Surgery: Penetrating Keratoplasty

This video demonstrates a penetrating keratoplasty surgery in a 28-year-old patient with a history of infectious keratitis. Dr. Pineda performed the corneal transplantation and there was no need for cataract extraction as the lens was clear. He explained his suturing technique and also spoke about the postoperative medication and follow-up.

Surgery location: on-board the Orbis Flying Eye Hospital in Chittagong, Bangladesh
Surgeon: Dr. Roberto Pineda, Massachusetts Eye and Ear Infirmary, Harvard Medical School, USA


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Dr. Roberto Pineda: So, this is a 28 year old man who had a history of infectious keratitis, maybe one year ago. And we believe he perforated at that time. And this is the resulting scar, he has adherent Iris to the backside of the scar. So, we will do a full thickness penetrating transplant here we will assess the lens after we remove the cornea, and be prepared to remove the lens if needed.

So, we will go ahead and start by marking the optical center of the pupil, which will do with the caliper. it’s always important to determine the optical or geometric center of your cornea, even if you’re going to use an eccentric trephination. So, things can be a little deceiving, without this reference point.

So, we’re probably going to be using about a seven-millimeter trephine for this case. Remember, we’re removing a scar here. So probably part of the endothelium is quite healthy. So, we don’t want to remove the unhealthy epithelium. So, if we make this, essentially five millimeters, or five and a quarter, we can measure. So usually when I do this, I start with the limbus, identify the limbus, and then make a mark in the center. And same thing on the other side, limbus first and center and go ahead and do the same thing in the horizontal. That was pretty good.

After we establish our optical center, we are going to make our marks with the RK marker. These markers are not used for radial keratotomy anymore, but they make very useful for doing penetrating keratoplasty or DALK surgery, where you need to make a mark. Now you will notice that the magnification here is low. We do not need high magnification for this case, which is important. So you can see the radial marks here, I like to make a secondary mark just on the inside here. These are where I hopefully will be passing my sutures.

Now the next thing we are going to do is, we are actually going to prepare the donor tissue, the host punch is going to be seven millimeters. The donor punch with this is going to be seven and a quarter.

Now remember, we really just care about the optical center here, we don’t have to worry about these. you will see these peripheral blood vessels here; we can make the graft a little bit smaller. One of the risks of graft rejection is proximity to the Limbus. So, if we don’t need to be by the Limbus, we shouldn’t be by the Limbus. So, making the graft a little bit smaller is going to be helpful here.

Brimonidine is one of my favorite supplementary medications for any type of conjunctival or vascularized corneal procedure, so really it is extremely helpful. You can see the superior part of this cornea is quite clear, the inferior has some scarring and centrally, we’ll find out what’s going on.

We can go ahead and prepare the donor tissue. We’re going to put a little corneal shield on here while we’re waiting. So, this is a vacuum trephine. And we’re just going to center the tissue here. And we do that by just moving the tissue around and rotating the base of the device to make sure that it’s in good position. We will turn on the suction just to keep the graft from slipping. And this kind of turning technique of the trephine base is a very good way, of course the cornea is not perfectly round, it’s a little oval, and we can go ahead, and punch and we slowly lift off the top just to make sure, because sometimes the everything comes off.

And again, then we usually put a little bit of optisol here on the graft, so it doesn’t dry out. You don’t want to forget about it.

So the vacuum ttrephine works best when it’s wet. And what’s nice about the Brimonidine is it tightens the conjunctiva makes it much less likely to get sucked up into the vacuum trephine, which can be quite annoying sometimes.

What we do here is we line up to inter barrels. Once the two inter barrels are lined up with this particular model, we go back four to six quarter turn, so 1,2,3,4,5,6.

Each quarter turn is 50 to 75 microns., with this particular model, some go up to 100. And then what’s very important here as you’re applying the vacuum trephine is, you want to make sure that the cornea is perpendicular to your microscope. That way you can see down the barrel. So, I’m rotating the eyes so it’s lined up with the cornea.

And once it’s in place, we are going to press down a little bit. And we’re going to let go quickly.

We have suction, that’s great. Now we’re going to quickly rotate, 123456 That’s our 6.

I am going to wait a minute here; he is bellying a little bit I don’t want to manipulate the eye too much. Usually if their bellying, if we do try to have too much manipulation, we can have the iris prolapse and other things like that. Usually we use some viscoelastic, so we’ll put some Healon in.

Remember the patient is phakic, at this point, we don’t really know what the lens status is, so we’re going to take a little peek here.

And we’re going to take the scissors to the right and I’ll take Utrata to forceps. I’m going to use the Utarata forceps to peel the iris off, we have to be a little careful. If you kind of are a little aggressive in removing the iris tissue, you can rip off the iris.

So, what I like to do here, we can revert the tissue, we can see the edge of the graft and we can kind of try to pull it away.

Maybe try to preserve as much Iris tissue as possible. you want to be a little careful here but we are looking reasonably good.

Some BSS, please. I think the lens looks pretty clear.

Looks like the lens is pretty clear to me. You know I can get a good read reflex. You know if he was 65 I might consider taking the lens, but at 28 he still has accommodative ability. So I prefer to keep the lens if I think there’s a chance in young patients and I think we’re ready for the cornea.

This gets turned over on the surface, you can pick it up a different way, I like to kind of flip it over. So first thing I look at is I look at if there’s any Arcus and if there’s a large area of Arcus, I always try to rotate it superiorly to hide it under the lid.

I don’t really it’s pretty uniform here. There’s a little bit but I want to turn the graft a little bit this way for optimal setting and then we’re ready to start suturing.

Because of the vascularization for sure, there would only be interrupted sutures and in the non vascularized patient you could consider the use of a combination or running suture. Now we’re going to use those artful dots that I placed to help with placement of the tissue. And always the first few are a little tough because, it’s hard to get the tension hard to get the position correct.

Then sometimes again we do a 211 or 311, usually the first few sutures, I will do a 311.

And Dr. Panetta Do you like to do alternating so you put this place, stitch and then go away and do the counter stitch? Correct.

So again, these first four are usually the most challenging because you don’t really have a stable anterior chamber. Now that these first few are in, we are gonna go to a 211. You do have to tie it a little tighter for the first few.

Interrupted sutures, you know, they could be the standard for all your cases if you wanted it to be. But we use interrupted sutures here, because of the vascularization we have much greater ability to do selective suture removal in the post operative care. Running suture, unfortunately requires that you be able to keep the running suture in for three to six months. And that may not be possible with running suture in a vascularized cornea. So usually vascularization leads to lose their sutures, in the post operative period and higher chance of rejection.

And then Roberto, you mentioned something very interesting about with vascularized grafts, the use of Avastin or anti VEGF agents, what’s your experience? Or how do you do that? And so what determines Sometimes we give it ahead of time, before we do the surgery, like by two weeks, and other times, we will do it afterwards.

And I usually give it’s subconj at the Limbus, I used to do it right in the office at the slit lamp. It works very well in helping to control particularly in the post operative period, the kind of progression or worsening of vascularization in the post operative period because of the inflammation. And then do augment that, we use the steroids a little more frequently in the first week or so to reduce the inflammation as much as possible. But there has been some nice studies showing the infiltrate of leukocytes within hours after a graft, and those blood vessels bring in all those leukocytes, so having those under control is nice in the post operative period.

And then speaking of the post op period, can you tell us with this patient, what would be the post op meds and how often you’d see them in clinic? Typical evaluation, you see them at a post operative day one, usually, we start with antibiotic, could be many different types, but usually four times a day for the first week.

And then usually steroid drops, I personally like to use a times a day for the first week, and then go down either to six or four based on how the patient’s doing. The other important parts of the post operative management is the intraocular pressure. The high pressure is bad for the endothelial cells. So a lot of times these patients can have pressure spikes, we use a lot of viscoelastic. We might be doing synechiolysis, things that release pigment into the angle. So IOP spikes are common. I typically will give all my postop patients Diamox postoperatively to take to help reduce the IOP spike. And the second thing that’s very important is to manage the epithelial defect. So all the grafts most of them the epithelium sloughs off right away, they have 100% epithelial defect in many cases, and that needs to be managed. And my expectation is that by one week, the epithelium should be 50% healed at a minimum. If it’s not healed, 50% you have to do something to promote that, which might involve placing a contact lens, it might involve, a tarsorrhaphy if the patient has a neurotrophic cornea. So there are a lot of things that you need to do to manage that. So I essentially, if someone has a chronic epithelial defect, I see the patient every week until their epithelium is healed.

So just all I would say is when you’re doing the surgery here, you want to make sure you have a nice formed anterior chamber when you have your eight sutures in place. I typically like to bury these 8 sutures when I am done before proceeding to the next eight. I think it gives you a much better idea of the kind of wound symmetry and tightness and I replace any that I need to, before proceeding to the next eight.

So two quick questions about sutures. When would be the earliest you would remove one because of astigmatism. So this is of course a very good point. The basic rule with sutures is in the very beginning, meaning the first two months, you do not take out sutures unless they are loose. A loose suture is a liability for the patient. They are at risk for infection or enhancing inflammation leading to possible rejection. Six to eight weeks is the absolute earliest you would consider removing a suture unless it was loose or broken. And if it is loose, when do you remove it? So I remove it as soon as I see it. And if it’s even if it’s day one. If it’s very loose, I will remove it but it probably wouldt need to be replaced. So anything in the first week sometimes you have to bring the patient back to the operating room or to a minor procedure room, if the sutures are very loose.

3D Version

December 2, 2017

Last Updated: March 2, 2023

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