AOA’s Evidence-based Optometry Committee. 

Among the rare ocular side effects of GLP-1RAs is non-arteritic anterior ischemic optic neuropathy (NAION), which can cause permanent loss of vision, states the report, “Glucagon-like Peptide-1 Receptor Agonists and Ocular Health: Guidance for Optometric Practice.” The report was first presented at the 2025 Optometry's Meeting® | 5th World Congress of Optometry and is meant to provide critical guidance to doctors of optometry treating patients on GLP-1RAs. 

“There is a low risk of [serious ocular side effects],” says co-author Andrew Morgenstern, O.D., director of the AOA’s clinical resources group. “But a low risk of a big number is a big risk. If it happens to you, it’s a problem.” 

The ocular risks of GLP-1RAs 

While GLP-1RAs are “very positive and transformative pharmaceutical agents for chronic disease management,” the report states, they have been associated with exacerbation of age-related macular degeneration, progression of diabetic retinopathy, and, most seriously, NAION. “These drugs are outstanding,” Dr. Morgenstern says. “They help so many people. The vision complications are rare, and more research needs to be done.” 

NAION is a very rare side effect of semaglutide (Ozempic), affecting up to 1 in 10,000 patients, according to the report. Large epidemiological studies estimate that semaglutide use is associated with a two-fold increased risk of NAION. 

It is not completely clear why semaglutide is associated with NAION, but researchers have a theory, Dr. Morgenstern says. It could be that, when the drug causes a quick drop in blood sugar, the resulting chemistry change causes blood vessels to the optic nerve to be cut off. Small vessel disease of not only the heart but also the eye is an evolving field of research. As technology to evaluate improves, the likelihood of understanding this phenomenon will as well. 

A small cup-to-disc ratio is the strongest risk factor for NAION. Other risk factors, including diabetes, hypertension, hyperlipidemia and obstructive sleep apnea, are some of the very reasons why a patient might start taking a GLP-1RA. 

Common signs of NAION include: 

1. Sudden, unilateral painless loss of vision 
2. Visual field defect (usually altitudinal) 
3. Blurred vision 
4. Dyschromatopsia (new onset impairment or loss of color vision) 
5. Relative afferent pupillary defect 
6. Optic disc swelling with or without hemorrhages 

How doctors of optometry can help 

While GLP-1RAs can significantly improve cardiovascular and diabetes symptoms, patients with preexisting ocular disease might be at increased risk. “A baseline and follow-up eye exam ensures that ocular risk factors are balanced against systemic gains,” the report states. 

A patient starting a GLP-1RA—especially if they have diabetes or age-related macular degeneration— should have an in-person, comprehensive, dilated eye examination either within the 12 months prior to starting therapy or a baseline examination within one month of initiating therapy, according to the report. 

Patients on GLP-1RAs are considered “at-risk,” meaning they also should: 

1. Follow more frequent reexamination intervals 
2. Receive individualized risk counseling regarding ocular risks 
3. Get collaborative care with providers managing their diabetes and other systemic conditions 
   

“Doctors of optometry have to be aware,” Dr. Morgenstern says. “If patients present with [NAION], they should be discontinued from the medicine immediately, and their whole health care team should be consulted.”