Unpacking the Ocular Impact of GLP-1s with Timothy McCulley, MD

As glucagon-like peptide 1 receptor agonists (GLP-1 RAs) gain widespread use for diabetes and obesity, their ocular implications are becoming increasingly relevant for ophthalmologists. In a conversation with HCPLive, Timothy McCulley, MD, a professor and chair of the Ruiz Department of Ophthalmology and Visual Science at McGovern Medical School at UTHealth Houston, outlined three key concerns related to these medications.

McCulley presented a talk entitled "Glucagon-like Peptide-1 (GLP-1) Receptor Agonists Update for the Ophthalmologist” at the Texas Ophthalmological Association (TOA) Annual Meeting in Houston, Texas.

As GLP-1 RAs delay gastric emptying, McCulley highlighted the need for preoperative precautions to prevent surgery cancellations due to anesthesia risks. Although data remains inconclusive, reports suggest a potential link between GLP-1 RAs and optic nerve ischemia, prompting caution for patients with a history of ischemic optic neuropathy. Finally, a temporary worsening of diabetic retinopathy has been observed upon initiating GLP-1s, though the effect is generally mild and does not warrant avoiding the drug in affected patients.

McCulley emphasized the importance of patient counseling regarding these risks, particularly for those with optic nerve ischemia, both for their protection and to mitigate potential medicolegal concerns. Looking ahead to 2025, McCulley identified artificial intelligence as a dominant theme in ophthalmology, with its role in diagnostics and treatment still unfolding.

This transcript has been edited for clarity.

HCPLive: With the expanding use of GLP-1 RAs for diabetes and obesity, what are some of the more significant ocular implications that more ophthalmologists should be aware of? What conditions should they be closely monitoring?

There are three main ones. One, it delays gastric emptying, so when we do surgery, anesthesiologists want patients to have stopped the GLP-1 inhibitors prior to the day of surgery. And if you don't know that and don't warn your patient, your surgeries get canceled.

Number two, there have been reports of optic nerve ischemia occurring in patients with GLP-1s. I don't know that there's enough data to say definitively that the association is real and not coincidental, but regardless, if you have a patient with an ischemic optic neuropathy in one eye, it's probably best to play it safe and tell them to stop their GLP-1 inhibitor.

In case there is an association, it can protect the other eye, and if nothing else, from a medical legal standpoint, you probably ought to tell them because if the other eye gets involved, and you didn't tell them that, it could be the source of a lawsuit.

And lastly, there is probably a mild, temporary worsening of diabetic retinopathy when patients start the GLP-1 inhibitors. And it is thought to be mild and not to the degree that you should avoid the drug in patients with diabetic retinopathy. And that pretty much sums it up.

HCPLive: When discussing GLP-1 use and diabetic retinopathy risk, is it a patient-provider conversation, or does it involve their endocrinologist or primary care specialist?

It might be something for the folks that are prescribing the GPL-1 inhibitors to warn patients about and suggest that they go see their ophthalmologist, but I doubt they're going to get on the phone with us. It's not, how do I put this, that big of a deal?”

HCPLive: What unanswered questions remain for an ophthalmologist? As GLP-1 use continues to grow, what should they keep an eye out for?

Be aware of when you have patients with ischemic optic neuropathy, about the potential association, and be sure to counsel your patients accordingly, for their sake and your sake.

HCPLive: We're about a quarter of the way through 2025. What are some of the main storylines in ophthalmology that are unfolding?

In all of medicine, it is going to be artificial intelligence. That's going to be number one, seeing how that plays out. I don't know if excitement is the right word, but a whole lot of attention is on it. It's going to fall flat, or it's going to take over. But artificial intelligence is probably number one. The other thing that, not just in ophthalmology, but we have a lot of targeted therapy these days. We have these monoclonal antibodies that are specific for treating malignancy and inflammation, but targeted immunotherapy is revolutionizing how we treat a number of diseases.

McCulley reports no relevant disclosures.

References

McCulley TJ. Glucagon-like Peptide-1 (GLP-1) Receptor Agonists Update for the Ophthalmologist. Presented at Texas Ophthalmological Association (TOA) Annual Meeting. Houston, Texas. March 21-22, 2025.