Ophthalmic complications in patients on antidiabetic GLP-1 medications are concerning neuro-ophthalmologists

BUFFALO, N.Y. — A small percentage of patients taking the extraordinarily popular GLP-1 medications have experienced vision problems, but a direct causal link with the drugs has not been established. That is the conclusion of a retrospective study published online on Jan. 30 in JAMA Ophthalmology.

The study focused on nine patients who had experienced vision problems while using semaglutide (brand names Wegovy and Ozempic) and tirzepatide (brand names Mounjaro and Zepbound).

The paper is one of several in the past year that have documented vision problems in patients using these drugs. Several patients have presented with a medical condition called nonarteritic anterior ischemic optic neuropathy (NAION), a non-inflammatory disease of small blood vessels in the anterior portion of the optic nerve. The condition occurs when blood supply to the optic nerve is insufficient, damaging the nerve and resulting in sudden partial vision loss that is usually permanent.

The recent JAMA study came about when senior author Bradley J. Katz, MD, of the John A. Moran Eye Center at University of Utah Health, saw a patient who experienced sudden painless vision loss after starting semaglutide. The patient stopped using the drug briefly but then experienced the same thing in the other eye when the internist put the patient back on the drug.

That prompted Katz to post a question on a national neuro-ophthalmology listserv to see if his colleagues were seeing similar things in their patients. Neuro-ophthalmology merges the fields of neurology and ophthalmology, often dealing with complex systemic diseases that manifest in the vision system.

Feedback from neuro-ophthalmologists 

The nine cases described in the paper are the result of feedback Katz received from his colleagues in neuro-ophthalmology.

“We’re trying to elucidate if being on these drugs can increase your risk,” says Norah S. Lincoff, MD, a co-author on the paper and professor of neurology in the Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo. She is the neuro-ophthalmologist at UBMD Neurology.

The paper reports that seven of the nine patients had a NAION-like presentation; one had papillitis, which is inflammation of the optic nerve head; and one had a condition called paracentral acute middle maculopathy, which can cause a blind spot in one’s vision. Some of the patients had atypical symptoms. For example, while NAION nearly always presents only in one eye at a time, some patients presented with it in both eyes at the same time.

The authors point out that other classes of drugs, including those treating erectile dysfunction and an anti-arrythmic drug, have previously been found to cause NAION in some patients; some of those have led to labeling changes on the drugs.

While reports of patients on semaglutide and tirzepatide with vision problems are still rare, there are concerns, the authors say, because demand for the drugs is skyrocketing. A 2024 study reported that 12% of the U.S. population has ever taken one of these drugs and that approximately 6% of the population is currently taking them.

Comorbidities are a factor

The patients, all in their 50s and 60s, were prescribed these drugs in the first place because they have diabetes or obesity, as well as other cardiovascular comorbidities, which can by themselves cause diabetic retinopathy, blurring or other vision issues.

“So are these drugs increasing the risk for an episode of visual loss?” Lincoff asks. She adds that a rapid reduction in blood glucose levels, which is the goal of these drugs, may put these patients at higher risk.

And she notes it is well-known that diabetic patients who aren’t on these drugs may have blurring for an hour or two because fluctuations in blood sugar can affect vision temporarily.

“The message to the patient is that we are still investigating if these drugs put them at higher risk of ischemic optic nerve damage,” says Lincoff. “The message to the primary care provider is, if a patient on one of these medications calls you and says that there is blurring or vision loss, have them see their ophthalmologist as soon as possible. Don’t wait. Maybe it’s a fluctuation in glucose or it could be something more serious.”

She adds that because these drugs provide well-documented benefits, people should not randomly decide to go off them. But if a patient taking these drugs experiences vision loss, they should call their internist about possibly adjusting the dosage or stopping the medication.

“We have other ways to control diabetes and weight loss,” she says. “There are many options for patients.”

She adds that the authors are joining with the American Academy of Ophthalmology in recommending a post-marketing survey to more accurately assess the number of patients receiving these drugs who experience an adverse ocular reaction.