Recommending Endothelial Keratoplasty

Neda Shamie, MD; and Jonathan Crews, DO, join Marguerite McDonald, MD, FACS, to discuss endothelial keratoplasty. How do DSEK and DMEK differ?

MARGUERITE: Welcome. I’m Marguerite McDonald of Ophthalmic Consultants of Long Island in Lynbrook, New York, and this is Informed Consent: Getting to Yes. In this podcast, I discuss the exact, fair and balanced language that leading ophthalmologists and eye surgeons use to help patients say “Yes” to the recommended treatment or to premium services. Today’s topic endothelial keratoplasty, specifically the differences between DSEK and DMEK.

NEDA: But, doing DMEK really allowed me to establish myself as a cornea specialist when I moved to Los Angeles. As you can imagine, there are some really wonderful corneal surgeons in Southern California and Los Angeles, but none, really, were doing DMEK. And, I found that to be an opportunity for me to provide a kind of an elevated level of service or corneal surgery to patients that were, that was not being offered in L.A.

MARGUERITE: That’s Dr. Neda Shamie of the Los Angeles-based Maloney Shamie Vision Institute. She is expert in advanced corneal transplantation as well as a cataract and laser refractive surgeon.

And this is Dr. Jonathan Crews, a cornea and refractive surgeon at Pepose Vision Institute in St. Louis, Missouri.

JONATHAN: I think, once corneal surgeons have mastered DSEK, then moving on to DMEK, it's much different. It's much like the transition in cataract surgery to phacoemulsification. There were early adapters, but it was a slow adaptation. I think that's analogous to endothelial keratoplasty and transitioning from DSEK to DMEK.

NEDA: Yes, the learning curve is steeper. Yes, the complications, initially, before we really had standardized the techniques were greater, but the vision is, without a doubt, better. Frank Price and Mark Terry and others have published on their large clinical trials, and many have actually validated those. But, far more many DMEK eyes reach 20/20 vision than DSAEK eyes, and they reach that level sooner.

JONATHAN: It does take a lot of time. Even when you feel like you've become skilled, there are certain cases where you wonder why you're struggling with doing the procedure. Ultimately, we’re in medicine to help the patient. We know that the results of DMEK provide better vision and lower rejection among the many other advantages to the procedure. I think it is worth the effort and worth the time that it takes to put in to master the skills for DMEK.

NEDA: And then more importantly, potentially, is that rejection rate is tenfold less in DMEK as compared to DSAEK. So, then it became more than just, you know, I can do this really cool surgery that sets me apart, but also I'm really benefiting patients. I felt really fantastic knowing that I'm offering my patients the best option possible.

My approach now is that any patient—and I really, truly, strongly believe this—any patient with Fuchs Dystrophy deserves DMEK because of the clinical benefits that have been proven over and over again.

There has to be a real motivation for the surgeon to want to go through that process of learning a whole new technique, which is, by the way, very different than many other surgeries that we do. You know, DSAEK, for example, if you do a folded technique, manipulation in the anterior chamber, all of those many anterior segment surgeons are comfortable with the techniques and the instrumentation used for the DSAEK. With DMEK, it’s much harder. You cannot manipulate that graft. You inject the graft into the eye, and you have to do this tapping technique and use fluidics to open it. It’s like nothing else that we’ve done.

MARGUERITE: So, Jonathan, suppose I'm Mrs. Smith, and I've been sent to you by a referring doc, who said, “Oh, Dr. Crews is going to do DSEK for you.” You examine me, and you determine that I'm a much better candidate for DMEK. How would you talk to me about it and get me to say yes to DMEK?

JONATHAN: So, I would say, “Mrs. Smith, you're a great candidate for DMEK." I like to tell patients that DMEK provides better vision and a lower rejection rate. I usually walk through the history of corneal transplants. I'll say, "Mrs. Smith, there was a time 20 to 30 years ago where we did full-thickness transplants, and we used multiple stitches to transplant the entire cornea.” Then I'll walk through and talk about DSEK, and I'll talk about the anatomy of the cornea and the different layers of the cornea and how DSEK transplants part of the inner layer of the cornea called the stroma.

“We've moved into an era where now we’re just transplanting just the diseased layer after removing the diseased layer of the cornea. While this makes sense anatomically, we know that it does provide better vision and lower rejection rates. For instance, in DMEK, around 70% of patients are able to achieve a vision of 20/25 or better versus DSEK. That rate is around 20% to 30% or less. The chance of you achieving better vision is much greater with DMEK. Rejection happens in all organ transplants, and it doesn’t spare corneas, although the cornea is privileged in a sense.”

I usually talk about how full-thickness transplants, the risk is about 15% to 20% over the first several years. DSEK, it's about 10%, hovers around 10%. With DMEK, it’s less than 1%. Not to mention that the patients are able to use a weaker steroid with that same low rate, and the ability to use a weaker steroid allows for fewer complications down the road, particularly glaucoma and needing to deal with glaucoma and higher pressures and needing further medications in the future.

“I think these are the reasons for why you'd be a great candidate for DMEK over DSEK, and I would be happy to do your surgery.”

NEDA: That’s an interesting question, because I kind of don’t have, I have to often, convince them that they're not a good candidate for DMEK and that we should do DSAEK. They get terribly disappointed when I say that. So, convincing a patient about DMEK is not that hard anymore. As I said, most of the patients come asking for DMEK.

What I say is, “There’s two. You have a corneal condition called Fuchs dystrophy, which impacts the cells on the back of your cornea that pump fluid out of your cornea. And the cornea is like a sponge that, when you’re sleeping, especially, it absorbs fluid, and it requires those cells to be able to pump the fluid out. Otherwise, you wake up, and you’re looking through a fog. If your cells are not functioning, that is what happens, the morning fog.”

Now if the patient has confluent guttae, and it’s not the morning fog but rather the glare at night, I describe the fact that, “The backside of your cornea, where those cells are, have a lot of dead cells that have coalesced and have caused this kind of metallic sheen. The light scatters off of that, and we need to replace those cells. And my preferred approach for you would be what's called DMEK, which is a perfect anatomical replacement of what is affected by your condition. And unlike DSAEK, this will give you a much faster vision recovery. One of the benefits is that the vision recovery would be faster, and the rejection rate is tenfold less.”

“But, DMEK does require a commitment on your part. We will be more reliant on your lying flat on your back, because there is going to be an air bubble in the eye that will hold the graft in place for 24 to 48 hours. You need to lie flat on your back for the first 24 hours, because that air bubble needs to push the graft towards your cornea so that the cells start pumping and basically waking up and starting to attach. Then the second 24 hours, I may still ask you to do that.”

If this patient says, oh, I can't do that, or my back hurts, or, you know, if the is elderly, then that's when we start talking about DSAEK may be a better option.

MARGUERITE: Jonathan, do you mention gas or lying flat or what the early postop will be like?

JONATHAN: Sure, I do. I usually say, “There's a bit more work for you and for me for DMEK, particularly lying flat. Because we’re not using stitches, we need air to push the graft against your cornea, and because it’s a thinner graft, it requires more bubble time, whether you’re using air or gas. I think that the work that you do is worth it, and the work that I do that I’ve done with learning the procedure, is worth it for you as well.

MARGUERITE: Dr. Jonathan Crews and Dr. Neda Shamie, thank you so much for discussing these endothelial keratoplasty procedures with me today. Does either of you have any advice for a corneal surgeon who is on the fence about whether to offer DMEK to his or her patients?

NEDA: Absolutely. There are so many wonderful courses at the meetings. There are also courses offered through the eye banks. I would use the eye banks as a resource. They are, absolutely motivated to work with you, to help transition the surgeon to the right surgery for the patient. They would offer you, potentially, wet lab opportunities. I’d be more than happy to welcome anyone who wants to come and hang out with me for a day in a surgery. I feel so passionate about this that I feel like every surgeon, if you’ve done DSAEK, you have all the skills to be able to do DMEK, and your patients will do so much better.

Potentially schedule the case before a day you would do DSAEK, for example, and ask the eye bank if they would offer you a backup DSAEK graft. I mean, I’m not sure if every eye bank would have the capability to do that, but some eye banks are doing that and are working together with surgeons, especially surgeons who are high-volume DSAEK surgeons, to really help them, encourage them to transition.

And if you don’t end up using the DSAEK graft, you know, you can use it for the next day for your patient, something like that. I mean, you’d have to really arrange that with the eye bank.

MARGUERITE: Thanks for that great advice, Neda. And thanks for listening to Informed Consent: Getting to Yes. I’m Dr. Marguerite McDonald. Please join us again for next month’s edition.