Ehsan Rahimy, MD, and Joseph M. Coney, MD, review the available treatment options for diabetic macular edema.
Nancy Holekamp, MD: We’re going to spend the next 45 minutes discussing treatment options and talking about what retina specialists do for patients with diabetic macular edema [DME]. I think we all like to address the patient and discuss the holistic general things that can improve their overall health, not only their eye health. Ehsan, what modifications to diet or lifestyle do you recommend for patients before you begin your ophthalmic interventions?
Ehsan Rahimy, MD: I like the A, B, C, D, E that Joe mentioned: A1C [glycated hemoglobin], blood pressure, cholesterol, diet, and exercise all make a big difference. Modification is to stop smoking, but many patients have smoked for years, and our success rates are low, so I’m always hammering away with patients about that. If we gathered the different medical specialists and looked at our accumulative success rate to get patients to cut back or quit smoking, then we’d be at the top of the list because there patients—when they know their vision is on the line and they go blind—who cut out everything. They make radical lifestyle changes, which is 1 of the beneficial things about our specialty: seeing how we can help or shepherd the transition that some of our patients undergo when they realize what’s at stake.
I’ve seen amazing turnarounds. It’s not everybody of course. And it’s not just about A1C anymore—we’re seeing more now that our patients are on continuous glucose monitors [CGMs]. There’s the Dexcom G6—the G7 is coming, the Abbott FreeStyle Libre. I’ve been imploring the research side that we should look into this. I’ve seen retinopathy burn out and become stable when patients go on CGMs. It’s not that the CGM is doing something directly to their retinopathy. It’s impacting and influencing behaviors. It induces behavior modification as patients receive continuous feedback.
When you talk to endocrinology colleagues, it’s not about A1C anymore. They talk about TIR, time in range, and when these CGMs are continuously monitoring you; ideally you want to be above 70% time in range. The rate limiting sets their access and affordability, we know there’s more widespread coverage for glucose monitors, but it doesn’t apply to all our patients. In a perfect world, all our patients can get on them because there are remarkable transformations when patients go on it. The idea is the same for the rest of the body as it is with the eye. We’re eliminating large fluctuations and going toward a steady state.
I used to say 1 thing, but it’s changed now that we’ve seen a lot of the real-world outcomes. When we see these large-scale studies published—showing how unfortunate some of the real-world outcomes are for our patients, with various retinal diseases, not just diabetes—my goal is preservation of vision. Some patients will still lose vision in the long run, which could be because of under treatment. Many real-world studies are coming out and showing us that patients don’t likely adhere to as strict a regimen as we see on the clinical trial side. Patients are getting substantially less numbers of intravitreal injections, or some of our patients are much sicker overall in general—they wouldn’t qualify to be in some of these clinical trials. To get some of these great visual acuities that we’re seeing, not everybody is going to gain vision. My goal is to preserve vision for my patients for as long as possible.
Nancy Holekamp, MD: Ehsan, you make me hopeful that with CGMs and this paradigm shift toward time and range, that people will turn their lives around. If I’m seeing a patient with DME who’s still getting injections, they’ll say, “My hemoglobin A1C is under 7 [mmol/L]. Why am I still getting injections? Why hasn’t the DME gone away?” What I’m seeing in the retina at any given point is more reflective of what their hemoglobin A1C was maybe 3, 5, or 7 years ago. In that small cohort of patients, we can persuade them to change their lifestyle and do the A, B, C, D, and E that Joe mentioned. In that small minority of patients, it takes years to turn it around—maybe 2 or 3 years. We had the Diabetic Retinopathy Study Research Group, protocol M, look at diet and blood sugar control, and over a year it didn’t make a difference. It takes about 2 to 3 years for these lifestyle modifications to turn things around. You must be encouraging to your patients, tell them they’re still doing the right thing, and that they must stick to it, that it will pay off in the end.
Let’s talk about actual treatments. Joe, we’re going to turn to you to outline the standard-of-care treatments that we have for patients with diabetic macular edema, then jump into them in detail.
Joseph M. Coney, MD: Over time our treatments for diabetic macular edema have changed. For the past 25 years, the gold standard was focal or grid laser, and we had strong evidence that treating these aneurysms outside the [INAUDIBLE]—that was the definition that we used to guide our therapy—reduced moderate vision loss by about 50%. Over the past 10 to 12 years, we gained more evidence that the treatments they were using for other diseases—such as macular degeneration, because there are similar things that make A and B worse that we notice in diabetic disease—could be beneficial in patients with diabetes. The landscape began to change to more biologics. These were intravitreal injections that we’re placing in the eye. These have changed the landscape of how we preserve and improve vision depending on the permanent damage done to the eye. Sometimes the best we can do is preserve vision, although we hope to try to improve everyone.
There’s a subset of patients whose disease early on may be more VEGF driven—those are the agents we use for the eye. There may also be an inflammatory component where the disease switched from a vascular endothelial factor, or VEGF factor, to an inflammatory factor. We have drugs that treat those as well. There’s still a role for focal laser therapy, but the individuals we typically reserve laser for are those who have non-sight-threatening swelling in their eye.
Nancy Holekamp, MD: Thanks to all of you for this rich and informative discussion, and thank you for watching this HCPLive® Peer Exchange. If you enjoyed the content, please subscribe to our e-newsletters to receive upcoming Peer Exchanges and other great content right in your in-box.
Transcript edited for clarity.