The emerging concerns surrounding GLP-1 medications, such as Ozempic, potentially leading to vision impairment are gaining attention. A recent study released this week highlights several individuals who experienced eye issues shortly after beginning treatment with semaglutide and comparable drugs.

Researchers, including eye specialists from the University of Utah Health, have documented a series of cases involving vision complications associated with these obesity and diabetes medications. These drugs have been correlated with three distinct eye disorders, all of which carry the risk of blindness. However, the medical professionals emphasize that these reports do not provide definitive proof that GLP-1 medications are the causative factors, underlining the necessity of further investigation to clarify the situation.

Additional studies have recently indicated a potential relationship between GLP-1 drugs, such as semaglutide (the active component of Ozempic and Wegovy) and tirzepatide (Mounjaro and Zepbound), and an increased likelihood of experiencing specific ocular issues.

For instance, a study released last summer by specialists at a dedicated eye hospital found that individuals prescribed semaglutide were significantly more prone to develop nonarteritic anterior ischemic optic neuropathy (NAION), a rare ailment linked to reduced blood flow to the optic nerve. Additionally, in December, health authorities in Denmark urged the European Union to conduct a formal investigation regarding the potential connection between GLP-1 usage and NAION, following findings from two separate studies involving Danish patients that revealed similar trends.

The latest study, published last month in JAMA Ophthalmology, documents nine specific cases. Among these, seven individuals experienced NAION upon starting a GLP-1 medication; one individual faced papillitis, an inflammatory condition of the optic nerve; while another suffered from paracentral acute middle maculopathy, a type of damage to blood vessels in the macula—the region in the retina that provides detailed vision. In numerous instances, those affected noted that their vision either improved or stabilized upon discontinuation of the medication, although a few continued their treatment without enduring long-term complications.

The authors of the research emphasize that these isolated instances do not serve as conclusive evidence establishing that GLP-1 medications are responsible for these ocular issues. “In this case series study, it was not possible to determine if there is a causal link between these drugs and the ophthalmic complications reported,” they noted. Should a causal connection exist, it may be more complex than it appears at first glance.

Significantly, nearly all individuals involved had a history of type 2 diabetes, a condition characterized by persistently high blood sugar levels. The researchers point out that some instances of papillitis have been associated with rapid reductions in blood sugar levels, and suggest similar mechanisms could be at play for some NAION cases. This indicates that GLP-1 medications may indirectly contribute to these issues by swiftly lowering blood sugar, rather than through any direct toxic effect of the medication itself. Furthermore, other factors may come into play, as some optic nerve cells possess GLP-1 receptors, offering an additional pathway through which these medications could impact eye health.

Regardless, the researchers advocate for additional investigations into this potential association. Although NAION is a rare condition, even a minor increase in risk could have significant implications considering the rising global popularity of these drugs. Gaining a deeper understanding of the mechanisms involved could enhance patient care. If these conditions stem from abrupt decreases in glucose levels, as suggested by the researchers, implementing a more gradual GLP-1 treatment approach in high-risk individuals could help mitigate future occurrences (commonly, GLP-1 therapy is introduced through gradually increasing doses). The doctors also aspire for their findings to raise awareness among their peers.

“Further studies are needed to test our hypothesis. However, this is an important issue for ophthalmologists as we monitor usage of these drugs and how to best communicate with our patients regarding them,” stated Bradley Katz, a neuro-ophthalmologist at the John A. Moran Eye Center at the University of Utah.