Live Surgical Demonstration: DMEK

During this live surgical demonstration, Dr. Lehmann performs two Descemet Membrane Endothelial Keratoplasty (DMEK) surgeries in patients with corneal edema from Fuchs’ Dystrophy. This demonstration covers donor selection/preparation/loading as well as the surgical steps and pearls involved in this revolutionary surgery.

Surgeon/Lecturer: Dr. James Lehmann, former Orbis staff ophthalmologist (2005) and current cornea surgeon at Focal Point Vision in San Antonio, Texas, USA


DR LEHMANN: Hi, there, everybody. Good morning. I’m Dr. James Lehmann, coming to you live from San Antonio, Texas, in our ambulatory surgical center. Behind me is my staff, getting the patient prepared, and we’re gonna be demonstrating DMEK surgery today. We have two cases. They’re just DMEKs. Not DMEK and cataract. That was a little bit of miscommunication on the title, but two DMEK surgeries. Before we get started, I’m gonna go through a few slides and give you a bit of an introduction, okay? One sec here. One second. I have to turn on Keynote. Desktop. Share. Okay. Okay, so you guys can see the desktop now. Is that good? Thanks. So live DMEK surgery. My name is Dr. James Lehmann, I’m in private practice in San Antonio, Texas, I’m an associate instructor, I’ve had the good fortune to work with Orbis and SightLife many times over the last 15 years, I was on the plane as a staff ophthalmologist for a year, between 2005 and 2006. Before we get started, a lot of you are watching this and getting interested in getting involved with DMEK surgery. So the question is: Are you ready to start DMEK? There’s a few things you have to do first. You have to have experience with penetrating keratoplasty, I would say at least 25, and also have experience with DSEK surgery, so you can control air in the anterior chamber, make incisions, et cetera. The best way to practice is in the wet lab, you can practice donor preparation, loading, and graft manipulation. All of that in the wet lab. All of that is critical before you do your first cases, and it’s better to do it with somebody who has experience and can mentor you. We’re gonna go through a few slides here, I’m gonna do the first surgery, and during the 10 to 15 minute break as they turn the room over, we’ll go through some of the steps of surgery again. Donor selection — here in the US, when we request tissue, we receive a tissue detail form here, where it goes over the parameters of the donor. In DSEK and PK, we like somebody who is young, maybe in the 5 to 10 years old range to 65, days since death to be about 12, 10 to 20 hours D to P refrigeration, 2500 cells, and we like to look at the microscopy to make sure the cells are uniform and small. But older is better in DMEK patients, because the endothelium goes to the outside, when it’s been removed. It scrolls to the outside and makes tighter scrolls, the younger the patient. So 45 is my lowest threshold up to about 65. Pseudophakes aren’t good donors, because sometimes they have corneal incisions that extend into the area you want to prep, and there’s debate about diabetic donors. Sometimes they have a tendency to tear in the preparation process. At first we were doing it in the operating room prior to the surgery, about ten years ago. This works, and it’s done in most country, but in the US, there’s risk involved, in that the corneas are expensive, so if you damage them in preparation, you have to cancel the case, and the hospital has to take the hit for the tissue. So it’s evolved like DSEK did, where the eye bank prepares the tissue. This is from CorneaGen, and they provide it loaded in a glass cannula, stained and marked if you want it. All right, we’re gonna go now to a live screen of me, and we’re going to show you a little bit about the tissue for this case, and then we’re gonna get started. When I receive the tissue, it comes in a box like this. Okay? And here’s the vial. And you can see the tissue right there in the corner. We like to invert it for a while like this, and let it kind of travel down. And then this is the form that I receive on the patient. Like I talked about. Now, what’s nice is: After the cut, the eye bank then takes another photo, and shows us that the cells still look good, it does another count to help show that it was an atraumatic preparation. Now, I do not get the S stamp on my tissue, because when I learned to do DMEK years ago, the S stamp wasn’t really around. So I learned to use what’s called a portable slit lamp. It’s a small microscope like this. To determine the orientation. So I just want to go over this, before we start the surgery. The DMEK always scrolls with the endothelium to the outside like this. Okay? Always to the outside. Never the other way. And so we want to get it in a position in the eye where it’s scrolled like this. Now, we have to determine: Is it like this? Which is what we want? With the endothelium bound? Or like this, which would be bad. You don’t want it to scroll like this. So you’ll see me turn out the lights and use a slit beam. And what we want to see on the slit beam are two rolls like this. Not a big broad roll like that. That would tell me it’s upside down. All right? Let me just check on the team. Everybody good? Everybody’s good. So we’re gonna get started here. We’re gonna keep you here on the webcam, and once we get started, we’ll switch to the microscope camera, okay? We’re doing a timeout? Right eye? Fuch’s dystrophy? Very good. This patient is a 75-year-old female with a history of Fuch’s dystrophy. She’s had cataract surgery, which is why we’re just gonna do DMEK today. It’s not there? Okay, one second. We’re just gonna coordinate the transfer of the video image here. Go to Zoom. Okay. I’ll just re-glove, if you take that off of me. Now we’re switching to the OR camera. Putting a new glove on, guys. There we go. And we’re gonna get the eye under the camera here nice and centered. And you guys will be telling me — Tom, you can tell me, and folks — if I get out of center, let me know and I’ll recenter. Are you doing okay, there, ma’am? Patient is doing well. How does that look, guys? Pretty good? Okay. All right. So… You guys can get the room lights. So I like to start the surgery by first putting in some traction sutures. This is a little unusual. You’ve probably watched DMEK videos and not seen this, but it allows us to rotate the eye if needed, which isn’t always necessary, but can be critical if you have a difficult case and you’re trying to center that DMEK lenticule. So now I’m cutting the suture and I’m gonna use some 0.12s and tie it and put it off to the side. Here we are right here. Tie that into a little knot. And moving off to the side. This is a 4-0 silk suture on a tapered needle. It’s not a cutting needle. A cutting needle is kind of dangerous in this situation, because you can go too deep. We want to take an episcleral bite about 3 millimeters posterior to the superior and inferior limbus of the cornea. This is just enough to be able to control the eye and rotate. In between the surgeries, I’ll show you some videos of other cases, in which you can kind of see why this is useful. There’s different ways to do DMEK, so what I’m gonna demonstrate today is based on what Frank Price taught us years ago. I can’t take credit for the technique. And it can be helpful to have these traction sutures. The next step is to mark the central 8 millimeters of the cornea. When I order a cornea from CorneaGen, I specify what diameter I want, and that depends on how the diameter of the cornea comes out. This patient had a normal cornea. In a lot of places, the corneas are smaller. I’ve visited India and China, and sometimes 7.5 would be a better choice. So we’ll center the DMEK graft, and I’ll mention one thing here — you can see an inferior iridotomy. That was done with a YAG laser prior to surgery, and it’s gonna be helpful for air bubble management. You can do that during surgery with a vitrector and easier in my opinion — and more economical in the US to do it preoperatively. I’m gonna fixate the globe with 0.12s and enter the anterior chamber at 45 degrees from where my main incision will be. Do the same over here. And I don’t want these tunnels very long, because if they extend into that area that I’ve outlined, it can interfere with the bubble placement later in the surgery. Put some BSS on the cornea. This is a cohesive viscoelastic. And I like to remove Descemet’s under viscoelastic. I suggest for your first cases that you do that as well. You can do it under air. It just can be difficult and tiresome to maintain the chamber depth. So now I’m gonna make my main wound. With the CorneaGen cannula, we can enter the eye with a 2.4 incision. This is a 2.65. I’m gonna make it not quite as big as I can with that. And this is a reverse Sinskey hook. Any Sinskey hook can be made reversed, if you just bend it with some needle drivers. And what I’m gonna do now — I’m just demonstrating it — I’m gonna score Descemet’s membrane to remove it. I’m gonna start here, following my marks, and I’m applying enough pressure to gently whiten the cornea, but not so much that it’s a jerky movement. If you push too hard, you go like that, and you can’t move it. So you just want to kind of glide. I like to go around two times and kind of ensure I have a nice area that’s been scored. And then I go across the anterior chamber. And then you can see the edge that I’ll get here. You can see that edge, and I’m gonna peel the cornea in just nice, gentle motions, keeping an eye on the lateral aspects of the removal, to make sure that the whole guy comes out in one piece. And when I remove this, you’ll see how the view to the iris improves tremendously. The Guttata — not just the edema can affect the vision. And that’s part of the reason why you remove the patient’s endothelium. And why even just a few central guttata can be problematic. So now we’re removing it, and it comes out in one nice big piece here. And if you wanted to, what you can do is kind of… It broke in half there. You can put it on the cornea and kind of unfold it. But I know I got the whole thing there. I’m gonna give it to the assistant. There we go. Yeah, okay. So now I’m going to remove that viscoelastic. And the way we do that is just with an I and A handpiece, from the phaco. Okay. A lot of it kind of slid out through the main wound. And now, while I’m doing this, I’m looking around for any tags that might still be there, because they would be problematic in getting the new graft to adhere. But there’s no tags, so I remove that. And we’re now gonna get the donor ready. So can you get the room lights for me, guys? I switched to a back table here. Just what I’m doing, while you see the eye over there. And it’s on this back table that we’ll kind of prep the donor. It’s already in the tube. We just have to rinse out the current solution and put in some — replace it with BSS. So I’m turning the light down a little bit, because it can get very bright with that reflection. Let’s see. Come right here, actually. And you can’t see — I’m just removing the plastic sled from the bottle, and I’m putting it down right here. I’m gonna zoom out for you guys so you can see this. Okay, so now we’re zooming out, and I just placed — in a big petri dish — this is the way it comes from the eye bank. So there’s a glass tube here, there’s the DMEK all scrolled up in blue already, there’s a cap on this end. I’ll brighten it up a little bit. There’s a cap here and a cap there. And that pinkish hue is the Optisol. So I’m going to remove — first I’m gonna take out the glass. I remove that sled that it lived in. And now it’s just a glass tube there. You guys can see okay? Or is there too much glare? All right. I know what I can do. That’s better, maybe? Too dark? Was before better? Okay. So now what we want to do is… It’s already ready there. It’s in the neck of the device. There’s not much Optisol in there. So I’m gonna go ahead and load it. Now, how do I load it? You use a 3 CC syringe. That’s what this is right here. And then it just attaches nicely to the back end of this, and then I can flush a little bit more of the Optisol out, without… So now I’m just… Making sure there’s no bubble there. I’m gonna attach it via Luer Lock to this syringe. Lift it up, concentrate here, and I’m gonna put just some gentle flushing here. You can see some stuff come out. That’s the Optisol. So it’s all ready to go. Right there in the neck. Maybe go a little bit more. Right to hit that peg. We don’t want to hit the peg. So we’re good to go. I want to make sure it’s nice and attached right there, and I’m handing it over to our little scrub tech desk right there, and then I’m gonna turn my attention back to the patient, and just look at the anterior chamber here, and kind of get zoomed in again. Lights off, please. All right, now, some BSS on a cannula, please. So what we’re gonna do is we’re going to… Fill the AC a little bit. You can see it’s a little flat. And there’s some heme kind of floating around. So I want to get some of that out. We don’t want any fibrin or heme in the AC. Nice and clear now. Okay? I’ll take the cornea. And here’s my little device. I’m gonna hold the Luer Lock, and hold the little peg in the front. Now you can see the injector. See it’s beveled. I like to go bevel-in. And that’s good. Now it’s perpendicular. That’s what we want. So that it doesn’t come out. And now I’m gonna place one suture. Normally a 10-0. Right through the main wound. Before I do any manipulation of the donor. It’s very delicate at this point. That little guy can still slip out easily. Especially if there’s any significant fluid in the anterior chamber that escapes when you place the suture. So I’m gonna just… Make sure I’ve got enough tail here. I’m gonna cut this and then I’ll tie it. Okay. So these are just straight ties. BSS on the cornea for me. Okay? Now of course a 3-1-1 knot like we normally do. Moderately tight. Not too tight, because the eye is very flat right now. And a 3-1-1 knot. I’ll cut that and bury it. Okay, and now begins the positioning, and then confirmation of the orientation. This is a big 10 CC syringe with BSS. And what we have to do now is we have to unroll the graft. And then we have to unfold it. Okay? So first we have to unroll it and verify its orientation. So how do we do this? Well, you manipulate the depth of the chamber and you use bursts of fluid to get the little guy to unroll. It looks pretty scrolly right now, just a word for it being tight. You can see it’s opening a little bit. But when we get it open, we have to shallow the chamber. So I’m using bursts of fluid, hit on the iris, and I’m gonna shallow the chamber through the main wound. It’s a little bit off-center right there, but it’s in the correct orientation, I believe. So if I flatten the chamber now… And then I tap on this little guy, I can get it to unfold. Okay. Now, the question is… What the orientation is. And I want to get it to unroll a little more. But it’s kind of not agreeing. It’s being a little awkward and wants to stay tightly scrolled. So I’m gonna shallow the chamber a little more. And then I’m gonna tap on it, perpendicular. Get it to unroll a little bit, and see if I can determine the orientation. Okay, let’s see. So I’m gonna turn out the lights here, and just use my little flashlight, and I can tell it’s upside down. So now I have to evert it. I have to flip it. How do you flip it? I shoot water underneath it, and it comes around the angle and makes it flip in the right direction. I got it to flip. Now it’s in the correct orientation. But it’s all scrolled up again. You have to be really careful. Because whenever you let fluid out, it’s gonna come to wherever you let it out. I’m gonna expand it here, take some fluid out of the AC… So it’s being really scrolly. Okay. I think we’ve got it in a good orientation, perhaps. But I have to let some fluid out. Let’s see. If I can get this fold out… It’s folded almost in half. That makes it very difficult to unroll. So I’ve got to kind of get it again. Got to be patient. That’s what we like. We like that trifold hat orientation. So we’ll shallow the AC. Kind of tap on it a little bit. And then we’re gonna see if we can… Determine the orientation again. And still unfortunately in reverse. So I’m gonna flip it again. This would be what we would want. Like this. But we need it in the right orientation. We got it flipped. Now I’m gonna inject some fluid into it, and get it… The chamber gets real deep, and then it can just scroll up really easy. Try to inject some fluid into the scroll. Okay. Still too scrolled up. Okay. That’s what we like to see. Like that. But it’s… Move it to the center and see the orientation. Still upside down! Huh! All right, guys. Not wanting to cooperate. There we go. I know it’s in the right orientation now. I just flipped it. Let’s try to get it to unscroll a little. And confirm the orientation here. All right, so… Nope, upside down. Always on the live surgery. That’s what you… All right. Now, this is in the correct orientation. I can see. But I’m gonna confirm by… You can see a single roll right there. That’s one roll. That’s too. The thing is, it’s a little too scrolled up. So I need to flatten the AC, and then just… I want this to come here a little bit. So I’m gonna tap like that. Get it a little unfolded more. Okay. Now, to get my little… Now what I want to do is put a small air bubble underneath it. And for that, I use a 30-gauge needle like this. And I’m gonna try to edge it underneath here, and then give just a little bit of air. And this is gonna help me to be able to unfold it. Not to unroll it. We’ve unrolled it. So I put a little bubble under it, and now we’re gonna fill the AC with fluid. And now… We have the graft. And we’ll try to knock all that… Now, here it’s completely unfolded. But here there’s a fold. So this is where the sutures come in handy. Because I can use that air bubble to help me unfold it, okay? And so the way we do this is we rotate the eye, so the bubble is going uphill, and I create some space, and then I’m able to unroll it. Now I have to have this guy into these little marks. So I rotate the eye this way and then I’m doing some golf swings — or cricket swings. Whatever you like to say in your part of the world. And you always want this bubble as much in the middle of that so that it doesn’t slip out from underneath it. And so now it looks like we’ve got it pretty well centered. It’s in those marks like that. And now we can put a full air bubble in. And then I’m gonna leave the eye firm for about 45 minutes. And then we take enough air to clear the iridotomy. But now what I’m doing is I’m going underneath the graft, and I’m gonna try to join this bubble with what I had done before. There we go, all right. So here’s the outline. I know it’s all good. And now I need to fill it a little more with air. Because if I touch the eye, you can see it’s still kind of soft. So this is what I do. This is kind of a trick, where you put just the tip of your cannula into your para, and you do a small burst. And then we check the pressure. I’ll check it with my finger. That’s pretty good. I’m happy with that. So we’re pretty much done. So what I’m gonna do now is I’m gonna cut these traction sutures. And then the patient goes to the post-op area for a while, and then I’ll check her again in about 45 minutes. So thank you very much. All right. So Tom, if you’ll switch to the main screen… Facetime HD. Okay, everybody. So we’re all done. Taking off my gloves now, and now the staff are gonna turn over the room for 10 or 15 minutes, and I’ll be able to go over some slides with you and answer any questions you have. I see there’s one in the Q and A there. And then we’ll do the second case. All right. So one question… Dr. Sharma sent in a question saying: Can staining be tried to remove Descemet’s? In the case of Fuch’s corneal dystrophy, the Descemet’s won’t stain if you put in Vision Blue. It won’t stain a healthy endothelium or one that hasn’t been injured with trauma. If it’s pseudophakic bullous keratopathy, or trauma, it’ll stain. But in a normal eye or one that’s only had cataract surgery, the blue doesn’t help you to extract the membrane, so it’s not really necessary. Now I’m gonna switch back to my slides and go over a few other tips involved in preoperative evaluation and other tips to go over the steps of surgery with you again. So I’m gonna share my Keynote. So here we are again here. And now we’re gonna talk a little bit about preoperative evaluation. How do you pick a patient for DMEK surgery, basically? The preoperative considerations: Do I do DSEK or DMEK? What type of anesthesia do I use? How well are they able to cooperate, and should they lay face up after surgery? You can see the pain scale here. That’s for the surgeon, not the patient. If you choose the wrong case, you’re gonna be in a lot of pain. So you want to choose a straightforward patient. There are four things to consider. The complexity of the anterior chamber. Are there peripheral synechiae, is the chamber shallow, is there a valve in the eye, angle closure, small eye, vitreous prolapse, ACIOL, any of these things. If the answer to any of those is yes, you probably want to do DSEK at first. But the only true contraindication is ACIOL and being aphakic. Is there scarring? Edema? Haze? If it’s just edema and haze, what you could do is bring the patient in a few days before surgery and do a superficial keratectomy to see how well the view improves. And you have to be able to manage the bubble. So if there’s iris defects or the eye is hypotonous, it may be difficult to manage. Iris defects make that very difficult. And there’s the lens status. Do you combine with phaco or do them separately? I like to do them combined when the patient needs cataract surgery, but it’s perfectly reasonable to do them sequentially. In summary, to plan for DMEK, you need to talk about anesthesia. I like peribulbar anesthesia in these cases. I like to make sure the patient doesn’t have any neck or back problems that would preclude their ability to lie flat. Also they can’t be really skittish and squeezing. Because sometimes you have to put a bubble in the eye, in the clinic after surgery, if there’s a detachment, and you want them to be able to go through that. Who are the easiest patients? Fuch’s dystrophy patients. And like I said, avoid complex anterior segments at first. And do peripheral iridotomy if you can beforehand. But sometimes the view isn’t good enough and it has to be done in surgery. What instruments do you need? Basically a cataract set. Reverse Sinskey, a 10 CC syringe, and a 30-gauge needle. I like to use a cohesive viscoelastic like Healon. You do not want a dispersive viscoelastic, because you won’t be able to get it all out. Here’s that critical instrument I talked about. Or you can use the S stamp. That’s reasonable too. Again, here’s talking about the conformation. The shape that we want is this one, where you see two little scrolls. Not this upside down one. There’s a thing called a tricorn hat. We want it in this configuration. For donor injection, all you need is a back table and a petri dish filled with BSS. The Trypan blue could be used if you need to stain it more, but that was stained well enough for the surgery. And to prepare the eye to receive the new tissue, you do the traction sutures and mark the cornea. I like to use 4-0 silk on a tapered needle, and I use just a normal keratome, as small as 2.4 millimeters, and you need the 15-degree blade to do the paras. I like it more than MVR, because you can control the size better and the depth of the tunnel. I also use the phaco pack and irrigation/aspiration, but you could use the Simcoe for the viscoelastic if you needed to. We’re walking through steps of surgery. These are the traction sutures I just did. Again, about 3 millimeters posterior to the limbus, just fixate the globe with the conj or episclera, and that’s where you make the bite. Traction sutures. Marking the cornea, pretty self-evident. And the incisions here — you want the tunnel to be just shy of where you have it marked for the graft. If you go inside, if the tunnel extends to here, when you inject the air, you’re gonna inject it between the DMEK and the posterior stroma. So this is a case of a combined phaco/DMEK. Sometimes I use an artificial anterior chamber, when I used to use an IOL injector for the DMEK, but nowadays it’s not necessary, when you can use the glass cannula. And then removal. Let me go back there. Sorry about that. So removal… What we like to see is you want that nice edge. And you want to have scored it twice and then grabbed from outside your dots, making sure you’re not getting tears and remnants over in the sides. And just gentle scratching movements. It’s nothing real forceful. You notice you’re not seeing white. If you push too hard, you’re gonna leave gashes in the posterior stroma, and it’s gonna be difficult to get the DMEK to stick, because it’s gonna be an uneven surface. This is a combined case. You can see the reflex is very good through the artificial lens now. I had just done the cataract part. I don’t use any special instrument other than the reverse Sinskey, and you like it to have that rounded tip to it. It doesn’t have to be sharp like a chopper. And these are the surgical steps. There’s three parts. There’s the injection of the graft, there’s suturing the wound, and then there’s the dance to get it in the right position, unrolled and unfolded, and then you place the bubble underneath. Now, to inject it, there’s different ways, right? The glass cannula to me is the most elegant. And I think it’s the least traumatic to the tissue. It can go through the smallest incision. But plenty of surgeons have good results using different kinds of IOL injectors. I used to use an IOL injector, and once I was exposed to this through CorneaGen here in the US, it became my go-to injection. So the dance consists of four, four and a half moves. Okay? The first is to be able to flip the graft. So to flip the graft, you have to inject fluid underneath it, to rotate it. You also have to learn to unroll it. That’s done by shallowing the anterior chamber, and tapping on the cornea. Then you have to confirm orientation. That’s either done by getting an S stamp done preoperatively, or using that handheld slit lamp. Then once you have a bubble underneath it, you want to unfold it. And there’s two types of folds we’ll go into. Lastly, you have to center it. Now, different surgeons use different techniques, some surgeons center the graft before they unroll and unfold it, but to me, this technique can be done in any type of eye. Can be done with a deep chamber, a shallow chamber, whereas if you have to center it first, you rely on the ability to collapse the chamber in order to be able to unfold it. So that’s a flip. You saw that right there. I went through my paracentesis, we’ll show that again, I inject fluid underneath it, and flip it. Do paracentesis, fluid underneath it, and flip. That’s a critical move. What you’re doing is just directing the current around the graft and catching it like a wave. And then to unroll — so once you have it in the correct orientation, to unroll it, you have to shallow the chamber, and then you tap on the cornea to get it to unroll. Some people use two cannulas. Some use perpendicular versus parallel taps. But the bottom line is that if the chamber is shallow, you’re able to unroll it. Now, this is another technique, in which you release aqueous. We release aqueous in order to get it to come out. So you saw here… I’ll replay that video. Instead of tapping, what I do is I go through my main wound, and I’ll let fluid out, and that fluid draws that edge out. Then I tap it a little bit. More fluid out. And then I have that perfect tricorn hat configuration. So the next step here is to confirm, and then we’re able to go. Again, the confirmation steps. And here you might be able to tell: We shine the light on, and you see two bands. One here and one here. Instead of one giant band. By seeing those two bands, you confirm that the graft is in the right orientation. One small band here. One small band here. Again, the two bands, instead of the long single band. So three times I thought I had it in the right orientation, but it was upside down in the last case. And we talked about the orientation. They’re bringing in the next patient now, but we still have some time to finish this. I place the 30-gauge needle underneath the graft, and inject about 0.4 CCs of air. And that allows me to then unfold the graft. Here I have an assistant. Sometimes they can push there if needed. So to unfold the graft, first you inject that small air bubble underneath it, and then you fill the AC with fluid a little bit. Here we go again — just another video of going underneath it. With the 30-gauge cannula. But the needle is smaller. All right. And then… How to unfold it? So there’s two types of folds. There’s one called a point lock fold. You can see here where there’s an edge to it, and an angle, and one is a rolled fold. Just one long flat thing here. So with the point lock fold, you tap there and it will open up. With the rolled fold, you have to use the traction sutures and rotate the eye so the bubble is going uphill, it creates space in the cannula between the bubble and the fold. The only situation in which I have to start over is when the graft gets stuck in the angle. So here’s a rolled fold, that long single fold. There’s one right here. So I rotated the eye away, and put the cannula between the bubble and the edge, and then it came back up. I filled the AC a little bit right there, and then I pushed down here, causing the bubble to go posteriorly, and then its motion, coming back, creates a ripple that unfolds it. So now this graft is pretty much unfolded, and then what we would do is rotate the eye and center it and bring it to the middle of the cornea. Here’s another rolled fold. So again, you see that long flat edge here. Rotate the eye. All right, and then we’re using the cannula here. And we’re having the bubble come back up to the edge there. Okay. Now, a point lock fold is a little bit different. We can still rotate the eye away, but then you can just tap it, and it’ll open up like that. A little bit easier. And we use golf swings to center the graft. We rotate the globe so the graft goes downhill, and then broad strokes. You don’t have to center it as firmly as a DSEK. There it’s completely unfolded, rotate the eye so it’s in the center of the graft, and gently nudge that to the middle. And wait ’til we get it centered in our little dots, and we’re good. Okay? And then the last step is we have an air bubble, we have the graft, it’s centered, and we need to put a full air bubble there. We go back with the 30-gauge needle, back through our incision, we try to join up with our original bubble, and fill up the eye like that. We know the graft is attached all the way around there, and if the eye is firm enough, we stop there. But if it’s still soft, we inject some air through the paracentesis. Here are all those moves together. We’ve got a good configuration, we think. No, we have to flip it. Okay. So now we’re gonna unroll it a little bit, by… There we go. Still kind of making it dance around. We shallowed the AC there, and now we’re gonna confirm to see if we have those in the correct orientation. We see two independent bands instead of one long band. I go under with a 30-gauge needle, try not to distort the iris, put that bubble there… All righty. So now we have the bubble. And now we’re gonna fill the AC there, there’s an assistant helping me, and we’ve got a good sized bubble. We just tap on the fold and it’ll start to unfold on its own. Nice there. Same with that point lock fold. We couldn’t get it just with that, so we’re gonna rotate the eye, use gravity to help us. All right, so now we’re basically unfolded and centered, and now we’re gonna make the big air. So we go back, we join up the bubble, just made a separate one, and now we have a full air bubble. If that’s enough air — how firm do you want it? Fairly firm, in the 30 to 40 millimeter range. If it’s not full enough, you can go through a new incision, or you can go through the paracentesis. Get the eye firm and we’re done there. The patient lies in the post-op area for 45 minutes, and then we bring them back to the operating room and this is what we do. We go through a new stab wound and we inject some fluid in order to create a meniscus, and we want to remove enough air to clear the inferior iridotomy we had done previously. The eye can be fairly soft, as long as this covers the whole diameter of the graft. I don’t gown up completely, but we prep the patient again, I use sterile gloves, and we inject the patient with a 30-gauge needle. If there’s a epithelial defect, we put a bandage lens in place, and then we patch and shield, peribulbar block, and see them again. I always call them the night of surgery. That’s Alto Mayo, for any Peruvians in the audience. This concludes the presentation of it. I’m gonna switch back to the Facetime cam, and we’ll answer any questions before starting the second surgery. So we’ll go to Facetime. We’re good there. You guys feel free to type in some questions. There’s one here. Dr. Sujet Kumar says: Can we use the S mark on the donor Descemet’s for proper orientation? Yes, of course. It makes life easier. The thing is: Any preparation done in the eye bank prior to surgery does run the risk of killing epithelial cells, and since I’m used to using the slit lamp, I feel like it’s an extra step I don’t need. But if you’re preparing, by all means doing it. You can gently touch the posterior stromal side of it with the S mark and be able to mark it. I watched live surgery at Keracon last year, and they can prepare the graft in 10 or 15 minutes during the surgery. In the US, it’s evolved where we receive the tissue already prestained, premarked, and prestamped, if you want. And that takes a lot of the time. So there’s a question here from Dr. Moreno. It says: Any experience on DWEK? Similar results? That would be Descemet stripping without endothelial keratoplasty. This would be someone who only has central guttae and no pseudophakic bullous or anything like that. Just where the central part of the cornea has guttata. And you peel it, instead of using the reverse Sinskey hook and scraping it. You do a reverse Descemetorhexis. It can take months to clear, but they have good results, with the ROC inhibitor. It’s a reasonable thing to do if you have the right patient, and they have the right mindset, they don’t mind waiting, or maybe are okay to undergo DMEK. In the US, we have patients who cannot receive tissue because of their religious beliefs, and I think it would be an ideal situation for somebody like that. Another question by Dr. Ja. He asks: Have you tried system Sarnicola’s cannula? I think that could be really great. What you need to do is find a technique and master it. Dr. Sarnicola is a master surgeon. And I’m sure his cannula is great. But I don’t need to put a cannula into the graft to open it. I can do it with external movements. But this is what the wet lab is for. You try different things and find out what works for you. No open questions at this time. We’re pretty much ready here. I’m gonna go ahead and go get ready to prep the patient for the second surgery. Oh, okay, one more question. Dr. Seido asks what is the appropriate size of a DMEK graft? In a corneal diameter of 12 millimeters, it would be 8 millimeters. In a corneal diameter that’s smaller, anywhere from 7 to 8. I find that if the chamber is shallow, you must choose a small graft, because you’re not gonna be able to unfold it, if you use an 8 millimeter one. I measure all my patients preoperatively, with white to white, and I use that to determine graft size. But I’ve had a case that I couldn’t get it to unfold, because I chose too large of a size. So what you have to do is you tell the eye bank ahead of time what size graft you want. Very good. So I’ll get ready. So we’ve got left eye, Fuch’s dystrophy, cornea… So we just did a timeout, confirming patient’s name, condition, and side. Hi, this is Dr. Lehmann. All right. What’s his age? No, the patient. 77? All right, guys. This is a 77-year-old male, same thing, Fuch’s corneal dystrophy. And we’re doing the same thing. The DMEK there. Hi, this is Dr. Lehmann. You’re gonna hear me talking. We’re doing that webinar, like I talked about. Can you put the bed down and rotate the feet? Put your chin down a little bit, sir. There you go. Perfect. All right, folks. Now we’re bringing the scope in here. We just gave you some. We’ll give you a little bit more. Everybody in the audience — you guys can see it looks okay. So we’ll get started. Same steps that we did in the previous surgery. Where we used the traction sutures first. These are kind of funny needle drivers. Okay, so just doing the same thing we did last time. Pass those sutures, and then we’re going to tie these off. I’m gonna be talking to the audience here that’s watching the webinar. If you could just try to be quiet, if you have a problem, you can of course let me know. But if you answer my question… Okay. Thank you. So passing the other traction suture. Cutting the needle. Handing it back to my assistants. And then tying the knot on this. Same thing here. And then the next step… Of course is to mark the cornea. Get that guy centered for you all. A little extra BSS. Can I have the 0.12? Just gonna center that a little better. There we go. So you can see the pupil’s displaced a little bit, just gonna go for the geometric center of the cornea. He has a big cornea, as you can see. That’s 8 millimeters, and there’s plenty of room for my paras, where I won’t hit the tunnel. Or the potential interface. And now the next steps, of course, are… Paracenteses. We’re gonna make the main incision here. We like them 45 degrees to either side, anterior enough to avoid conj… Cut it in the plane of the iris, but not so long as to go into our interface. This is that viscoelastic. Some BSS on the cornea for me? Main wound… So we just fixate the globe with… Okay. So we’re right at the limbus right here. Shallower than I would a phaco wound. Not as long in the tunnel. And then we’re gonna use the reverse Sinskey hook. Adjust the speculum a little bit, so that fluid doesn’t accumulate. Okay. And so now we’re gonna remove Descemet’s. I’m going to put a little more viscoelastic. You can see how the iris kind of popped forward right there. There we go. And so again, a lot of docs do this under air, and that’s perfectly fine. Especially if where you live, viscoelastic is prohibitively expensive. But I feel like you can use the main wound, it’s kind of easier and more stable to do it with viscoelastic. But you can do it under air, and you can even inject air, if you have areas that you aren’t sure that the recipient was removed, you can put in some air underneath the viscoelastic, and it will stay in the eye and kind of show you stuff. Pliers, and now we remove it. That’s the last bit. I and A. So now we use I and A handpiece to remove the viscoelastic. We see a real tight fit, because I made a 2-4 incision. All right. Now I’m gonna use BSS, please. Just want to kind of confirm all the viscoelastic is out. So the way I can do that is to inject a little BSS, and see if I can deepen it. See if anything is floating around. I don’t see anything. I’ll try to shallow the chamber. That’s about as shallow as it gets. And I want to just fill it right now, before I go turn my attention to the donor. So I’ll take the donor cornea. If you can turn the room lights on for this part… Okay. All right. So now off-camera, I’m just pulling that little sled into our petri dish. I use forceps for that. Okay, so let’s see what we’ve got. We can see the sled. You can see the glass cannula with viscoelastic, and you can see the donor is kind of stuck up on this end, so I’m gonna take the cannula out of the sled. We want this little guy to go downhill a little bit. So I’m gonna get it away from there. So I’m gonna lift it up, and then I’m gonna use a little bit of fluid like this to kind of get it to go downhill. So you can see it starts to fall a little bit in the cannula. The glass cannula. So just getting it away from that top, because I don’t want to take this off and by accident pull the… Now I can attach this. And those look like little bursts. I can kind of gently nudge it down into the cannula, and at the same time I’m getting out the Optisol. Just little nudges like that. All right. I have to put more BSS in my 3 CC syringe. I’ll just use this. Got it. And where do we want to get it? We want to get it just to the neck right there. Beautiful. So I’ll give this to my assistant. And then we’re good. We’ve got the donor in the right position. And then… Turn our attention to the patient. And get the room lights. And then just zoom in and focus. Okay. So a little BSS first. What am I doing here? I’m just gonna fill the AC. So it doesn’t collapse. And I’m gonna bring our little guy in. And have a cannula on stand by for me? So we’ve got our little guy bevel up here. Okay, now… See that cannula? Here’s a… Cannula please. So what I’m gonna do… If I withdraw this, there’s a chance that this guy could come with me, so what I want to do is rotate him perpendicular to my incision, or at least away from it a little bit. There we go. So now he can’t come out. Now I’m gonna suture my wound. And you notice I kept the cannula in the wound. If I take it out too fast, I run the risk of expulsion of the donor. All right. One, two, three. And not too tight. So that may be a little tight. That’s pretty good. Because we’re gonna fill the chamber. Of course, I’m tying a soft eye, so whatever I do now is gonna have more effect… Scissors, please. Than when it’s full. Okay. And then rotate that knot. Okay. Get that 10 CC syringe, and now we begin the dance. So again, the first step is to kind of flip it and unroll it. All right. So now it’s starting to unroll a little easier than the first one. There we go. We’ve got that shape we like. So I’m letting flood out. But that folded too much, so I’ll let it come over here… That’s what we want right there. So you see these two rolls like that? And I confirmed that there’s two rolls there, instead of a big broad one. Okay. So small air. Now, it’s not in the ideal position. It’s a little off to the side. But it’s okay. I can flatten the chamber a little bit. And then I can try to unfold it a little more. And that’s gonna give me more leverage. Okay? My 30-gauge. And this is kind of the closest point to enter, to go into it. So this is where I want to go in. You want to use nice cannulas for this, I mean nice syringes, that have good action. You don’t want to go in and end up putting in a huge bubble. I’m trying to wiggle in that incision, the same way that I… There we go. I’m in. Avoiding the iris. I’m underneath it. And then… Okay. So I’ve got a couple of bubbles, but I can live with that. Now we have to fill the AC a little bit. So the bigger it is, the more we can kind of manipulate. So we have two bubbles, just for fun I’ll go ahead and take this little one out. Okay? Now, we have a bubble, we have a graft with a point lock fold, and a rolled fold. The point lock fold is easier. So what do we have to do? I’m gonna rotate the eye this way. And then we’re gonna use the bubble to unstick the fold. By tapping on the fold. So we got that unfolded. Now we’ve got this one. That’s easy. You just tap it. It’s offcenter, so we rotate the eye, keeping the bubble under the graft, and these gentle movements like this, to move it centrally. Keeping the eye where the graft is going down the hill, and the bubble is staying in the middle of the graft. Sorry for the other one getting in the way. I think we’re pretty well centered now. Probably be to me a little bit, so I’m just gonna do like this, so now we have the graft, and we’re gonna use the same syringe, and the same needle, and we’re gonna wiggle our way into that wound again. Go underneath the graft, join with the original bubble. That didn’t join it. Okay. And now we have an air bubble. So now we’re gonna test the cornea here. It’s still pretty soft. So I’m gonna inject air by just going in my para, just a smidge. Still kind of soft. Okay. Not quite the tense… There we go. That’s what I like. So we’re good. Now I take the scissors, move this… And then here. And then we’re all good, so we let the patient stay for 45 minutes. Thank you very much, and we’ll take some questions. Thank you. So everything went great. And we won’t be televising the rebubble stuff, so you guys are good. Thank you. And I’ll just take some questions, and close up the webinar. So that surgery went a little smoother, in the fact that the graft was not as scrolly, and I was able to get in the correct orientation on the first try. So the normal case is somewhere in the middle of those two. But that’s all I have today. So if there are no questions, I would appreciate — just thank you for your attention, and my email address — I can send, and anybody can send me questions. I’ll send it here in the chat to everybody. To all panelists and attendees. This is my email address. [email protected]. If you have any questions… Oh, here’s one. How can visibility be improved if there’s stromal edema? Asks Patrick Idam. Thankfully, you can do DMEK through a pretty terrible cornea. Just remove the epithelium and you can see anything. Using that handheld light pipe can give you a better view of the anterior chamber if needed. But you can remove the epithelium, and you can improve the view that way. You could also leave the epithelium, use saline drops, hyperosmotic drops. That can help as well. But most of the time, it’s very rare that there’s a cornea that we can’t see through. Dr. Jha asks: Any tips to manage unfolding better in a pigmented iris? The things that make unfolding difficult are peripheral anterior synechiae, vitreous, and any kind of fibrin in the AC. So what you would do is: If you have a pigmented iris, with a bad view, after you do the first steps of the surgery, you would do the — use your vitrector with viscoelastic in the anterior chamber, and make an inferior iridotomy. And that will keep any fibrin or blood from spreading over the anterior chamber, it’ll get it to coagulate, and you’re good. A pigmented iris alone isn’t any more difficult than a blue iris to do DMEK on, but if it has pseudophakic bullous and bad things because of that, you may not be able to do DMEK and you have to do DSEK on that. If the chamber is shallow, you have to use a small graft, or a bubble to hold it, but iris color alone is not a contraindication. Any other questions? If not, I’ll ask Lawrence at Orbis if there’s anything else.

>> That looks like all the questions for now. We’ll wait like 30 more seconds, and then if no more questions come in, we’ll close it out.

DR LEHMANN: Sounds good, thank you. Okay. I got a thank you from one of the attendees. Thank you all. I guess I’m going to sign on out. I appreciate your attention. Thank you very much. Bye from San Antonio.

>> Thank you, Dr. Lehmann.

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August 13, 2019

Last Updated: October 31, 2022

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