Why You Can Trust CNET Is There a Connection Between Weight-Loss Drugs and Vision Loss?
A study links semaglutide -- the ingredient in Ozempic -- with a condition that causes vision loss. Here's what we know about semaglutide and eye health.
- Added coconut oil to cheap coffee before keto made it cool.
Taking semaglutide for weight loss and diabetes, which sells under popular brand names Ozempic and Wegovy, may be linked to an increased risk of developing an eye condition that can lead to vision loss and blindness, according to a study published last week in JAMA Ophthalmology.
Compared to people who were prescribed other types of medication for Type 2 diabetes or weight loss, those who took semaglutide were more likely to develop nonarteritic anterior ischemic optic neuropathy, or NAION, which occurs when the optic nerve doesn't get enough blood flow.
What does this mean for people who are taking (or wish to take) semaglutide or another type of weight-loss drug? The study's authors cautioned that it was observational one, meaning more research is needed to confirm the extent of the increased risk for eye problems in those taking diabetes or weight-loss drugs (or whether there is a risk at all). Outside of eye health, the weight-loss medication craze has ushered in a slew of different health connections, including positive ones.
The JAMA study also didn't research the effects of other GLP-1 medications, including tirzepatide (brand names Mounjaro or Zepbound), which is a similar medication to semaglutide that kicked off during the Ozempic and Wegovy wave, but it works a little differently.
Lead author of the study Dr. Joseph Rizzo, who's also director of the Neuro-Ophthalmology Service at Mass General Brigham's Mass Eye and Ear, called the results of the study "significant but tentative" in a Mass General Brigham press release.
"This is information we did not have before and it should be included in discussions between patients and their doctors, especially if patients have other known optic nerve problems like glaucoma or if there is preexisting significant visual loss from other causes," Rizzo said.
"Patient safety is a top priority for Novo Nordisk, and we take all reports about adverse events from use of our medicines very seriously," Novo Nordisk, which makes Ozempic and Wegovy, said in a statement. The company reiterated the limitations of the study, and added it has a trial underway to assess the long-term effects of semaglutide on diabetic retinopathy, which is a common eye complication developed by people with diabetes. Past research has found semaglutide may worsen diabetic retinopathy in people who have it, at least early on in their treatment.
Here's what we know now.
What is NAION?
NAION is a type of eye stroke that causes vision loss or blindness through insufficient blood flow to the optic nerve, which sits near the back of the eye and transfers visual information to the brain.
According to Penn Medicine, the exact cause of NAION isn't fully understood, but it's more common in people who are middle-aged or older, and the shape of someone's optic nerve may even play a role in their risk of eye stroke. Other risk factors for NAION include having high blood pressure, diabetes and obstructive sleep apnea.
Symptoms include vision loss in the affected eye, especially upon waking in the morning, usually without pain. Other symptoms include blurred vision, color distortion, a gray or dark spot in your field of vision that don't move, light sensitivity and loss of peripheral vision. Vision loss may increase or change over a few weeks but should stop progressing after two months, according to the American Academy of Ophthalmology, an association of eye physicians and surgeons. There's no proven treatment for NAION at this time, according to Penn and the AAO, but decreasing your vascular risk factors -- getting physical activity, decreasing blood pressure, aiming for healthy blood sugar and more -- may help prevent it.
If you experience vision loss or severe pain around your eyes for whatever reason, you should get medical help immediately.
Read more: 10 Easy Ways to Protect Your Eyes on a Daily Basis
Do weight loss and treating Type 2 diabetes help eye health or hurt it?
Beyond NAION, there is an established connection between diabetes and eye health. Diabetic retinopathy, a diabetes complication caused by damaged blood vessels in the back of the eye, is the No. 1 cause of blindness in American adults, according to the American Diabetes Association. It would be natural to think, then, that treating or managing diabetes may decrease the risk of diabetic retinopathy, a common cause of vision loss.
The relationship is complicated, though. Some research has found a potentially negative link between eye health and semaglutide, including one study from 2017, which found that taking semaglutide may put patients who have diabetic retinopathy at an increased risk of complications when they first start the drug and their blood sugar and insulin levels start leveling out. In 2023, however, research presented at the AAO's annual meeting found that this link between diabetic eye problems and rapid correction of blood sugar levels may not be as significant as what was thought. Novo Nordisk is conducting a study on the long-term effects of semaglutide's on diabetic retinopathy, which is expected to be completed in 2027.
In a news release published Monday on the results of the latest JAMA Ophthalmology study, the AAO noted that previous studies have linked semaglutide to blurred vision, worsening of diabetic retinopathy and macular complications. The eye health organization noted that the blurred vision can happen because sudden changes in blood sugar level can affect the shape of the eye, which causes blurry vision. The AAO also noted these changes are typically temporary and go away after a few months.
For some people taking semaglutide or a similar but different class of drugs called tirzepatide (Mounjaro or Zepbound) for medically recommended weight loss, their subsequent risk of developing long-term health conditions like diabetes or heart disease (vascular factors like blood pressure also influence eye health) may be lowered in the first place. While some experts have hypothesized that drugs like semaglutide may reduce the risk of eye diseases like glaucoma in patients who are at a higher risk because of BMI, there's not enough evidence for a strong link between eye health and weight loss right now, Optometry Advisor reported.
If I'm taking taking semaglutide, should I be worried about my eyes?
As of now the AAO, isn't recommending people stop taking semaglutide; it noted semaglutide was "rigorously studied" and approved for medical use in 2017. The AAO also noted that people in the study developed NAION after their first prescription of semaglutide.
You should always consult with your doctor about which medication is right for you and your health, as the "risks vs. benefits" profile will differ for everyone. If you have a history of eye conditions or you have other risk factors of NAION, it could be a good idea to check in with your provider to make sure you continue to benefit from your chosen health management plan.
For more, read about how you can protect your eyes each day, the best foods to eat for vision health and why unexpected links between new weight-loss drugs and health effects like fertility and sleep apnea may exist.