Story Highlight
– Wegovy increases risk of vision loss compared to Ozempic.
– NAION linked to semaglutide injections in new research.
– Risk is five times higher for Wegovy users.
– Ozempic reports outnumber Wegovy, but risk stronger for Wegovy.
– No treatments available for NAION, vision loss often permanent.
Full Story
A recent study has unveiled a potential concerning link between the weight loss drug Wegovy, known for its active ingredient semaglutide, and an increased risk of a serious eye condition that could result in permanent vision loss. This condition, known as nonarteritic ischemic anterior optic neuropathy (NAION), raises alarms for users of this medication, which has gained widespread recognition for its effectiveness in combating obesity and type 2 diabetes.
Semaglutide has been celebrated as a significant advancement in weight management therapies, often leading to substantial weight loss among users. With the recent findings, health authorities in the UK have officially acknowledged the heightened risk associated with the use of semaglutide injections, particularly in the context of Wegovy.
For individuals unfamiliar with NAION, it is often described as an “eye stroke.” This debilitating condition arises when blood flow to the optic nerve is disrupted, leading to oxygen deprivation and, consequently, damage to the nerve itself. The implications of such a condition are severe, as it can lead to abrupt and permanent vision loss.
British researchers have identified that individuals using Wegovy are five times more likely to experience NAION compared to those using Ozempic, another medication containing semaglutide. Furthermore, their analysis indicates that the risk of ischaemic optic neuropathy was three times more pronounced among men than women, highlighting a potentially alarming disparity.
The study, published in the British Journal of Ophthalmology, articulates a “dose-dependent safety concern” regarding semaglutide. The researchers emphasize that the risk of developing ischaemic optic neuropathy is linked not only to the dosage but also to the formulation of the drug. They reported that while Ozempic had earlier approval and saw a significant volume of adverse event reports, Wegovy was associated with a stronger signal linking it to this serious eye condition.
To support their findings, researchers from the University of Ottawa conducted a thorough examination of adverse event reports compiled by the US Food and Drug Administration (FDA) from December 2017 to December 2024. Among over 30 million reported alerts, a total of 31,774 were related to semaglutide usage. Following the launch of Wegovy in 2021, 3,070 reports were linked to it, while Ozempic, which has been available since 2017, accounted for 20,608 alerts. Notably, the study indicates that Wegovy poses a greater risk for developing ischaemic optic neuropathy than both Ozempic and generic semaglutide products.
Interestingly, the research did not find an association between ischaemic optic neuropathy and Rybelsus, the oral form of semaglutide prescribed for type 2 diabetes. Experts speculate that this discrepancy may be due to the different absorption processes between injectables and oral medications, suggesting that the quicker action of injections may influence the likelihood of such adverse effects.
In response to these alarming findings, a spokesperson from Novo Nordisk, the manufacturer of both Wegovy and Ozempic, stated, “Patient safety is our top priority, and we take any reports about adverse events from the use of our medicines very seriously.” Furthermore, they confirmed that patient information leaflets for their products have been updated to include warnings about NAION. Nevertheless, the company maintains that the available data does not sufficiently imply a causal relationship between semaglutide and NAION, asserting that the overall benefit-risk profile for semaglutide remains favourable.
Previous studies have drawn connections between semaglutide and NAION, with many acknowledging a low risk associated with its use. Notably, a US study from last year documented nine instances of blindness related to the use of semaglutide or tirzepatide, another weight-loss drug. Researchers speculated on the possibility that rapid reductions in blood sugar levels, a side effect of these medications, could lead to vascular issues within the eyes.
The renowned singer Robbie Williams expressed his own concerns regarding these injections in an interview, revealing that he discontinued using Mounjaro due to fears of losing his vision. He remarked, “I don’t believe it’s age – I believe it’s the jabs,” indicating that his experiences with the medications were raising significant worries about his eyesight.
NAION affects approximately one in every 10,000 individuals, and sadly, there are currently no effective treatments available. Unlike other strokes characterized by other symptoms, those afflicted with NAION typically do not experience pain, identifying the loss of vision in one eye, most commonly noticed upon waking.
NAION stems from inadequate blood flow to the optic nerve, which may be exacerbated by factors such as diabetes, hypertension, and sleep apnoea. Smoking is also identified as a risk factor. People dealing with NAION often possess anatomical variations in the optic nerve that can result in constricted circulation, potentially exacerbating the condition.
While once diagnosed with NAION, it is rare for it to recur in the same eye, approximately 30% of patients may face a risk of it affecting the other eye over their lifetime. As a preventive measure, medical professionals might suggest lifestyle modifications such as regular exercise, a balanced diet, and addressing underlying health conditions, including diabetes and hypertension.
The findings included in this recent study serve as a critical reminder of the complexities and potential risks associated with weight-loss therapies. As the conversation surrounding effective obesity management continues, it is imperative for patients to remain informed about both the benefits and dangers associated with these popular medications.
Our Thoughts
The emergence of research linking Wegovy to an increased risk of nonarteritic ischemic anterior optic neuropathy (NAION) highlights significant safety concerns that could have been mitigated. The primary lesson is the importance of rigorous pharmacovigilance, particularly in post-marketing surveillance of new medications. Companies should ensure that adverse event reporting systems are robust, transparent, and responsive to emerging safety signals.
Regulations under the UK Medicines and Healthcare products Regulatory Agency (MHRA) require all pharmaceutical companies to monitor the safety of their products continuously. Prompt updates to patient information leaflets regarding potential risks, as done by Novo Nordisk, are crucial, but must be coupled with immediate clinical studies to further understand these risks.
Furthermore, healthcare professionals should receive clear guidance on the risk profiles of different formulations, emphasizing the dose-dependence of adverse effects. Creating stricter dosing guidelines and a thorough informed consent process about potential side effects could also help mitigate such risks in new pharmacological treatments.
To avoid similar incidents, there should be ongoing education for users regarding side effects and close monitoring for individuals starting these medications, particularly when transitioning to new formulations like Wegovy.
