Popular medications used for diabetes and weight loss are under the spotlight again. A new medical report describes two patients who developed a rare eye condition after taking the GLP-1 drug dulaglutide, better known by the brand name Trulicity. The condition, called choroidal lymphoid hyperplasia (CLH), caused vision loss in one eye in both cases. However, the good news is that when the patients stopped taking the drug, their eyesight returned to normal.

This report, published as a correspondence in the New England Journal of Medicine, has raised questions among patients who take GLP-1 medications. But experts are quick to point out that this side effect appears to be exceedingly rare. For the millions of people who take these drugs, the benefits likely far outweigh the tiny risk of this condition.

What Exactly Happened in These Two Cases?

Doctors at Memorial Sloan Kettering Cancer Center in New York City treated two patients who developed vision problems after starting dulaglutide. The first patient was a 47-year-old man. He started experiencing blurry vision in one eye about two months after he began taking the medication. The second patient was a 70-year-old woman who noticed vision loss in one eye three months after starting the drug.

Both patients were taking different doses. The man was on 1.5 milligrams of dulaglutide each week. The woman was on a higher dose of 3 milligrams each week. When doctors examined their eyes, they found a creamy-orange colored buildup in the back of the eye, near the macula. The macula is the part of the eye responsible for sharp, central vision.

Further testing revealed more problems. Imaging scans showed that both patients had abnormalities in the choroid and retina. The choroid is a layer of blood vessels and tissue between the white of the eye and the retina. Additionally, full-body PET/CT scans showed that both patients had swollen lymph nodes throughout their bodies. A lymph node biopsy in the man confirmed that he had lymphoid hyperplasia, which is a non-cancerous overgrowth of immune cells.

The man first tried treatment with steroid medications. He took oral steroids and antibiotics for two weeks, but his vision did not improve. He then received a steroid injection around the eye, which helped temporarily. But the condition came back 10 months later. It was only when he stopped taking dulaglutide because of stomach problems that his vision dramatically improved. One month after stopping the drug, his vision returned to 20/20. His eyes remained healthy for 43 months of follow-up. Interestingly, he later took other GLP-1 drugs called semaglutide and tirzepatide without any eye problems.

The woman had a faster recovery. Based on what doctors learned from the first case, they advised her to stop taking dulaglutide right away. Just 10 days later, her vision improved from 20/150 to 20/25. Follow-up scans showed that the swelling in her lymph nodes also went away completely.

What Is Choroidal Lymphoid Hyperplasia (CLH)?

Choroidal lymphoid hyperplasia is a rare condition where non-cancerous lymphocytes — a type of white blood cell — start to multiply in the eye. It belongs to a broader category called ophthalmic lymphoid hyperplasia. This can affect different parts of the eye, including the uveal tract (the middle layer of the eye), the conjunctiva (the clear tissue covering the white part of the eye), the eyelid, or the eye socket.

In some rare cases, this condition can slowly turn into a low-grade lymphoma, which is a type of cancer. But in the two patients described, the condition was benign and reversible. Experts believe that CLH might be triggered by an immune response to something the body sees as a threat. In these cases, the trigger appears to have been the GLP-1 drug.

How Does This Affect People Taking GLP-1 Drugs?

If you are taking a GLP-1 medication like Trulicity, Ozempic, Wegovy, Mounjaro, or Zepbound, you might be worried after reading this news. It is important to keep things in perspective. These drugs are taken by millions of people around the world. The two cases described are the only ones doctors have seen so far linking dulaglutide to this specific eye condition.

Dr. Jasmine H. Francis, the lead author of the report, told MedPage Today that her team has seen no additional patients with this problem. She emphasized that the condition is “exceedingly rare.” She also stressed that if it is recognized early, it can be reversed by stopping the medication.

That said, this is not the first time GLP-1 drugs have been linked to eye problems. There have been multiple reports suggesting a possible connection between these drugs and a condition called nonarteritic anterior ischemic optic neuropathy, or NAION. NAION is a more serious condition that can cause permanent vision loss. The European Medicines Agency has specifically looked at semaglutide (the active ingredient in Ozempic, Wegovy, and Rybelsus) and recommended updating product information to mention this potential risk. However, other studies have found no link between GLP-1 drugs and NAION.

When it comes to diabetic retinopathy — a common eye problem in people with diabetes — the research is mixed. Some studies suggest GLP-1 drugs might help protect against age-related macular degeneration. Another recent study found that better diabetes treatment, including GLP-1 drugs, has reduced the risk of diabetic eye disease getting worse, even though it has not reduced how many people develop it in the first place.

What Experts Say About This Finding

Medical experts who were not involved in the report say that while the cases are interesting, they do not prove that dulaglutide causes CLH. The report is what scientists call a “case series,” which describes what happened to two people. This type of evidence is useful for spotting potential problems, but it cannot prove cause and effect.

The researchers themselves are cautious. They wrote that the timing of the eye problems starting after the drug, and the quick recovery when the drug was stopped, raises “concern for a potential association.” But they also admitted that the mechanism is unclear. They speculated that activating the GLP-1 receptor in the eye’s blood vessels might explain the local eye problem, but it does not explain why the lymph nodes throughout the body were also affected.

Dr. Francis and her team noted that they have “no new thoughts about the etiology or mechanism to explain why the drug would cause this.” This honesty underscores how little is known about this potential side effect.

Practical Takeaways for Readers

If you are taking a GLP-1 medication, here is what you need to know:

• Do not stop your medication without talking to your doctor. These drugs are highly effective for managing blood sugar in type 2 diabetes and for weight loss. Stopping them suddenly can have serious health consequences.
• Know the warning signs. If you experience blurry vision, vision loss in one eye, or any sudden change in your eyesight, contact your doctor right away. This is true whether you take GLP-1 drugs or not.
• Keep up with regular eye exams. People with diabetes should have a dilated eye exam at least once a year. This can catch eye problems early, whether they are related to medication or not.
• Understand the risk is tiny. With millions of people taking these drugs, and only two reported cases of this specific eye condition, your personal risk is extremely low.
• Report any side effects. If you experience anything unusual while taking a GLP-1 drug, tell your doctor. They can report it to the FDA or other health authorities, which helps track rare side effects.

The Bottom Line

The link between dulaglutide and choroidal lymphoid hyperplasia is based on just two patients. The condition was reversible in both cases. While it is important for doctors and patients to be aware of this potential side effect, it should not scare people away from using these life-changing medications. As always, the best approach is to stay informed, communicate with your healthcare provider, and pay attention to any changes in your body — including your eyes.

Source: MedPage Today