Concerns Arise Over Vision Loss Linked to GLP-1 Drugs

Despite the growing popularity of GLP-1 medications like Wegovy and Ozempic, recent studies are uncovering some unsettling side effects, notably related to vision loss. These drugs are designed to imitate the glucagon-like peptide-1 hormone, which helps manage appetite, digestion, and blood sugar levels. They’ve become widely prescribed for weight loss and diabetes management.

However, there’s been an increase in reports of vision-related issues associated with these medications, particularly with their active ingredient, semaglutide. This uptick has prompted health regulators in the UK and Europe to reassess the potential risks based on new findings.

A recent study involving researchers from various Canadian universities analyzed adverse event reports collected by the US Food and Drug Administration (FDA) over seven years, from 2017 to 2024, specifically searching for cases of ischemic optic neuropathy (ION).

ION is a rare condition that can lead to sudden and total vision loss due to inadequate blood flow to the optic nerve, and in some instances, the damage can be irreversible.

The researchers aimed to determine how frequently ION occurred in individuals using various formulations of semaglutide: Wegovy for weight loss, Ozempic for type 2 diabetes, and Rybelsus also for diabetes management.

“These findings build on our previous global analysis, and while earlier research highlighted an agent-specific correlation, this study offers the first evidence that the risk of ION is dependent on the formulation and dosage, with Wegovy showing the strongest association,” the authors stated in their publication.

The analysis revealed that the likelihood of ION complaints associated with Wegovy was nearly five times greater than with Ozempic, although no significant connection was established between Rybelsus and ION.

While the numbers are notable, it’s crucial to consider the bigger picture. The FDA database the team analyzed consists of over 30 million reported adverse events, which included 28 cases linking Wegovy to ION and 47 cases for Ozempic.

It’s worth noting that Ozempic has been on the market longer than Wegovy. Yet, the study indicated that Wegovy had the highest signal for ION risk, remaining significant even after adjusting for demographic details like age and gender. Specifically, the odds of ION among Wegovy users were approximately 4.74 times greater compared to Ozempic, based on the recorded cases.

Interestingly, the study also found a gender disparity: men using semaglutide were about three times more likely to experience ION compared to women.

These results, while derived from a specific FDA database and not representative of the global population prescribed semaglutide, still raise alarm bells among experts. They advocate for further investigation into these findings.

“These findings highlight a potential safety concern that is dose-dependent and requires immediate evaluation to inform prescribing practices and regulatory policies,” the researchers emphasized.

Although the study didn’t delve into the reasons behind the association between GLP-1 drugs and vision loss, the researchers hinted at a few theories. For instance, it’s possible that higher doses of Wegovy could lower blood pressure, which might reduce blood flow to the eyes.

This is a hypothesis that could benefit from more research. Meanwhile, as scientists continue to explore the complex impacts of GLP-1 medications, they’ve linked these drugs to various biological effects, ranging from reduced cancer risk to potential increases in depression.

In commentary related to the study, researchers from the University of Southampton, who were not directly involved, emphasized the need for a careful balance between addressing obesity issues and ensuring that treatments remain safe.

They concluded that “more nuanced studies of this nature are necessary for a deeper understanding of how anti-obesity medications affect eye health, particularly given their rising usage.”

This research has been published in the British Journal of Ophthalmology.