Prescription weight loss drugs have grown in popularity since receiving approval from the Food and Drug Administration to help manage blood sugars and weight loss. However, like many drugs, these GLP-1 medications can come with potential side effects, and recent studies show they may cause vision changes.
While using these drugs can speed weight loss, patients should be aware of the potential risks and the health benefits associated with these drugs. When it comes to eye health, preliminary research indicates some concerning side effects such as blurred vision and a condition called anterior ischemic optic neuropathy,where blow flow to the eye is blocked. This class of medications has also been linked to worsening the risk of developing wet macular degeneration.
“While more studies are needed to fully understand the long-term benefits and risks of GLP-1 medications and eye health, current consensus is the overall health benefits for patients using this medication outweighs the risk of potential ocular complications,” says Nazanin Barzideh, MD, Retina Specialist at New York Eye and Ear Infirmary of Mount Sinai. People who use GLP-1 medications to control their diabetes should see their ophthalmologist to monitor their eye health, she says.
Nazanin Barzideh, MD
In this Q&A, Dr. Barzideh, MD, addresses some key questions about GLP-1 medications (which includes drugs such as Ozempic® and Wegovy®) and their potential effects on vision and eye health.
How do these medications work?
These medications promote insulin production and decreases blood sugar levels, which can lead to better diabetes control and decrease the risk of cardiovascular disease while promoting weight loss. They are called GLP-1 medications because they mimic the action of a hormone called GLP-1. They contain the active pharmaceutical ingredient known by its chemical name, semaglutide.
Can GLP-1 weight loss drugs cause vision issues?
One of the side effects that some patients may experience is blurred vision. Changes to blood glucose levels can affect the shape of the eye’s lens that may cause blurred vision. Often older adults are more likely to experience blurred vision when they start taking the medication because the eye’s lens is less flexible as we get older, and it takes the body longer to adjust to changes in blood sugar levels. Therefore, it takes longer to stabilize vision. This is side effect is temporary and usually resolves in three to four months.
Can these drugs cause blindness?
There’s no direct evidence that these medications cause blindness. But some studies suggest a potential link to a condition called non-arteritic anterior ischemic optic neuropathy (NAION), which can lead to vision loss. NAION is a type of “eye stroke” where blood flow to the optic nerve is reduced or blocked, causing sudden, painless vision loss, often in one eye. The risk of occurrence of NAION is low with this class of medication. Patients with smaller optic discs, part of the optic nerve, are at higher risk of developing NAION. The risk for NAION is also higher the first year of use of this class of medication. Regular eye exams are suggested while patients are on this class of medication.
More research is being done to investigate whether GLP-1 medications affect blood flow or oxygen levels in the eye, which could increase a patients’ risk of developing age-related macular degeneration (nAMD) and/or have a negative implication for patients who already have nAMD. Researchers also want to learn more about the long-term ocular effects of prolonged exposure. Whether you take GLP-1 drugs for weight loss or to treat diabetes, it is important to control your blood sugar at a steady pace and consult an ophthalmologist if you experience any changes in your vision.
What are the ocular risks of taking GLP-1 over the long term?
The long-term ocular safety of GLP-1 medications requires further investigation to determine whether prolonged exposure could play a part in increasing risk.
Does prolonged use of GLP-1 medications affect patients who have diabetic retinopathy?
The implications of long-term use of GLP-1 medication and diabetic retinopathy progression requires further study. Diabetic retinopathy involves damage to small blood vessels in the retina. For most patients, the cardiovascular and blood sugar control benefit of these drugs outweigh the small risk of retinopathy progression. In the long term, the diabetic retinopathy will be better controlled with improved diabetic control. This is consistent with current American Academy of Ophthalmology guidelines. Patients should discuss their concerns with their health care providers, who can assess the potential risks and benefits in the context of their individual overall health needs.