FDA notes potential risk of vision loss associated with GLP-1 drugs: What weight-loss drug users should know

The US Food and Drug Administration (FDA) has warned of a potential increased risk of a rare eye disease that can cause sudden and permanent vision loss in patients taking glucagon-like peptide-1 receptor agonist (GLP-1 RA) drugs, widely used to treat type 2 diabetes and obesity.

The condition, known as non-arteritic anterior ischemic optic neuropathy (NAION), can cause sudden, painless loss of vision in one eye. The FDA said patients may suffer acute vision damage, including permanent vision loss, and urged those taking the drugs to monitor for symptoms.

Based on a comprehensive safety review, the agency requires manufacturers of all GLP-1 RA drugs to include information about the potential increased risk of NAION in the “Warnings and Precautions” section of their product labels.

GLP-1 drugs mimic the action of the natural hormone released by the gut. The hormone helps regulate blood sugar levels after a meal and acts on parts of the brain responsible for controlling appetite and food intake.

These drugs are widely prescribed to people with type 2 diabetes and those who want to lose excess body weight and maintain long-term weight loss. Some drugs in the class are also approved to reduce the risk of serious cardiovascular events, including heart attacks, strokes and death, in eligible adults.

Other approved uses include reducing the risk of worsening kidney disease in some patients with type 2 diabetes, treating moderate to severe obstructive sleep apnea in obese adults, and treating metabolic dysfunction-associated steatohepatitis (MASH) with moderate to advanced liver scarring.

What is NAION and what are its symptoms?

NAION occurs when blood flow to the front part of the optic nerve, known as the optic disc, is reduced. Although the exact underlying cause is not fully understood, this condition can lead to sudden vision loss.

According to the FDA, symptoms can include a sudden, painless loss of vision in one eye that patients may first notice upon waking. Other warning signs include blurred vision, blind spots, tunnel vision, color distortion, and reduced central visual acuity, including hazy or blurry spots.

The agency advised patients to contact their healthcare professionals immediately if they experience any of these symptoms.

Patients who experience an NAION event should consult with their physicians about whether to continue or discontinue GLP-1 RA medications.

How significant is the risk?

An analysis of 126 randomized controlled clinical trials involving 134,253 participants by the FDA found a higher incidence of NAION in patients treated with GLP-1 RAs compared with those receiving placebo or other non-GLP-1 hypoglycemic agents.

The analysis identified 15 probable cases of NAION, including 10 among GLP-1 RA users and five among placebo patients. No cases were identified among participants receiving other non-GLP-1 RA glucose-lowering medications.

The incidence was 6.4 cases per 100,000 person-years among RA GLP-1 users compared with 3.8 cases per 100,000 person-years in the control group.

For context, the reported incidence of NAION in the general population is between 2.3 and 10.2 cases per 100,000 people per year in adults over the age of 50, based on the published literature.

The FDA also conducted a retrospective study using its Sentinel Real-World Evidence Data Enterprise that examined adults with type 2 diabetes who started GLP-1 RAs or other commonly prescribed diabetes medications between 2019 and 2024.

The study found NAION rates of 30-32 cases per 100,000 person-years among GLP-1 RA users, 31 among those using SGLT-2 inhibitors, and 26 among patients using DPP-4 inhibitors.

While the study did not find a statistically significant increase in the risk of NAION among GLP-1 RA users compared with SGLT-2 inhibitor users, it did find an increased risk compared with patients using DPP-4 inhibitors.

What should patients and doctors know?

The FDA stated that cases of NAION have been reported with all currently marketed GLP-1 RA products. He also noted that people with a history of NAION face an increased risk of recurrence, while those who have had the condition in one eye are at greater risk of developing it in the other eye.

Other potential risk factors include smoking, diabetes, high blood pressure, sleep apnea, anemia, and kidney disease.

The agency recommended that health care professionals inform patients of the potential risk and instruct them to immediately report sudden, painless vision loss, visual field defects, or other visual disturbances in one eye.

Physicians should promptly refer patients with suspected NAION to an ophthalmologist for evaluation. They should also consider discontinuing GLP-1 RA in patients who develop this condition unless the benefits of continued treatment clearly outweigh the risks.

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