Last Monday, the US Food and Drug Administration (FDA) informed patients and healthcare professionals about a possible increased risk of a serious eye condition associated with the use of GLP-1 receptor agonist drugs, indicated for weight loss and diabetes, better known as the Ozempic family.
The FDA has required that drugs in this class, such as Eli Lilly's Mounjaro and Zepbound and Novo Nordisk's Ozempic and Wegovy, include information in the "warnings and precautions" section of their labeling about the possible increased risk of developing non-arteritic anterior ischemic optic neuropathy (NAION).
This has happened after a review of published observational studies that evaluated the association between GLP-1 receptor agonists and non-arteritic anterior ischemic optic neuropathy. Methodologically rigorous studies consistently pointed out a higher risk of neuropathy in patients with type 2 diabetes mellitus who started treatment with drugs from the Ozempic family, compared to those who started treatment with others, based on DPP-4 inhibitors or SGLT-2 inhibitors. These findings were generally consistent with the results obtained by the FDA from the analysis of clinical trials and the Sentinel study.
The US agency has reported cases of NAION associated with all products in the antidiabetic and antiobesity class that are currently marketed. The FDA concluded that there is a possible increased risk of this rare ocular effect in patients using GLP-1RAs. In light of these findings, the agency requires marketing authorization holders (Eli Lilly and Novo Nordisk) to include information on the risk of neuropathy in the "Warnings and Precautions" section of the labeling of all drugs in the AR-GLP-1 class.
What is the associated ocular effect?
NAION develops from insufficient blood flow to the optic nerve and causes sudden, painless loss of vision in one eye. This is a rare condition that can cause an acute, painless decrease in vision in one eye, potentially causing permanent vision loss. It is the second most common cause of blindness due to damage to the optic nerve, after glaucoma.
Symptoms may occur upon waking, such as blurred vision or the absence of parts of the visual field (visual defects such as blind spots or tunnel vision), color distortion, and reduced central visual acuity (for example, the appearance of blurred or diffuse spots), the FDA states in its warning note.
A known side effect
This is not a new side effect. Already in 2024, in the midst of the boom in the use of these drugs, a study published in JAMA Ophthalmology focused on ocular sequelae. The article warned that users of this medication could be at greater risk of suffering from a vision-threatening eye condition. The rate of nonarteritic anterior ischemic optic neuropathy, or NAION, was 8.9% for those taking semaglutide for type 2 diabetes, compared with 1.8% for patients taking non-GLP-1 diabetes medications.
The JAMA publication reported that among those who were prescribed semaglutide for overweight or obesity, the rate of the eye condition was 6.7%, compared to 0.8% of those who received other types of weight-loss medications. This was a 36-month observational study involving 710 adults with type 2 diabetes and 979 taking weight-loss medications.
After taking into account patients' other risk factors for the disease, such as high blood pressure and obstructive sleep apnea, GLP-1 drug use is associated with a more than four-fold increased risk of NAION in those receiving it for diabetes and a more than seven-fold increased risk in patients taking it for obesity.
What does the FDA recommend to patients who take them?
Patients and prescribers should be aware that the use of GLP-1 receptor agonists may lead to an increased risk of developing this type of optic neuropathy. Patients should contact their healthcare professional immediately if they experience any of these symptoms.
If a patient has suffered an episode of NAION, they should consult with their healthcare professional about whether to continue treatment with GLP-1 or discontinue it.
Europe and Spain already warned of this side effect
In June 2025, the Spanish Agency for Medicines and Health Products (Aemps) issued a report on the risk of non-arteritic anterior ischemic optic neuropathy in patients treated with semaglutide, the active ingredient in the medicines Ozempic, Rybelsus and Wegovy, used in the treatment of type 2 diabetes mellitus and obesity.
The Pharmacovigilance Risk Assessment Committee (PRAC) of the European Medicines Agency (EMA) has reviewed the risk of developing this neuropathy, an ocular condition that can cause sudden vision loss, associated with the use of semaglutide.
