Lecture: Penetrating Keratoplasty: Preoperative Planning and Intraoperative Steps

During this live webinar, you will learn about patient selection, preoperative planning, and intraoperative steps in penetrating keratoplasty. Regarding the upcoming webinar, Dr. Lehmann stated, ”in spite of advances in lamellar keratoplasty, sometimes a penetrating keratoplasty is the best option for the patient.”

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


James Lehmann: Hi, everybody, good morning. My name is Dr. James Lehmann. I’m here to talk to you about Penetrating Keratoplasty, so let me share my screen. Okay. So, welcome. I’m sure more people are joining right now. It’s 8 o’clock in the morning here in the United States Central Time Zone. This is an Orbis webinar and we’ll be talking about Penetrating Keratoplasty, the planning and the intraoperative steps, so not necessarily the postoperative care, but we’ll touch briefly on that.

A little bit about my about me. I’m based in Texas which is the State there in the map. I’m in private practice but also an associate instructor at the local medical school. I mainly do cataract and corneal surgery mostly in the filial these days and I have no relevant financial disclosures for this talk. Over the last 15 years, I’ve had the opportunity to work a lot with Orbis and Sightlife, teaching cornea transplants across the world. It’s kind of my passion and it’s a pleasure to be here. I say good morning to all of you all, buenos días [foreign language] [00:01:07].

We’ll start with some poll questions. This lecture is basically aimed for beginners. So, we’re going to talk about these few questions and get an idea about you all’s experienced level. So, the first question, I have performed Penetrating Keratoplasty, Never, Under 20 cases, Between 20 and 50 or Above 50. So, go ahead and answer that, okay. So, 68% of you all have never done a cornea transplant and the rest are beginners with the handful of more experienced surgeons. Okay. So, these are pre- elect trick questions. The other one is which of the following is not a contraindication to penetrating Keratoplasty. So, not a contraindication, Active OCP, Untreated exposure, Keratoconus with scar or Active Grass versus Host Disease. Which one of these is not a contraindication? Go ahead and submit your answer. Okay. That’s good. Keratoconus with a scar is not a contraindication.

When performing penetrating Keratoplasty, which of these statements is true? The donor trephination is larger than the recipient or the recipient is larger than the donor. Go ahead and submit your answer. Okay. 83% of you guys got the correct answer there, the donors should be larger than the recipient. And then if the patient has a corneal scar and a mild cataract, the surgeon should perform a triple procedure or the surgeon should perform the Penetrating Keratoplasty and then months later do the cataract or the surgeon should take out the cataract at first and then months later the PK or the surgeon should do a DMEK. Which is the answer?

Again, patient has a corneal scar and just a mild cataract. So, Option 1, a triple procedure that’s cataract surgery Penetrating Keratoplasty, intraocular lens implantation. The second one is the PK followed by the cataract surgery. The third is the cataract surgery followed by the PK, and the fourth is a DMEK. So, go ahead and submit your answers. And okay, so a little bit uncertainty on this. That’s good and we’ll address this later in the talk, so. Okay.

Here are our objectives. We’re going to understand how to choose a donor cornea, what makes a good donor cornea. We’re going to understand how to plan appropriately for PK. And we’re going to learn about the basic intraoperative steps. There’s only so much you can learn about the intraoperative steps from a lecture rather than a wet lab or observing or scrubbing in with one of your senior docs. But we’ll cover some of the basic steps.

So, first background. This is a photo of a patient of mine taken about 10 years ago and you can see it’s a square shaped graft. This was done by Dr. Castillo Javier in New York. So, when I saw this patient, the graft was already almost 50 years old in the patient. And when he got the cornea, he was about 50 years old. So, it was about 100-year-old graft by the time I saw it. Back then, they didn’t have trephine, so they used a double scalpel and made this square type incision using steel suitors or silk eventually. And the patient would have to lay, you know, flat with sandbags around their head in the OR.

Now, it’s a cataract, excuse me, Penetrating Keratoplasty is an outpatient procedure. These are stats from the EBAA and they show, the number of PK is in blue over the last 15 years in the United States which declined from around 40,000 year to around 18,000. While Endothelial Keratoplasty has risen. So, now in the United States more IK or DMEK/DSEK is done than PK. And, so in terms of patient selection, in the US the most common reasons to do PK would be Keratoconus, Corneal Dystrophies and repeat corneal transplants. And this is going to vary country by country. Like I said in the US, it’s Keratoconus and Repeat Grafts, Perforations infections, et cetera. But in India, therapeutic for fungal ulcers is the most common indication. And then the second is the optical graft says redrafted should be for regrafted. So, of course it varies by country.

So, let’s talk about who you shouldn’t do a transplant on, okay. And, so these are patients that you may see in your clinic. And it’s basically people with uncontrolled ocular surface disease. If it’s severe KCS or Keratoconjunctivitis Sicca, the graft isn’t going to emphathilia [Phonetics] eyes. Steven Johnson Syndrome, obviously there’s the acute form in the chronic sequelae and neither situation is it ideal to do a corneal transplant. OCP, you see that picture in the lower right that shows the symblepharon that again is not a very hospitable environment in which to do a corneal transplant. Limbal Stem cell deficiency would need to be addressed prior to doing Penetrating Keratoplasty. And exposure, eyelid exposure needs to be fixed well.

So, a few more contraindication. So, an active infection, unless you’re doing the transplant as a therapeutic PK, you want to treat the infection first. And HSV is a special circumstance or VZV. They need to be on systemic anti-meds — anti HSV meds like Valtrex and the disease has to be quiet prior to doing the transplant. Uncontrolled Glaucoma, that needs to be addressed first so the patient needs a tube before the PK or a graft. And then multiple previous rejections can — obviously each graph has a lower chance of success. So, in this situation perhaps, if they have another good eye doing nothing or if it’s their only eye considering cared of prosthesis.

And lastly, a contraindication for surgery is the inability to care for a PK. So, many of you may have patients who come many hours to see you. They’re not the ideal patients to do Penetrating Keratoplasty because invariably people have problems and they don’t always know that they have problems in the post op care. That’s why you have to see them, you know, pretty steadily until it’s settled. So if they’re very far away or if there’s a mental issue or there’s any question that they can’t take care of the graft, better not to do it.

So here’s a specific indication, Fungal Keratitis. And, so this is not a severe fungal keratitis. This is what we kind of see in the US and we wouldn’t go and do a transplant for this. What we would do is treat this with topical antifungal medicines until it healed up and the scar developed and then do a corneal transplant. And here is a very vascularized failed graft. So, this is probably not the first transplant this patient has had. Now, here you can see is there any viable corneal epithelium, maybe not. No limbal stem cells and maybe conjunctivitis to the whole cornea. So, in this situation, they’re not going to do great with a repeat graft. So, here would be either a KPro or maybe a stem cell transplant from the other eye first.

Sometimes an option for patients with corneal scars is a Deep Anterior Lamellar Keratoplasty. And, so many of you know what this is as you can see in the photo down at the bottom. It’s keeping the patients, you know, back zero or 1% to 10% of their cornea and just transplanting the posterior stroma and it has less chance of rejection and it’s less susceptible to Traumatic Dehiscence. However, it is much more difficult to perform and it’s not always possible. If they have full thickness scar or full thickness injury or history of Keratoconus with high drops, you can’t always do the dissection or pneumatic dissection in order to do the disc, the dark rather.

So, first we’re going to talk about donor cornea selection, okay. So, in the United States when eye order a cornea, a couple of days before the surgery, I get a form like this. It’s from the San Antonio Eye bank, my local eye bank. And it has these pertinent stats there. It talks about the age of the decedent. And when the patient died, we like to use the corneas 12 days or less for transplant. Those are the most successful. And many countries that I visited such as India and China, they use corneas two to three days afterwards. It’s not really an issue. They’re able to use the corneas much faster, so the sooner the better but however 12 days is fine.

The other criteria you want to look at it’s called the death to preservation time. That’s from when the patient died or the decedent died and then the graft was harvested. And you want that to be under 20 hours and you want them to be cool that would be in the morgue for a long of that possible, is possible. And then another important thing is to look at the cell count. And in the US, now we get pictures, so look at the cells yourself to make sure that there’s no guttata and that they’re healthy and uniforms. And also, you need to look at the clear zone because if you’re going to do a larger type graft, you need to make sure that the diameter of the clear zone is sufficient for your purposes. So, this is just a brief version of the donor selection criteria, okay.

Now, where do we get these numbers from? Well, back in the late 90s and early 2000, the donor, the corneal donor study was done here in the United States and they tracked 10 years outcomes of Penetrating Keratoplasty. And it was comparing young corneas to old corneas. They all had decent, they all met the basic EBA criteria for PK that have decent cell counts and the donor ages, like I said we’re from 12 to 75. And at first, there was a big difference in the cell loss. But at five years, there was no significant difference. So, this gave us confidence to be able to use older corneas and that opened up, you know, the number of cases that we could do would be a lot more. And so, the corneal donor’s study was very important in cornea because it showed us that we can have success with older grafts.

Many new cornea surgeons asked, why don’t we match the HLA types like they do in solid organ transplantation? Well, there was some studies done in the 80s, not a lot. They didn’t show any improvement with HLA matching. The same went for ABL compatibility, so this kind of fell by the wayside. And then what do we store corneas in. Well, there’s the short-term storage which is like the M-K medium if you’re going to use it for 48 hours or less. So, it’s cheaper than optics also. Sometimes in eye banks in the developing world, they’ll store the cornea in this until they can see whether it’s viable cornea and has good stats. And then transfer it to optisol or cornisol. In the US, we use optisol and it’s, you know it’s a nice little mixture of stuff that can keep the cornea FDA approved for 14 days.

Then there’s also long-term storage which would be gamma irradiation, cryopreservation but those aren’t going to be viable in ethereal cells. And in Europe, they do more of the organ culture which allows you to use a cornea for a longer period of time. Let’s see here. I’m going to see what the — some questions popping up, let’s see. So, just a couple questions. I’ll get to some of these, there’s a question about how many times a patient can undergo corneal transplant, et cetera. So, we’ll get into those folks. Don’t worry, I’ll answer those questions. So, back to the – one second – back to the talk. Okay.

Now, what about the medical and social history of the decedent? What’s important about that? How about serologic testing? Well, the serologic testing that we do is basically really on viral infections, also syphilis. So, we do hepatitis, HIV and RPR in the United States. Since 1986, when they started doing the surface antigen for hepatitis, there have been no documented transmissions of hepatitis, never was with HIV or RPR. What we don’t get is the HTLV virus, Epstein Barr, Cytomegalovirus, Chavez, West Nile or COVID actually. However, these stats sometimes come with the corneas if the whole, if the patient, the decedent was donating sold organs along with the corneas. Sometimes, you’ll have this information. But we don’t do if it’s just the cornea.

And, so the most common reason to reject a cornea is because it tests positive for hepatitis B or C here in the United States. At the Eye Bank, this is called the viewing chamber. This is what we get are corneas in. And you want to do a slit lamp exam on the cornea. You want to see if it has any infiltrates, if it had previous cataract surgery, what the size of the clear zone is and then of course speculum microscopy. This is critical and you want the picture, obviously they’re on the left. The one on the right would have a lot of cell drop out. You can look for stress lines from being a little too aggressive with the tissue and you just want to make sure the cells are homogeneous, uniform and small. And you’re going to have more success with that cornea. Okay. So, that’s a little bit about patient selection and donor cornea selection.

Now, we’re going to talk about the preoperative planning. So, there’s some different aspects to this, right. So, we’re going to start with anesthesia. We’re going to talk about the lens, see if they fake it or they sure to fake it. We’re going to talk about the special case of the previous failed transplant. So, the goal of anesthesia in any surgery, specifically Penetrating Keratoplasty is you want the patient to not move the eye and you want them to not feel anything. This is very important with the Penetrating Keratoplasty because for, you know, 10 minutes the eyes open and any kind of squeezing or moving or valsalva from the patient can cause expulsion of intraocular contents.

So, the most common way we do the surgery in the United States is under a retrobulbar anesthesia with IV sedation with an anesthesiologist or a nurse anesthetist there in the room. However, in many countries, general anesthesia is the most popular way to do a Penetrating Keratoplasty. And there’s nothing wrong with that. It just may require some additional preoperative health screening that we don’t have to do. So, what you have to do when you’re talking to the patient is assessed, the patient’s ability to lay still during the procedure. Their age, their mental status and if you’re going to have to do any additional intraocular procedures. The cases that I still do under general anesthesia would be if I have to suture in an artificial iris for example or any other kind of hardware where there’s a risk of bleeding. Those, I still do under general anesthesia.

You also have to assess the risk for a suprachoroidal hemorrhage. So, in PK patients, I do stop aspirin or I have them get clearance from their doctor, their primary care doctor to stop aspirin Coumadin Plavix, any kind of blood thinner, I like to stop for a Penetrating Keratoplasty, whereas I wouldn’t if it was a DMEK, a DSEK or cataract surgery. Those under local anesthesia, no issues with continuing a blood thinner but with PK, very critical to stop that. So, Retrobulbar anesthesia, you are all familiar with, you know, you do this for glaucoma cases for other cornea type cases. Here’s some of the problems that can happen. Fortunately, these are very rare in experienced hands and it’s a safe procedure. I also would consider doing a facial nerve block Van Lint, I think it’s called, around the eyelid during a PK if you’re going to do it under retrobulbar anesthesia. So, they can’t squeeze hard during the case.

Now, let’s talk about lens management. Okay. So, there’s some different scenarios here. The first one and the most common one is if somebody has a mild to a moderate cataract. Then if they have a dense to a mature cataract, you do it a little differently. And then these other ones were rare fortunately, things like dislocated IOLs, poorly fit ACIOLs or UGH syndrome which is the Uveitis-Glaucoma-Hyphema syndrome or Aphakia. Okay. So, again, the most common scenario. If they have a mild to a moderate cataract, you leave the cataract alone. And then once the cornea is healed, then you’ve removed some of the sutures to get a good shape to your graft. Then, you do the cataract surgery. And in my hands that would be a Phaco.

Now, a couple of things. Is difficult to do a Phaco under a PK? The view is never as good as you think. There’s some distortion and the depth of field is different in a PK eyes. So, using Trypan Blue to stay in the capsule, getting the dilation as good as you can and having experience with Phaco those are all important. We’re not going to talk about post op care, but I wanted to just talk about it briefly in relation to cataract surgery. So, in my case is, I do a pattern of 12 interrupted and 12 running sutures pretty much on everybody. And then I leave them alone for about four months, and then I bring them in and I do it topography. And I try to find on the topography where the steepest access is. And then I selectively remove interrupted sutures.

So, then I bring them back a month later and then I do the same thing. So, now you can see in this photo that the access of astigmatism is around 75 has eight diopters which is not uncommon. And then you look on the picture of the [indiscernible] [00:18:35] and you see some interrupted sutures in that area. So, I would remove those interrupted sutures knowing that I have that running suture there for added safety. So, if you’re doing interrupted sutures, you’re going to wait at least six to nine months to remove sutures. And you can’t remove adjacent sutures. But if you have a running suture, you can remove them sooner. And, so you do this and then you bring them back in a month. And then we have only two diopters of cells. So, then I’ll stop removing the sutures in this case. And then at that time, I would do the cataract surgery.

Now, sometimes there’s trauma and you would have a mature cataract. So, this was a rupture globes suture at the local medical school. And then I had the patient for subsequent PK. This patient still is doing well. He was 18, 19 when this happened and I still take care of him. He’s grafted surviving. But in this situation, you can’t leave that mature cataract there. So, you would do a PK and then remove the cataract and hopefully the bag is intact and you don’t have to do any kind of gymnastics with the lens. But you could do, one-piece PMMA is a good lens in this situation or a three piece with a silicone optic because you’re not really putting it in the capsular bag to the sulcus. So, I would avoid acrylic lenses, they can chafe on the back of the Iris. I would use a PMMA lens or I would use the silicone lens with PMMA haptics.

In these cases, it’s important to use Flieringa ring. They provide structural support to the eye while the lens is being removed. And I prefer the open sky ECCE techniques. So, we’ll get to that a little later. But basically, in a bad cataract you’ve got to take it out at the time of the transplant. So, here’s that boy after the surgery and again, he looks pretty much the same, the graft to survive, WE hadn’t had to regraft him in 11 years now. So, what’s Flieringa ring? It’s basically a little metal ring and you suture to the episclera and it provides structural support like a kite, like a box kite essentially while you remove the lens. It keeps the posterior pressure from coming up allowing the eye to kind of sink into its place. So, it’s very important to use if the patient is going to be aphakic at any point in the procedure. So, what does that mean, of course, if you’re taking out the lens or if he’s aphakic to begin with.

What if you had a dislocated or poorly fitting IOL? So, if you look at this picture what you see is undiminished cornea with some vascularization. And you see one piece acrylic IOL in the anterior chamber. So, that’s a no-no. In this situation, I would not do this all combined. I would remove that lens and I would either do probably Yamane for sparely fixated posterior chamber IOL and then come back and try to do Endothelial Keratoplasty in this picture. But, so the point of this is it’s better to do a staged technique. You have to do the IOL exchange first. You either suture the IOL with Gore-tex or Prolene or you do Scleral Fixation with glue or Yamane.

Getting a few more questions here, let me check those out. I’m looking here, some more questions. What do we do in case of corneal scar plus severe cataract? So, that’s from Dr. Neral Razik Amalia [Phonetic]. So, in that situation is what I just covered. If it’s a severe cataract, you take it out at the time of corneal transplant. And then how do you reduce astigmatism post operatively? This is from Mogus Saschomi [Phonetics]. Dr. Mogus, well, you remove the sutures. That’s not really the scope of this lecture. But I will do a lecture. I have done one on post-operative management of Penetrating Keratoplasty. Basically, you take out the sutures based on topography until you get a shape that’s stable. And then if they still have astigmatism, you have to do some astigmatic keratotomies at the graft host juncture.

Okay. This is from Dr. Manali Hazarika. What precautions should we take while suturing a Flieringa ring? We’ll get to that shortly here. And then Dr. Chavis Saini asked, in a patient where we’re doing PK before Phaco, do we do the measurements for the IOL before the PK, also do the incisions change while doing Phaco in an eye with PK? That’s a very good question. You do the measurements before the cataract surgery part. You don’t do it before the transplant. The incisions do change. You have to be a little more posterior on your incisions and make sure you don’t disturb any sutures that are still there.

Dr. Jessica Zarwan asks in a dislocated IOL, why don’t we expand or exchange the IOL in the same time with a PKP? It depends on the case, okay. It’s possible that you could. You could do a big surgery under general anesthesia and suture in an IOL. That is okay. But oftentimes, in a dislocated IOL, you’re going to Endothelial Keratoplasty instead of Penetrating Keratoplasty because the problem is corneal edema. And in those situations, doing a combined procedure with like DSEK or DMEK can be difficult. Because if there’s blood in the anterior chamber, if the view is not great, all of these things make it complex to do a DMEK or a DSEK. I have more in this on my talk about Endothelial Keratoplasty. But it is okay to do the IOL exchange at the time of the corneal transplant. But it adds a whole level of complexity to the surgery. And, so you have to be comfortable working open sky. You have to be comfortable making sclerotomies, passing sutures through a soft eye if needed. So, it can be kind of tricky.

And then Dr. Vivek Arya asks, can an Iris fixated lens be implanted? That’s not my preferred choice. I think you’re going to get – I think you’re going to get problems with that down the road in terms of inflammation CME corneal decompensation. It can be if that’s your only choice. But nowadays I would prefer glued intrascleral or Yamane technique for a secondary lens. Dr. Zarwan asks us again, did you recommend cornea laser argon photocoagulation avastin prior to PKP to reduce the neovascularization? You know, that can work but the thing is it always comes back. You have to, if the conjunctiva has grown over the cornea, it needs some sort of limbal stem cell transplant, is more definitive. If it’s just one blood vessel from like a scar from HSV, then that’s a little more doable.

And then another question is, hi, how long would you withhold the aspirin prior to PK? I’d say 14 days. Dr. Rebecca Wudaho [Phonetics] asks, what do you usually do PKP after corneal tear repair with cataractous lens. So, that was like the case that I showed over here. You know, it can wait if the eye’s quiet, it can wait. If the lens material has kind of been released and they have pressure issues and an inflamed eye, then you got to do it a little sooner. But you would wait until the eye’s calm. I would give it like a month or so. And Dr. Gilead Facadoo [Phonetics] asks, how long do we keep the stitch before removal? So, I do it about four to six months but if it’s interrupted sutures only, at least six months.

All right. I’m going to move along and we’ll come back to some of these questions. Good, though. You guys there sending a lot of questions. Okay. So where were we? We were talking about the lens management. Okay, so this is the situation of a failed PK. You got to figure out what’s the best thing to do, another PK, an Endothelial Keratoplasty or KPro. If you’re going to do another PK, you have to decide are you going to trephine in a different location or you’re going to dissect the graft that’s there already.

So, the most critical thing to decide between a repeat PK or Endothelia Keratoplasty is how well the patient saw prior to graft decompensation, okay. So, if they were seeing well in glasses or contacts, then I would do an Endothelial Keratoplasty. But if they weren’t and they couldn’t wear a contact or their vision stunk, then I would do a repeat PK. And you need to look at the severity of the stigmatism, ectasia of the graft, vascularization, etcetera. So, again the take home message for this is if they saw well before and it’s just endothelial failure, then just doing an EK under there, either DSEK or DMEK. But if they didn’t see well and the shape stinks, then do a repeat PK.

So, here’s a situation. You can see a bullous centrally here. You see the eyes inflamed, moderate vascularization but not encroaching on the, completely on the graft. So, this patient had good previous vision. They just basically have graft failure. So, in this situation and Endothelial Keratoplasty is indicated in my opinion. Whereas, in this one look at that, that’s a vascularized scarred graft. If you fix the endothelial on this, it’s not going to make a difference. In fact, you couldn’t even see to do it if you wanted to. But in this situation, I think you have, you know, no corneal epithelium. So, this would be either a repeat PK, a KPro or possibly limbal stem cell transplant from the other eye and then try the PK. If the patient has a good other eye, maybe do nothing. This is a KPro case. You know, this is for a different lecture but essentially in grafts with multiple failures, that’s the best indication for the KPro.

Okay. So, these were some questions about repeat PKs. Dr. Lana Fu from the UK asked any tips for undertaking repeat penetrating keratoplasties? I like to look for the centration of the previous PK. And most of the time, I will re-trephinate. I will not try to strip. It’s pretty aggressive, especially if the graft has been in there a long time and is scarred in. It’s pretty rough on the eye to peel, to rip it out. So, I like to re-trephinate, re-trephine and I like to center it not on the previous graft especially if that one where de-centered but rather on the geometric center of the cornea.

So, Dr. Sherly Indah Puspitasari [Phonetics] from Indonesia asks if the first cornea transplant does not grow, how many times penetrating Keratoplasty can it be repeated? So, I would say maybe three, depends on the reason that they failed. If they failed because the patient didn’t use their steroid drops, that’s one thing. If they were compliant and they had other issues like glaucoma and stuff, it’s going to be much less likely that they’re successful. Every time you have to re-graft, it goes from like an 80% success rate, maybe not 20% off each time. So, this is kind of a judgment call. Ask your colleagues, you can always email me, but generally you got to figure out why the first transplant didn’t work. Primary graft failure, infection, patient didn’t take care of it or rejection, all of those have different prognostic indicators.

All right. So, let’s talk about the fun stuff, the surgical technique. I got about 30 minutes here. All right. So, the surgical technique can be broken down into different aspects. Preparing the recipient, prepping the donor, doing the trephination and there’s some unique situations like a temporary KPro if you’re doing a combined case with a retina colleague, there’s cataract extraction and then we’re going to talk about donors suturing. So, preparing the eye is placing the flieringa ring, measuring the corneal diameter and marking it and then determining the donor size. So, my standard is generally 8.25 into 8.00. I only oversized it by 0.25, not 0.5. I did that — I used to do 0.5 but when I started in private practice like 15 years ago, I felt like my corneas were too steep. And so, I’ve had success with this. And with my combined running intermediate, excuse, interrupted suture pattern, I don’t have leaks.

In many countries, the eyes were smaller than the US, so you’re going to make smaller grafts, probably 7.5 into a 7.25 or 7.75 into a 7.5 are going to be more common. So, here’s a little video showing placement of the flieringa ring, okay. And basically, you want to size, it’s about two millimeters outside the limbus. You can see that area there and then you want to use a spatulated needle. It could be silk or it could be vicryl and they don’t have to be radio passes. They could be oblique. And you just want to get a little bite of the episclera and then of course, in and out of the conjunctiva and then you’re going to tie it to 11 knot. Then you’re going across the eye to the other side, you’re going to do the same thing. And you want to do about four or five of these in order to give good, you know, good stability, good rigidity to the cornea. So, here we go and a little trick. You can keep one tied if the eye is not centered and you can use a traction suture to rotate.

Okay. So, measuring is very important, okay. And, so in this film, I’m going to show how to measure the cornea and mark it for your suturing. And this is a technique where you first, you measure the horizontal diameter of the cornea. Let’s say it’s 12. You go half of that on the calipers and then you mark the central aspect of the cornea. And then you measure the vertical diameter and do the same thing. And you want to kind of get that geometric center the cornea and then mark it with a sinskey hook that you painted with a marker.

And that’s basically where you’re going to aim the trephine because remember the trephine has a target on it. Now, here you’re getting a trephine smaller than what you’re going to trephine the cornea with, like so you pick a 7, if you have a 7.5. And then you’re going to center that and kind of indented on the epithelium and then use a marking pen and mark a circle. This is just to help you center. And as you get better, you don’t have to do this. It allows you to see all the dots that are encompassed. Now this is an RK marker and that also helps to be able to place the suture.

So, let’s walk through this this frozen image again. I’m going to go back right there. All right. Now, here’s the thing. You got the central mark of the cornea. That’s where you’re going to aim your trephine. You have these RK markers where you’re going to help pass the suitors especially the cardinal ones. It’s not written in stone that the suture has to go through this mark but it helps, okay. Now, this additional trephination or epithelial marking, this is not necessary but what you’re going to do is when you put your trephine on the eye to do the actual transformation, if you can visualize all of these dots inside of your trephine, you know you’re centered pretty dang well. You know what I mean, because it’s encompassing the smaller diameter trephine. So, again this is the marking like bootstraps and, excuse me, suspenders and belt technique where you have a lot of marks, okay.

So, when you do the corneal host trephination, it takes two people. So, the tag or your assistant’s going to mend the trephine. This is a vacuum trephine. And you center it over that mark that you made in the center of the cornea. Then they get suction and then you can move it around a little bit and kind of make sure that all those dots are incorporated. Then you rotates fast until you get to the epithelium and then you do quarter turns which do about 70 microns each. And I don’t really like to enter the interior chamber. I like to go all the way, you know, maybe four or 500 microns because I can enter in the same place every time. So, then I lift up and I use a 15 degree blade and I make a little slash and then I feel the anterior chamber of viscoelastic. Generally, we use a cohesive viscoelastic and penetrating Keratoplasty because that means we can get it all out at the end of the case.

And then you’re using this curved corneal sclerosis in the group that you had already made. Now, the critical thing with this step is that the inferior aspect of the scissors has a longer, has a longer jaw and you can visualize it, so that you don’t cut the Iris. So, you visualize it and then you lift a little bit, so that you’re not going to cut the iris. You go all the way around until it’s uncomfortable with your hand and then you’re going to go back the other way. So, again you see the jaws of the scissors. You want that, you have to visualize it and they have to be perpendicular, so that you don’t get edge like that. So, I didn’t make it so perpendicular in that area.

Now, I’m going back the other way with the other direction. Your left hand is holding the graft and it’s kind of widening, peeling back, widening that little gap, so that you can visualize. There’s some hem here, so my assistant in this case would been able to maybe remove that hem a little bit and you’re going to just go all the way around. Once you’ve removed it, you can trim any kind of excess ridge with Savannah scissors, so that you have a nice vertical cut on the eye like that, okay. Alrighty.

So, question from Dr. Mogus Saschomi again. How many rotations do you do while trephining, not to make premature on plan? Now, to be fair you could do trephination into the AC. There’s nothing wrong with that. You just have to be quick with your assistant that they come off the suction. And but makes a nice cut all the way down. So, that’s okay to do. But if it’s, you know, you get an idea that cornea is probably in the periphery where you’re cutting is probably on 700 microns. So, if you want to go down 500, once you’re at the epithelium, you could probably do about 8 to 10 quarter turns. You just have to be looking all the time for any fluid coming out and then you would stop at that point.

And then, I got another question by Dr. Zarwan. You said Yamane intrascleral fixation, it can be done open sky? No, it cannot be done open sky. That would be a staged procedure. And for your Yamane, you have to have good visualization. So, this would be depending on how bad that the steering, depending on how bad the view was, it could be done prior to the, it could be done prior to the PK or even after, it could be done even after. Like I said, most of the time, when you’re doing an oil exchange, it’s because of endothelial decompensating. And they’re generally going to be having EK’s instead of PK’s.

Dr. Aravind Roy asked, what should you do if you have cut the iris inadvertently. Normally, when you cut the iris, it’s cut during trephination or with the scissors. Well, the best thing to stop bleeding is air, okay? So, what I would do is I would, you know, take a deep breath and calm down. I fill the chamber with viscoelastic and then I’d suture the donor on. And with four cardinal sutures, and then I put air in the AC until it stopped bleeding, okay. I would not try to get a retina catering go in there and try to cauterize it. I would just do the best that you could at that point.

Dr. Andre Walhany [Phonetics] asks what your choice cataract surgery with PK one step or two steps. We kind of covered that before but if it’s a mild to moderate cataract, I like to do the PK first if it’s severe, I like to do with the PK. Dr. Shiva Sethshivas Ancora [Phonetics] asks difference between DSEK and DMEK, that’s more of a, for the endothelial keratoplasty lecture. They’re both endothelial keratoplasty, one is just decimate membrane and one is decimates membrane with about 100 microns approach to your stroma.

Dr. Monniera asks how to avoid damaging the iris in case of inherently coma. Well, then in a case like that, I would make sure that you didn’t enter the anterior chamber with the trephination. Also prior to, prior to the trephination, you could make a peripheral paracentesis and fill the AC with viscoelastic to deepen it the most possible. Dr. Zarwan asks, how to avoid cutting the iris if there’s anterior sneaky eye. You may have to cut the iris, sometimes it’s inherent to the back of the recipient and you have to cut it. So, you just try to do it as carefully as possible.

Dr. Zahira Asthana asks what’s extra steps do you take in perforated corneas prior to trepanation? That’s a good, that’s a great question. You can still do vacuum trephination on a perforated cornea, it’ll still stick. What I’d like to do is inject a viscoelastic through the perforation. And in that case, I’d probably use a dispersive viscoelastic, there wasn’t going to expel so much, that creates room and it stays put during the, during the, during the trephination. I wouldn’t try to suture it or anything like that. So, just dip in the chamber with a dispersive viscoelastic. And you can still do, you can still do the, you can still do the vacuum trephine.

Okay, we’re going to move to donor prep, okay? So, I have a vacuum trephine here, but I don’t use the vacuum. I do put a marker and I marked that purple ring, because it helps to center better, especially if they have arches, okay. And now I’m moving the UVA out of the way. And I want to be able to see that whole purple ring there okay, that means I’m centered and I’m not going to do an eccentric cut. So now, I can see the whole ring. You can see arches right here on this side.

And then I don’t, I’m under the microscope here. And then I’m going to put the punch, you can see it’s an 875. So, this is a larger graph for whatever reason. And you do a firm punch, you got to use your muscles. And then I spend the sclera. And that makes sure that there’s no adhesions, and then I take it off, nice cut, looks good. And then I put a little optisol in there because of course you do this before you do trephination of the recipient. And then we’re done there.

So, I like to cut it under the scope. Most countries they, I’ve been to, they don’t do it under this scope, but I think you can center it better under the scope. Now, I use some a temporary KPro. Why on earth would you ever do this? Well, sometimes you do a combined case with retina and they got to do some retina work and you have to give them a view. So, you can do this plastic sutured in temporary KPro for them to do, to do the retina work. It just needs to be, they come in 8.25, but don’t do an 8.25 trephination, you need to do bigger because it doesn’t fit nicely, like 85, 87.5 in these cases.

Okay, open sky cataract surgery. This is fun. This is a video from Shenyang, China from a couple years ago. So, we’ve taken the cornea off, it’s under General anesthesia, we use a Weck-cel to remove aqueous, and then we’re going to try pan blue stain it, that’s going to help even though you’re not doing a CCC, not a continuous curvilinear capsulorhexis, it still helps to visualize, so. I like to do a Can opener style, capsulotomy in these cases. I used to try to Phaco, I used to try to do a CCC, but it’s more work than it’s worth. And it takes time. So, I’m just doing a Can opener style, capsulotomy like you would if you just doing old school, extra cap cataract surgery or six.

And you just go around all the way, you can see I’m finishing up here and going around, you want to make sure there’s no tags, and you want to make sure it’s a free cap that you’ve generated there. And then getting the lens out is very easy, it already wants to come out because of the eyes open. So, I’m making sure all my cuts are good. And then all you have to do is kind of, kind of edge one of the poles of the lens up, you can push on the square or you can just kind of rock it back a little bit, and it starts to want to come up.

All right, and then once you kind of get it over the edge of the iris in one quadrant like that, then you just go back and you’re going to spin it out. You can see how big this, this guy was. Look at that. I’d like to Phaco that after PK, no way. So anyway, that thing’s gone. Now, if there’s cortex, there’s not in this case, you need to use Weck-cel. First, you blow water on them, then you can use soft Weck-cel to remove the central aspect.

And then here I’m inserting a three-piece eye lobe, and so I put some viscoelastic. This is tricky. No doubt about it because they’re supposed to your pressure, there’s not a deep bag. This is the move right here you have to – you have to have the haptic and you got to use your other hand to push posteriorly and you got to tuck that into the iris and then release. So, it’s a, it’s a pronation out of your hand, torque in the haptic a little bit, pushing posteriorly and then releasing so that it flies underneath. And now, here we’re putting the cornea on.

All right, so that’s a, I’m going to go back there. That’s a tricky, it’s a tricky business. But as you can see, in a dense cataract like that, it’s, it’s a good thing, so. We’re going to move along here. Now, donor cornea suturing. So, this is that same case. Before I show you any of the video, look up here on the left, this is what you want your sutures to look like A, not B and not full thickness C. And then that’s how you want to hold the needle. It’s about three quarters up at the tip of the needle drivers.

So, we’re putting the cornea on right there. And it’s nice and situated. We have the marks from the RK, and then you use these special forceps okay that have double arms to help pass that first one. You want a 90% cut, and then you go back to your colibri forceps and you pass. And what you want to see is indentation and an arrow shape through the stroma that tells you you’re at the right level, if you don’t see any your full thickness, and if you see too much, you’re too anterior.

And then notice how I pull that, that needle through. I didn’t just yank it and one thing that distorts the, that, that’ll bend the needle or it will double the tip, you have to kind of bring it out gingerly. And then you do a 311 surgeon’s knot and you always lock it back onto the cornea. Okay, so that was three and then one, one. So, while we’re watching this suturing, Dr. IE Chan asks, how do you insert IOL in a triple procedure? Oh, hold on, I’ll get to that.

This is the most critical suture, you want to hold the cornea, see a central fold and see that it’s equally distributed on either side. Okay, so there we go. I like that crease, then I pass that needle. And then using your left hand to judge, you want to look at the gaps on each side here and make sure they’re the same. Notice I don’t go right to my mark, because when I when I when I look at it, it’s more evenly distributed if I go slightly to the left of my mark, oh shoot, I go back there.

So, we go right back. I’m going to go on the left side right there, okay. So, this is the most critical suture. This determines that, this determines how you’re going to, how well positioned that graph is going to be. So, Dr. Chan asks, how do you insert IOL in a triple, if posterior pressure is building up. It’s really hard. So, you got to manage the posterior pressure, you have to loosen, you have to loosen the speculum. You have to maybe use another suture on the finger ring to lift up the eye, and that will cause less posterior pressure.

This is going back to the suturing. This is a forehand suture. And you want to make sure that the graft is in the correct orientation there as well. And look how I use the calibers to help push that needle through the posterior corner. You could see that arrow I’m talking about as the tissue was flexed. This is the trickiest one because you’re passing backhand and you want to make sure it’s still a 90% pass, you grab the recipient and you’re going to see me make that little, that little distortion of the tissue, that little arrow that you see. And then you’re going to come through and then look, I’ll nudge it through like this. All right, and then I fill the anterior chamber with viscoelastic. So, the eyes nice and full and now, you can breathe because the graft is on, everything’s good.

And then the AC is filled with viscoelastic and then I wash them with a viscoelastic off the anterior chamber, and then I dry it and then you want to see this, you want to see that, that diamond, that diamond shape is very helpful to know that you got the sutures in. It couldn’t be better honestly, that one wasn’t the most beautiful diamond.

Dr. Arya asks how to remove the cortical matter in open sky, please give us tips. I would not do INA okay, the number one. What do you do is use squared some BSS and it’s going to cause the cortex to get a little fluffier and you use a soft Weck-cel and you just gently remove it from the center axis. You can leave the peripheral stuff. Just get it from the center axis. You can’t do the Simcoe. That is another option, Simcoe is another option.

Dr. Pradhan asked tips to avoid explosive hemorrhage in open sky. We’ll get to explosive hemorrhage later. Dr. Fekadu asks, what do you do if the donor cornea is actually dropped, dropped on the floor? I would still use it, especially if you didn’t have another one. If you have another one, use another one. But if you dropped on the floor, just put it back in the, in the solution, rinse it, and then you could use it.

Dr. Kabiru Lavorandobaalei [Phonetics] asks, doctor, what can you say about post-operative refraction? We’ll get to that. And then Dr. Zarwan asks again, did you recommend putting a bandage contact lens? Eh, I don’t do that normally. But that’s more for my electron postop, if I’m doing like an amniotic membrane at the same time, because I know they’re going to have a hard time healing, then I would put a bandage contact lens, but generally I don’t. I reserved that for the one week visit if they’re not healing.

After putting in, Dr. Manyara asks, after putting in six or eight sutures, can we give IOL if there’s raised vitreous pressure? I’m not sure I understand that type of again, ask what, I don’t understand a question. Okay, we’re kind of running low on time, I probably have another 20 minutes. So, here’s another, the finishing up of the sutures. So, we got the four cardinal sutures in. This case was done in Myanmar on the Orbis Flying Eye hospital, and look at that nice diamond, so that’s good.

And so now I’m going to do 12 sutures, right, so I have four of them in, I’m going to do eight more. So, it’s going to be two in between each of these sutures, or you could do 16 interruptive, is what you want. But you can see here, I’m not tying them after each place. This is the critical, that’s why I’m showing. You can, since the cornea is stable with those four tracks, four cardinal sutures, now you can pass sutures and just cut them, you don’t have to tie them. So, your assistant, you end up with a little bit of some spaghetti on the cornea. So, this is 20 times speeds, so he takes longer.

And then when you have to get a new suture as the assistant is giving you the loading the new suture, then you pass and tie. So, we’re going to end up getting 12 sutures here. So, two more in between each of those, and then we’re going to tie them all, locked down. Everybody asked how tight you want to tie them, moderate pressure, and you want to lock them all to the middle. You want to be able to see an indention you want to be able to see a crease.

Now, I’m taking the viscoelastic out. Okay, so I’m injecting fluid at the interface all the way around, and you’ll see a little expulsion of the viscoelastic when I do that. That’s critical because you can’t leave viscoelastic. Now, I’m going to do my running suture. This is an anti-torque suture. And it’s going to go in between all of these, but I do it either with an air bubble or BSS in the anterior chamber, not with viscoelastic. I want the eye like normal pressure, I don’t want it soft because I want this suture to not be as tight as the, as the other one.

So, once I’ve tied a knot, I go around and I take any slack out of the system. Okay, and then I tie it, I cut it and then I bury it. You’ll see firming up the, I bury the suture, and we’ll go back to that right here. So, that was really fast, I know. But the bottom line is, the running suture goes here. It’s anti torque, meaning it’s not radial sutures. The knot is buried here. And before you tie the knot, you tie the knot and it’s on the outside, you go around and you take any slack out of the system, okay.

You do that three times. And then you finish the knot up with a one and a one. And then you can put a little viscoelastic here and you have to bury that knot. So, what you do is you get a little more slack and then you pull from here and it’ll tuck the knot. And you can break it. It’s no fun if you break it you got to start over. But, but anyway, that’s what it should look like at the end of the case.

Dr. Panagiotis George Gordius asks, preferred time to Trephine donor tissue before host or after? Before always, always before, an ideal distance of suture entry at donor site. You want to be, I would say equal on these you want to be between one to two, by two millimeters, maybe one and a half to two millimeters on each side. Dr. Murtaza Mortazavifard ask, do you do PI for PKP? You know, I don’t do one, but they used to do it a lot. There’s not a problem to do it. It can help prevent that [indiscernible] [00:52:14] syndrome which is rare but can happen. So, I have no problem doing a Peripheral Iridectomy for PKP.

And then Dr. Parvez, Mohammed Parvez asked, what’s the lowest age for a donor? That I don’t use infant tissue on PK’s because it’s too soft, so I would say that teenage years, okay. You can use an infant for a DSEK. But you can’t use infant tissue for a PK’s. So for me, it would be like 15 years old and up to 65 for a PK. And then, how do you size the base, Dr. Anna Entandis [Phonetics] says how do you size donor based on recipient corneal size. So like I said, if it’s a 12 millimeter horizontal diameter, you can go with an eight millimeter graft. If it’s an 11 millimeter cornea, you want to go with like 7.5 or 7.

Okay, so we’ll talk a little bit about complications and we’ll be done. So, bad things can happen, right, in life and in cornea transplants. So, we’ll start with scleral perforation. This would be during the retrobulbar graft, okay? And so, anesthesia is your friend, you want to make sure that you’re doing the appropriate anesthesia that the patient’s good to do retrobulbar. And you have to have experience doing it. If there are these issues like, the body habitus, this is an American patient, obviously, we have a little bigger bellies in this part of the world. You know, he has to prop up this much, he’s going to have a lot of posterior pressure, so you may want to do general anesthesia for him.

So, the other time you can perforate the sclera is doing that flow ringer ring. So, look right here, these different types of, of needles, you don’t want to use a cutting needle, you want to use a spatulated or a tapered needle that’s C and D, okay. You want to do the upper scroll past and you want to rotate the eye for comfort, for your comfort, not the patient’s comfort. So, don’t try to pass in a very awkward manner, you can rotate the eye, especially once the ring is attached, and you’re doing subsequent passes, get it in the orientation that’s comfortable for you, okay?

How to avoid improper trephination? Like this picture, you can only, you can only cut your hair, you know, one time. Once you’ve cut it, you can grow it back, or you can’t, it takes time. So, once the donor is cut, it’s too late. So, the first thing you want to do is confirm the trephine size with your assistant and the nurse several times to make sure you’re on the same page. You always cut the donor first, if the donor is too small, you’re going to get hyperopia, glaucoma and wound leak. And if it’s too big, you’re going to have it’s going to look ugly, there’s going to be myopia steep case and exposure. So again, confirm the trephine sizes, the donor is 0.25 more than the recipient, and you’ll always cut the donor first, because if there’s a problem, you can avoid the case.

Materials for trephination, I like to use the vacuum trephines. You don’t always have these in other countries, but they’re more available now. And they’re way better. So, if you don’t have them, get them. I do 0.25 bigger. And then, how do you avoid misalignment? Remember, you want to see that little diamond, that’s the trick. You want to mark it, you want to center it and you want to have the same suture technique and tension all the way around. So, like I said, 1.5 millimeters on either side to two.

And you want to have the same tension which is moderate tension, but it’s enough that you can cinch down the knot, okay? You want to see like an indention a fold in the cornea. So, some questions about suture centering these were sent, these were sent before, we get back to that slide. Okay, where did I go? Okay, so, Dr. Arya asked beforehand, is it advisable to do an AC wash to remove the viscoelastic and form the AC at the end of surgery? Yes, like you saw before I do the running suture, I, I get the, I get the viscoelastic out of the eye.

Dr. Assad from Lebanon, what’s the most difficult step to learn in master? Passing the suture backhand is difficult, and passing those Cardinal sutures is difficult. So, that’s what you want to practice in the Weck lab. Also cutting the cornea squeal ram all those you can practice ahead of time in the Weck lab. So, you shouldn’t be surprised the first time that you do it. So again, backhand suturing and cutting the cornea recipient often the hardest. So, you got to practice that in the Weck lab.

Dr. Zarwan again, how to make the correct sizing? We’ve covered it if it’s a 12 millimeter. I mean, first of all, you got to encompass all the badness. So, if here’s a big scar, you want to get the majority of the scar. If it’s peripheral, you have to encompass it in your graft. But saying all things equal, if the cornea graft is 12, the cornea donor, excuse me, recipient is 12-millimeter horizontal diameter, you want to do like an eight millimeter graft.

And then, how do you treat positive pressure in surgery? That’s a really tough thing. What you do is you need to use general anesthesia if there’s a risk of it, you need to loosen the speculum that also helps. You can elevate the Flieringa ring by tying it to a some, like by, by using mosquito forceps or clamps and kind of elevating the eye a little bit that creates some that creates some depth. So, those are all things that we can do.

And then there were some questions about suturing techniques, so. Dr. Tarky [Phonetics] been call from Saudi asked the difference between torque and anti-torque. So, torque is if they’re radial sutures like this. Once you tighten them, the graft shifts a little. An anti-torque is like you saw in my video that’s going to, the sutures are passed obliquely, so when you tighten it, they don’t, they don’t rotate. And then Dr. Rahman from Bangladesh, how long before moving sutures? We talked about that. We do it about four to six months afterwards.

Dr. Poole Verity from Italy asked about the management of post-operative cell. We talked about that. We remove them based on typography. And Dr. Hurtado from Ecuador asked recommendations for better graft centering. I like to make the central mark based on the geometric center of the cornea. And then I like to use another trephine that smaller inside the area that you’re going to, trephine so you can see all the dots.

Okay, we’ve covered that. And then how to treat bleeding and a vascularized cornea, it may not be possible to avoid. You can put preoperative brimonidine or neo synephrine. That’s helpful. You do a 360 Peritomy and can do cataract prior to the trephination. That’s another option. How do you avoid damage to the iris? Oh, you got to be gentle. You want, the trephination you don’t want to enter the anterior chamber aggressively. It the first sign of any aqueous you, you pull off the trephine. You can damage the iris removing an AC, well, you need to cut out an AC and you can’t pull it out or you’ll get eroded dialysis.

Again, breaking any PAS, you want to cut and not pull pupil, remembering again cut, and then if you need to repair the iris we use Prolene sutures, either mattress or single bite. And then avoiding trauma to the lens? It’s difficult to damage the lens during trephination, but let’s see and I’m going to take out the cataract preoperative pilocarpine on all your graft patients is good, that way the cornea the, the pupil small.

And to avoid capsular rupture, it can happen and it’s not the end of the world. You want to make that you want to be efficient during the open sky ECCE. I like the Can opener style, and then I like a rigid lens in the sulcus. It’s Simcoe versus Weck in terms of cortex removal. If you do get capsular rupture, vitreous doesn’t behave the same way in open sky technique as it doesn’t Phaco. It doesn’t kind of keep prolapsing it, you just do a vitrectomy the best you can and you put a rigid lens in the sulcus, you can use some catalogue to help stain but it is somehow it’s more manageable to decrease in this scenario than with Phaco. And Phaco, it seems to want to keep coming. But I also want to do a PI for sure in a situation like this.

It’s 9 o’clock I’m going to keep talking I can talk for another 10, 15 minutes. Okay, so I hope that’s okay with everybody. Questions about glaucoma, and this is just kind of popped, and these had been populated prior to the talk. Can we do anything operative measures such as pupiloplasty to prevent post op glaucoma, or if they have glaucoma before surgery, you want to take care of that first and get it under control.

And iridotomy is not the end of the world. It’s okay to do, especially if there’s a shallow anterior chamber or any other reason why you may think they may have problems, that will prevent acute post operative pressure spike. But, you know, sizing the graft right and not making it too small is helpful because sometimes that’ll stretch the ankle too much but there’s a 30% incidence of glaucoma after penetrating keratoplasty. So, that’s going to happen, kind of regardless of what we do in some situations.

Dr. Novita from Indonesia asked how to prevent secondary glaucoma during penetrating keratoplasty. That’s like I said, you know, you size it right, you’re gentle, but still, it can happen. So, it can happen, that’s why you have to see patients even if they’re not having problems because you have to be able to measure the pressure et cetera. Now, management of glaucoma after transplant is more in my post-operative talk, so we’ll skip that.

Suprachoroidal Hemorrhage. This is bad. It’s irreversible vision loss. But there’s also the hemorrhage and then there’s pressure that can be different, and pressure can be managed but hemorrhage is bad. So, anybody who has a history of, you know, previous suprachoroidal hemorrhage, if they have a history of ocular trauma, this is the thing if they’re old, it’s going to happen. And if they’re in anticoagulants, it’s going to happen. So be more, I guess be more reticent about doing a local block on those patients rather than, rather than general anesthesia.

And how about in during the surgery, what increases the risk? Well, vitreous loss, sudden ocular decompression, like when you do the trephination or pain so like the patients, you’re hurting the patient, they don’t have complete anesthesia, then they start squeezing. And like I said, elevated intraoperative pulse rate valsalva. We don’t want them to be bucking right, the bucking means like valsalva. So, here’s a video of surgery, where was I was trying to trim some of the, the cornea there because there’s like a rim.

And then I start kind of dilating the pupil a little bit and the patient starts to get in a lot of pain, okay, that’s not me moving, it’s the patient moving. And then eventually, they move so much that there’s they start to get pushed to your pressure, okay? So, that’s not a suprachoroidal hemorrhage. That’s just post to your pressure. So, how do you manage it? You got to put the cornea on and you got to calm the patient down, you can even put your thumb over that area, okay, like this, until they’re calm. And then you suture it in and they can still be okay. In that situation, what you can do is you can remove the IOL, like let them expose the IOL, just put it, close it on that close the cornea down, and then you can go back later and put in an IOL. So, don’t be, don’t be scared if they expose an IOL because you can manage that. It’s blood, the suprachoroidal hemorrhage that’s bad.

Okay, so, there’s this thing called a Cobo keratoprosthesis that you can have available, if they start to expose, it works, okay, still is stuff comes around outside. But that little metal thing allows fluid to be infused to help keep things at bay. The main thing is to calm the patient down. That’s what your anesthesiologist is going to do. And then you’re going to, you got to put that cornea on. So, it’s not easy, and your blood pressure is up and you’re shaken and, but you can do it.

Okay, so I think we’re, I think we’re pretty much done. I’ll answer the questions that you guys have submitted. We’re going to go over the poll questions again. So, we can skip this one because we talked about that one, but Lauren’s not a contraindication, which of these is not a contraindication. We talked about contraindication. So, everybody should get this right or else you get a. Okay. Let’s see. Answer survey says. All right, 94%. Okay, you other guys were asleep, I guess for the first part.

Which one of these is true? The donor should be bigger or the recipient should be bigger? Again, we should get 100% on this, folks. Survey says, yep, almost. Okay. And then lastly, corneal scar and a mile cataract should do a triple. You should do the cornea first, you should do the cataract first or you should do endothelial keratoplasty? All right. Yeah. You guys are good, 92%. All right. A few questions more and then I’ll answer some that have been posted.

So, this was Dr. Fekadu from Ethiopia, a 22 year old patient with traumatic central corneal abscess, what is the place of therapeutic PKP? Okay, so you can do, that’s what they need PKP because they probably have a fungal also. But if you don’t have tissue, this thought you can do a conch flat. So, I’ve been to Peru several times. And one of the hospitals I visit in Peru, they don’t always have tissue, they sometimes have tissue. And when they don’t have tissue, they do a conch flat, at least until they can get tissue. So, this brings a blood supply to help kill the bugs. It’s better than nothing. It isn’t ideal. It’s better to do a therapeutic PK, but it’s better than nothing.

Now, a lot of questions were about COVID. So from the EBAA Association of America, so far, there’s been no report cases of SARS through, through ocular tissue. They do a double iodine prep that helps for any kind of Coronavirus if it were on the surface but anybody who tests positive for COVID they are not allowed to donate their corneas, okay, so that’s number one, but that’s if they’re in the hospital, right? They’re not, we’re not currently testing all patients for COVID who donate their corneas.

But if they know they have COVID, and then they die, we’re not using those corneas. And it’s kind of a fluid situation. I don’t know if they’re going to end up testing everybody for, but currently, not all donors are being screened for COVID in the US. So, thank you, and I’m just going to answer a few more of your questions here that we got. So, and there are a lot of questions. Okay, so. So Dr. Justin Prashanth asks, can keratoconus, do you still prefer a donor cornea, 0.25 larger? Yeah, I do. I don’t like 0.5. I mean, but some surgeons do. It’s a choice, you have to do it. And then you kind of see which works better for you.

Patrick Odda from the Ivory Coast, Ivory Coast, excuse me, ask how to prevent and manage resilia syndrome. Well, to prevent it, make sure you don’t leave viscoelastic in the eye. A PI will prevent it. And if you get it, there’s nothing you can do about it. You can manage the pressure post op but if the pupils blown, it’s going to stay blown. You can like, couple months afterwards go and suture and if it bothers the patient, but generally speaking, there’s not much you do about it.

Dr. Julia Wudiati [Phonetics] asks, during your penetrating keratoplasty what percentage of your success, what is percentage of your success rate on all your patients? Probably 80%, something like that. I think that’s pretty good, 20% are going to fail. Dr. Wasilla Sewol [Phonetics] asks, what about the diameter of KP, a PK in DMP. I’m not sure what DMP is. So, Dr. Sewol, if you want to tell me what DMP is, and I’ll answer that.

Dr. Taro Rashid asks, my ask what is the chances with HIV positive cases with corneal abscess ending in scar will benefit from PK? Well, that’s a specific case, I got to say, I don’t think I’ve ever had a HIV positive patient with a corneal ulcer that needed a PK but, you know, in the US nowadays, HIV is a manageable disease. So, they would do just like everybody, I don’t think they would be any less successful.

Marginal, marginal, okay, Dr. Sewol, marginal degeneration. Pellucid, this is a very difficult, it’s very character, Globus and pellucid are the hardest situations to do PK, because suturing in the periphery, you need to encompass the area, that’s weak. So, sometimes it takes two grafts, like one eccentrically place, and then coming back and doing a central one, you have to do a large diameter graft, a lot of times it’s off center, not the ideal situation. But that’s the story with that. I have a tyrian’s case, doc can sometimes work better in these cases, but it’s not an easy situation.

Dr. Rachet Alon asks, in PBK, with ACI well, what will be your plan of management. So, if it’s a PBK, I would take the ACL out and I would do with your money. And then I come back and do DMEK, or DSEK. Now, if the PBK was terrible, then I would probably just do a PK and leave the ACL in place, if there was deep enough versus, I will exchange so it’s tricky. It’s tricky. Dr. Erica Cleans asks, is there an ideal patient to select for initial PK learning phase? Also, obviously, the more time spent in one lab prep, the better, but do you have recommendations for a minimum prep time before attempting PKP?

So, you should be able to, before you do your first PK, you should be able to do good cataract surgery whether small incision, extra copper Phaco, you have to have the hands right, your brain has to know to look under the scope. You don’t do a PK before you do Phaco or extra cat. The best patient would be an older patient with PBK or kind of a low potential not like a young keratoconus patient, you want somebody who’s kind of older maybe has glaucoma, maybe the visual potential isn’t that great. And I would do it under general anesthesia as well on your first one.

And then you want somebody to scrub in who’s done it before so they can help you. Once you’re in there and you’re doing it and it’s not that hard, because not that hard. As long as you know how to suture and you practiced in the Weck lab before. The live surgery is not that bad, okay. Sorry, I think I’m going to text it for my office. No, I’m not. I’m still good. So, I hope I answered that question. Dr. Ajay Kumar Paul asks, what age can PKP be performing children? I don’t like doing PK’s in children.

If they have an ulcer in their teens, I let them live with the scar until they’re 20, 22 before I do a graft, because they don’t take care of them. Now, many of you may be pediatric ophthalmologist. I don’t do pediatric keratoplasty. Obviously, their situations and which it’s required, but they just generally don’t do well. It needs to be managed, it needs to be managed to the medical school because they need a cornea specialist, glaucoma specialist and pediatric ophthalmologist to follow them. So, I’m in private practice. It’s pretty rare that kids need grafts thankfully but if we’re talking teenagers, I don’t like teenagers, we do it in their 20s. If you’re talking to young kids that needed because it’s their only eye, it can be done if it’s needed, you know, if PK can be done if it’s required.

Let’s see if I got everything here. Okay. Well, Dr. Anonymous, when the keratoconus is inferior, can the trepanation be decentered? Yes, but better to have a larger graft, and then a disinterred trepanation. Another anonymous attendee, is it necessary to remove all sutures? No. I mean, if you can remove them and you get a good shape, leave the rest. Dr. Docky Sherpa asks which is better interrupted or continuous. I like a combination because you can remove the sutures earlier. Also, if you just do interrupted sutures, it doesn’t look pretty. So, somebody’s going to see your graft and they’re going to say, man, I could do that, why did I send them to a cornea specialist, okay.

I’m saying that in joking way, but I continuous it’s, it looks better. And so, a combination of the both not just looks pretty but it’s safer, you can leave the continuous in forever, which is going to keep them from rubbing the eye and perforating it. But I like a combination of both, but really, it’s what you’re comfortable with. All right. I think that’s it. So, I’m going to sign off now. These, there’s a few more questions, but it’s around 9:15, so I have to go to clinic. Thank you for your attention. And we will do this again. Thank you very much.

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June 29, 2020

Last Updated: October 31, 2022

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