Taking semaglutide for weight loss and diabetes, sold under the popular brand names Ozempic and Wegovy, may be linked to an increased risk of developing an eye disease that can lead to vision loss and blindness, according to a study published last week in JAMA Ophthalmology.
Compared with people who were prescribed other types of medications for type 2 diabetes or to lose weight, those taking semaglutide were more likely to develop nonarteritic anterior ischemic optic neuropathy, or NAION, which occurs when the optic nerve does not receive enough blood flow.
What does this mean for people who take (or want to take) semaglutide or another type of weight-loss drug? The study authors cautioned that this was an observational study, which means more research is needed to confirm the extent of the increased risk of eye problems in people taking diabetes or weight-loss drugs (or whether there is a risk at all). Eye health aside, the weight-loss drug craze has spawned a host of different health links — some of them positive — and researchers need more time to iron out those definitively.
The JAMA study also did not study tirzepatide (brand names Mounjaro or Zepbound), which is a drug similar to semaglutide that emerged in the Ozempic and Wegovy wave, but works a little differently.
The study’s lead author, Dr. Joseph Rizzo, who is also director of neuro-ophthalmology at Mass General Brigham’s Mass Eye and Ear, called the study’s findings “significant but tentative” in a Mass General Brigham news release.
“This is information we didn’t 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 significant pre-existing visual loss from other causes,” Rizzo said.
Novo Nordisk, which makes Ozempic and Wegovy, did not immediately respond to a request for comment.
Here’s what we know now.
What is NAION?
NAION is a type of ocular stroke that causes vision loss or blindness due to insufficient blood flow to the optic nerve, which is located 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 middle-aged and older people, and the shape of a person’s optic nerve may even play a role in stroke risk. Other risk factors for NAION include 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 doesn’t move, sensitivity to light, 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 is no proven treatment for NAION at this time, according to Penn and the AAO, but reducing your vascular risk factors (being physically active, lowering blood pressure, aiming for healthy blood sugar levels, etc.) can help prevent it.
If you experience vision loss or severe pain around your eyes for any reason, you should seek medical attention immediately.
Learn more: 10 Simple Ways to Protect Your Eyes Every Day
Does weight loss and treatment for type 2 diabetes benefit or harm eye health?
Beyond NAION, there is an established link between diabetes and eye health. Diabetic retinopathy, a complication of diabetes caused by damaged blood vessels in the back of the eye, is the leading cause of blindness in American adults, according to the American Diabetes Association. So it would be natural to think that treating or managing diabetes could reduce 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 a 2017 study that found that taking semaglutide could put patients with diabetic retinopathy at increased risk of complications once they start taking the drug and their blood sugar and insulin levels begin to stabilize. In 2023, however, research presented at the AAO annual meeting found that this link between diabetic eye problems and rapid correction of blood sugar levels is not as strong as previously thought.
In a press release Monday about the latest study results in JAMA Ophthalmology, the AAO noted that previous studies have linked semaglutide to blurred vision, worsening diabetic retinopathy and macular complications. The eye health organization noted that blurred vision can occur because sudden changes in blood sugar levels can affect the shape of the eye, causing blurry vision. The AAO also noted that these changes are usually temporary and go away after a few months.
For some people taking semaglutide or a drug in a similar but different class called tirzepatide (Mounjaro or Zepbound) for doctor-recommended weight loss, the subsequent risk of developing long-term health problems like diabetes or heart disease (vascular factors like blood pressure also influence eye health) may be reduced in the first place. Although some experts have speculated that drugs like semaglutide might reduce the risk of eye diseases like glaucoma in patients who are at higher risk because of BMI, there is not enough evidence of a strong link between eye health and weight loss at this time, Optometry Advisor reported.
If I take semaglutide, should I be concerned about my eyes?
At this time, the AAO is not recommending that people stop taking semaglutide; it noted that 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 your doctor to find out which medication is best for you and your health, as the risk/benefit profile differs from person to person. If you have a history of eye problems or have other risk factors for NAION, it may be a good idea to consult your doctor to ensure that you continue to benefit from the health management plan you have chosen.
To learn more, discover how you can protect your eyes every day, the best foods to eat for vision health, and why there may be unexpected links between new weight-loss drugs and health effects like fertility and sleep apnea.