Ozempic and Vision Loss

Reports of vision loss from drugs like Ozempic and Mounjaro are surfacing as more people take Glucagon-like peptide-1 Receptor Agonists (GLP-1 RA) to lose weight. Semaglutide GLP-1 RA drugs were the first to appear on the market with the approval of Ozempic and Wegovy. Ozempic was originally approved for type 2 diabetes and Wegovy for chronic weight management in obese patients with at least one weight-related comorbidity (hypertension, type 2 diabetes, or dyslipidemia). Tirzepatide GLP-1 RA drugs for type 2 diabetes and weight management, Mounjaro and Zepbound, soon followed. Other GLP-1 RA medications include exenatide (Byetta and Bydureon), liraglutide (Victoza and Saxenda), dulaglutide (Trulicity), and lixisenatide (Adlyxin), which are used for type 2 diabetes, with some, like Saxenda, also approved for weight management.

Nonarteritic Anterior Ischemic Optic Neuropathy (NAION), a rare but serious eye condition that causes sudden vision loss, has been identified at an increased frequency in people using Ozempic, Wegovy, Mounjaro, and Zepbound, which are semaglutide and tirzepatide GLP-1 RA medications. NAION occurs in up to 10 out of 100,000 people and is the second-leading cause of optic nerve blindness. It results from reduced blood flow to the optic nerve head, causing permanent, painless vision loss. There is little chance of improvement, and no treatment exists.

In a study from Massachusetts General Brigham, diabetics prescribed semaglutide were more than four times more likely to be diagnosed with NAION than people with diabetes who did not take semaglutide. Other studies are also showing an association between these drugs and optic nerve injury. Recent news reports highlighted several patients that developed NAION and went blind after using Ozempic and Mounjaro. One man developed it after an increase in his Mounjaro dosage, and another man developed it while on Ozempic. For these people, the loss of vision was catastrophic.

GLP-1 receptors are found throughout the eye, including the retina, the optic nerve, and the ocular vasculature. They are thought to be involved in regulating neuroprotection, inflammation, and vascular integrity. GLP-1 is detected in the optic nerve and retinal ganglion cells. It seems that these receptors contribute to neuroprotection and that GLP-1 RAs would reduce axonal injury. However, GLP-1 receptors also exist in the ocular arteries and appear to be involved in the regulation of blood flow in the eye.

While the exact mechanism of injury is not known and causality has not yet been scientifically proven, an association appears to exist between these rare but catastrophic cases of NAION and these semaglutide and tirzepatide GLP-1 RA medications. There are many GLP-1 receptors throughout the eye, and these drugs exert action on them. Given their role in neuroprotection and the regulation of blood flow in the eye, it is medically plausible that further study will determine an underlying mechanism of injury that shows that these drugs cause NAION in a small subset of people who take them.