Makers of GLP-1 drugs ordered to add warnings about rare eye condition that can lead to blindness

What the report says

The US Food and Drug Administration has told makers of several widely used GLP-1 medicines to add warnings about a rare eye disorder that can cause sudden, and sometimes permanent, vision loss. The drugs named in the BBC report include Ozempic, Wegovy, Mounjaro and Zepbound, which are used for diabetes and weight management. The condition is known as nonarteritic anterior ischemic optic neuropathy, or NAION.

According to the BBC, NAION occurs when blood flow to the optic nerve is blocked, reducing oxygen supply and leading to painless loss of vision in one eye. The FDA said it reviewed reports from people using GLP-1 drugs, along with other studies, and concluded there is an increased risk of rare NAION events among users. The agency said it is not yet clear why the medicines may be linked to the disorder.

The BBC also reported that medical groups and manufacturers urged caution in interpreting the evidence. The American Academy of Ophthalmology said the additional risk appears small and that a direct causal link has not been established. Novo Nordisk, which makes Wegovy, said the available data do not prove cause and effect. The academy advised patients not to stop treatment without medical advice and to seek prompt eye care if sudden vision loss occurs.

The report adds that GLP-1 medicines already carry warnings for other side effects, and that some earlier studies have suggested a possible association with NAION, though researchers have said more work is needed.