Are Ozempic and Wegovy Linked to Blindness?

A new study suggests that people taking semaglutide (brand names Ozempic, Wegovy, and Rybelsus), the common diabetes and weight management drug, may be at a higher risk of developing a rare form of blindness called non-arteritic anterior ischemic optic neuropathy (NAION). This condition, which can cause sudden and irreversible vision loss, has been reported in patients taking semaglutide, prompting further investigation into a possible association and the impact on eye health. Continue reading to learn the risks and ways to protect your eye health while taking semaglutide. 

What Is Non-arteritic Anterior Ischemic Optic Neuropathy (NAION)?

NAION is a type of eye stroke that results in decreased blood flow to the optic nerve and sudden, painless loss of vision in one eye. For those who develop the condition in one eye, the estimated risk of it occurring in the other eye is about 15-30%, depending on underlying risk factors.

Notably, nonarteritic anterior ischemic optic neuropathy (NAION) is the second leading cause of optic nerve blindness after glaucoma. 

NAION is relatively rare in the general population. Researchers at Massachusetts Eye and Ear noted an increase in NAION cases among patients taking semaglutide medications.

Given that prescriptions for these popular weight loss drugs (Ozempic, Wegovy) have soared in recent years, it prompted an examination of previous medical records going back six years. 

The researchers found that among people with diabetes, patients prescribed semaglutide are 4 times more likely to develop NAION. Those who are overweight or obese are 7 times more likely to develop this serious eye complication. The risk is highest in the first year of semaglutide treatment. It is important to remember that these results are from one study and that more studies are needed to establish a causal relationship. 

Unfortunately, there are no effective treatments for NAION. Eyeglasses cannot correct the vision loss which occurs due to an injured optic nerve. 

Risk Factors for NAION

The exact cause of NAION is not known, but risk factors include diabetes, high blood pressure, sleep apnea, and smoking. NAION is also more common in individuals over 50 and those with an anatomical variation of the optic nerve where it is tight and crowded, which can restrict blood flow. 

Some studies suggest that taking blood pressure medications at night may increase NAION risk, though this remains unclear. The link between erectile dysfunction medications and NAION is still being studied.  Read about 10 medications that may harm your eyes.

Warning Signs of Vision Loss

Vision loss from NAION occurs suddenly and painlessly. It is typically a blurring, darkening, or dimming of vision across part of the visual field, often the lower half. Most patients notice vision loss after waking up from sleep.

What Is Semaglutide Prescribed For?

Semaglutide belongs to a group of drugs called glucagon-like peptide-1 (GLP-1) receptor agonists. It is FDA-approved under three separate brand names with different indications:

• Rybelsus is an oral diabetes medication that is used to improve glycemic control in people with type 2 diabetes mellitus. Compare Rybelsus and Ozempic.

• Ozempic is an injectable form of the drug that is used to treat diabetes and lower the risk of major cardiovascular events in people with diabetes and heart disease. 

• Wegovy is a semaglutide injection for chronic weight management, prescribed to people dealing with overweight and obesity.

Compare Semaglutide tablets vs injections for weight loss.

Note: Semaglutide works as an adjunct to a reduced-calorie diet and increased physical activity. 

How Does Semaglutide Work?

Semaglutide is structurally similar to a hormone in the human body called glucagon-like peptide (GLP). It attaches to GLP-1 receptors in the gastrointestinal tract, pancreas, and brain and mimics the action of this hormone. Natural GLP stimulates insulin secretion in response to increased glucose levels after meals. It also slows gastric emptying and decreases appetite. By mimicking these effects of GLP, semaglutide helps to regulate blood glucose levels and promote weight loss.

Read: “How Does Wegovy Work For Weight Loss?”

Ozempic and Blindness: Expert Analysis

Experts say that the study, published in JAMA Ophthalmology, was retrospective and based on medical records, meaning it cannot establish causation, only a potential association. The study population recruited patients from a neuro-ophthalmology specialized medical center, which may overestimate the incidence of NAION compared to the general population. However, the findings do raise concerns about a potential risk of blindness from semaglutide (Ozempic or Wegovy). Future studies and research are needed to understand these risks better.

Novo Nordisk has stated that patient safety is a top priority and that no cases of NAION were reported in clinical trials of semaglutide. 

“The use of these drugs has exploded throughout industrialized countries, and they have provided very significant benefits in many ways, but future discussions between a patient and their physician should include NAION as a potential risk,” lead researcher Dr. Joseph Rizzo, director of Neuro-Ophthalmology at Mass Eye and Ear and a professor at Harvard Medical School, said in a news release.

Dr. Andrew Lee, a neuro-ophthalmologist at Houston Methodist Hospital and clinical spokesperson for the American Academy of Ophthalmology, says, “While there is a biologically plausible mechanism for a potential interaction, the association is not causation and diabetes mellitus is a known risk factor for NAION.” 

“In the ever-changing landscape of systemic therapies, being vigilant for potential new disease associations is a duty we all share on behalf of patients,” says Susan Mollan, an ophthalmologist at the University Hospitals Birmingham in the UK. 

In short, expert opinion at the present time is that we cannot say there is a direct causal relationship between semaglutide use and blindness related to NAION. More research is needed to understand the link. The potential risk of NAION should not deter people from taking semaglutide for obesity or diabetes management. The large number of people taking semaglutide raises confidence that the absolute risk of NAION is rare.

Analyzing The Link Between Semaglutide and NAION

The effects of semaglutide on the eyes are not fully known. Given that we don’t know the exact cause of NAION, the link between semaglutide use and the risk of NAION is unclear. 

Research has shown, however, that changes in blood sugar levels affect the shape of the lens in the eye and, consequently, vision. Semaglutide, which promotes the release of more insulin and a reduction in blood sugar, is known to cause temporary changes in vision, including blurry vision and new or worsening diabetic retinopathy (damage to blood vessels in the retina, the light-sensitive layer at the back of the eye). Scientists believe that the rapid improvement in blood sugar levels achieved on semaglutide leads to these eye changes. 

In the meantime, while researchers continue to study the effects of semaglutide on vision and eye health, labels for both Ozempic and Wegovy include vision changes as potential side effects. 

Read next: Is Semaglutide Safe?

Addressing Concerns About Vision Changes

Can Ozempic Affect Your Eyesight?

Yes, Ozempic (semaglutide) can affect your eyesight. Studies have shown that this diabetes medication can cause vision changes, including blurred vision, new or worsening diabetic retinopathy, and macular changes. However, having diabetes can also cause conditions such as diabetic retinopathy and NAION.

Experts say that changes in eyesight on Ozempic and other similar drugs occur due to changes in sugar levels, which affect the shape of the lens in the eye, causing blurry vision. Temporary vision changes, such as blurriness, may occur when starting semaglutide and typically resolve within a few months after the body adjusts to the medicine. However, worsening diabetic retinopathy and NAION can cause permanent vision impairment.

Can Ozempic and Wegovy Cause Blindness?

Ozempic and Wegovy can increase the risk of developing a rare eye condition that can lead to blindness. This condition is called non-arteritic anterior ischemic optic neuropathy (NAION). However, more research is needed, and a direct causal relationship between these weight loss drugs and blindness has not been established. 

Notably, people who have diabetes are at an increased risk of NAION regardless of whether they take semaglutide or not. In short, while Ozempic blindness is a potential risk, it is not a known side effect.

Can Weight Loss Cause Vision Changes?

According to the American Academy of Ophthalmology, a large amount of weight loss can cause vision changes, especially if there are fluctuations in blood sugar levels. Weight loss injections, such as Ozempic and Wegovy, cause rapid weight loss and metabolic changes. This can potentially cause or worsen diabetic retinopathy in people with diabetes due to a rapid improvement in blood glucose control. 

In addition, the sudden reduction in weight by these weight loss drugs can also lead to nutritional deficiencies, such as vitamin A and vitamin B12, which are vital for eye health. 

Moreover, there are concerns that the changes in the metabolic state due to rapid weight loss may affect the regulation of intraocular pressure and increase the risk of glaucoma in at-risk individuals.

Does Zepbound Cause Blindness?

The active ingredient in Zepbound for weight loss is tirzepatide, which is also sold under the brand name Mounjaro to treat diabetes. Tirzepatide belongs to a group of drugs called glucose-dependent insulinotropic polypeptide (GIP) receptor and glucagon-like peptide-1 (GLP-1) receptor agonists. 

Currently, there is no research linking Zepbound (tirzepatide), which contains a GLP-1 agonist, to NAION or an increased risk of blindness. New research has found that semaglutide users may be at an increased risk of NAION, an eye condition that leads to irreversible vision loss. Because of overlapping mechanisms between Zepbound and Ozempic, it is recommended to monitor vision changes when starting Zepbound. 

Recommendations For Those Taking Semaglutide

Patients who are on semaglutide or considering treatment with weight loss medications should discuss the risks and benefits with their doctor. This is especially important for those who have known eye problems, such as existing vision loss or glaucoma. Patients with a history of diabetes, hypertension, or previous NAION should consider a baseline eye exam before starting semaglutide. Given that NAION from semaglutide is something we are still learning about, it’s important to make an informed decision based on your risk profile.

It is also important to consult with an ophthalmologist (eye doctor) immediately if you develop any vision changes. 

Find out who should not take Wegovy.

When to Seek Medical Care

Sudden vision loss should always be evaluated in an emergency room. It can be a symptom of life-threatening conditions such as stroke and rare eye diseases such as a detached retina that can be reversed with prompt treatment. Only a trained healthcare professional can tell whether the vision loss is an emergency.

Tips For Maintaining Eye Health

• Regular eye exams: Schedule routine eye exams with an ophthalmologist, even if you don't have any noticeable vision problems. This can help with early detection of eye problems and timely treatment. 

• Family history: Understand your family's eye health history, as certain eye conditions are hereditary. 

• Healthy diet: Eat foods rich in vitamins A, C, E, and omega-3 fatty acids, which support eye health and can be found in leafy greens, fish, nuts, and fruits. 

• Sunglasses: Always wear sunglasses that block UVA and UVB rays when outdoors. 

• Digital eye strain prevention: Follow the "20-20-20 rule": Every 20 minutes, look at an object 20 feet away for 20 seconds. Here’s how to relieve eye strain.

• Protective eyewear: Wear safety glasses or goggles when participating in activities that can put you at risk of eye injuries. 

Learn more about maintaining healthy eyes.

Stay Updated On Medical Advisories and Findings

GLP-1 drugs such as Ozempic and Wegovy are relatively new medications (brought to the market in 2017 and 2021, respectively). Healthcare professionals do not have decades of clinical experience with them, and researchers are still studying the long-term effects of these drugs, including potential visual loss (Ozempic eye blindness). 

For this reason, if you are on semaglutide or considering taking it for the management of diabetes or obesity, it is important to stay up-to-date on any new findings or medical advisories and discuss any concerns with your prescribing physician. Also, be sure to seek immediate medical attention if you develop sudden visual loss or sudden blindness in one eye.

Eye Health Developments

Ongoing Studies and Future Research Directions

The manufacturer of semaglutide, Novo Nordisk, has sponsored a trial (expected to be completed in 2027) which is exploring the link between the drug and diabetic retinopathy. 

Other ongoing clinical trials on semaglutide and eye health include:

• A study that is looking at the long-term effects of semaglutide (active medicine) on diabetic eye disease compared to placebo (dummy medicine) in people with type 2 diabetes. 

• A clinical trial that is investigating whether oral semaglutide can be used to treat open-angle glaucoma by improving inner retinal function.

FDA Warnings

The U.S. Food and Drug Administration (FDA) warns that taking unapproved versions of GLP-1 drugs, including semaglutide (Ozempic, Wegovy), tirzepatide (Mounjaro, Zepbound), and other medications for weight loss can be dangerous. These unapproved versions are not reviewed by the FDA for quality, safety, or effectiveness. Compare Mounjaro vs Ozempic for weight loss.

Always obtain a prescription for weight loss drugs only from a qualified health care professional and fill the prescription at a state-licensed pharmacy. Visit the FDA’s BeSafeRx website to learn how to safely purchase prescription medicines online