Q&A: Andrew J. Barkmeier, MD, on the risk of sight-threatening diabetic retinopathy with GLP-1 RA use

Andrew J. Barkmeier, MD, at the 2025 ASRS meeting in Long Beach, California

Andrew J. Markmeier, MD, is an associate professor of ophthalmology, vitreoretinal surgery at Mayo Clinic in Rochester, Minnesota. At the 2025 ASRS meeting, held in Long Beach, California, Barkmeier presented research on GLP-1 medications and diabetic retinopathy risk.

While the SUSTAIN-6 trial showed increased diabetic retinopathy complications with semaglutide, his real-world study of various GLP-1 medications found no differences in diabetic macular edema or proliferative diabetic retinopathy treatment risks between medications. The findings were reassuring, particularly for semaglutide users, and didn't replicate the SUSTAIN-6 results, allowing patients and prescribers to choose medications without diabetic retinopathy concerns.

Note: The following conversation has been lightly edited for clarity.

Modern Retina: At this meeting, you are presenting data on GLP-1 medications. What questions did this research try to answer?

Andrew J. Barkmeier, MD: As we all know these GLP-1 medications are incredibly impactful and powerful medications that more and more patients with type 2 diabetes are using, and we've got a wealth of evidence showing that they have cardiovascular benefits and benefits to kidneys, and as a result these, the uptake of these is rapidly rising. So although many of the cardiovascular outcome trials, including the SUSTAIN-6 trial looking at semaglutide found that they had these significant cardiovascular benefits. The semaglutide trial also showed that there was an increased risk of diabetic retinopathy complications. This was found in the context of rapid lowering of hemoglobin A1c and weight loss. So it's unclear whether this was a medication specific effect or just related to the significant systemic improvements, as we've seen in some prior studies such as the DCCT. So although there are many medications available and they have different systemic effects, we didn't know if this was something that we would see in the real-world population, because the cardiovascular outcome trials looked at a specific subset of patients over a short amount of time with high cardiovascular risk.

MR: What did your study find?

Barkmeier: So our study looks at a more generalizable population of people who received different GLP-1 medications in routine clinical practice. So we looked to see if there was any difference in the risk of diabetic retinopathy outcomes such as treatment for diabetic macula edema or proliferative diabetic retinopathy. So the good news in this study, we found no differences between any of the GLP-1 medications in the risk of treatment for diabetic macula edema or proliferative diabetic retinopathy, which is very reassuring, particularly because semaglutide is one of the most commonly prescribed medications, and we did not replicate the results from the SUSTAIN-6 trial that showed an increased risk of diabetic retinopathy complications relative to any of the other medications. So from our perspective, this offers some reassurance to patients receiving these medications and people prescribing these medications, that they can choose the best medication, regardless of potential or theoretic risk of increased diabetic retinopathy complications.