“Eye Stroke” and Weight Loss Injections: What You Need to Know

Recent reports have highlighted a rare but serious potential side effect linked to weight-loss injections, often referred to as an “eye stroke.” While not a formal medical diagnosis, this term describes a condition that can lead to sudden vision loss. Here’s a breakdown of what you need to understand about this emerging health concern.

What is an “Eye Stroke”?

An “eye stroke” isn’t a stroke in the traditional sense – it doesn’t typically cause limb weakness or speech difficulties. Instead, it refers to a condition called non-arteritic anterior ischaemic optic neuropathy (NAION), where reduced blood flow damages the optic nerve, potentially causing sudden, painless vision loss in one or both eyes. The term “stroke” is used because, like a conventional stroke, it’s caused by a loss of blood supply leading to tissue damage.

The Link to Weight-Loss Injections

The connection between NAION and weight-loss treatments, specifically those containing semaglutide, gained attention following a study analyzing over 30 million side effects reported to the US Food and Drug Administration. The study found 31,774 reports involving semaglutide. Wegovy, a higher-dose semaglutide medication, showed a significantly stronger association with NAION than Ozempic, despite having fewer overall reported side effects. The risk of eye stroke with Wegovy was almost five times greater than with Ozempic.

How Semaglutide Might Be Involved

Semaglutide is a synthetic version of GLP-1, a naturally occurring hormone that regulates blood sugar by stimulating insulin production, reducing glucagon release and slowing digestion. While used to treat type 2 diabetes, heart disease, and obesity, the rapid weight loss induced by Wegovy may play a role. The body is a complex system, and significant hormonal alterations can have unexpected effects.

Fluctuations in blood pressure, potentially caused by the higher doses of Wegovy, could also contribute. The retina relies on a delicate network of tiny blood vessels for oxygen, making it vulnerable to disruptions in blood flow.

Who is at Higher Risk?

The study revealed a notable disparity: men taking these weight-loss treatments faced three times the risk of vision loss compared to women. The reasons for this difference are still unclear and require further investigation.

What Do the Manufacturers Say?

Novo Nordisk, the manufacturer of Wegovy, Ozempic, and Rybelsus, states that patient safety is their top priority and they are closely monitoring the safety profiles of their products. They have updated the EU patient leaflets for these medications to include information about NAION, but maintain that the benefit-risk profile of semaglutide remains favorable.

What Should You Do?

While the risk of NAION remains rare, it’s crucial to be aware of the potential side effect. If you are taking semaglutide and experience sudden vision loss, consult your doctor immediately. More research is needed to determine safe dosage levels and identify individuals who may be more susceptible.

NAION causes a sudden, painless loss of vision, typically noticed upon waking. Vision may worsen over a couple of weeks before stabilizing, and recovery is variable, with around 70% of people experiencing no improvement.