This video demonstrates a DSAEK surgery in a patient with Bullous Keratopathy. She also had a previous trabeculectomy surgery and the bleb is clearly seen. The incisions were carefully planned to take the bleb in to consideration. The descemet’s membrane was carefully scrapped off and was replaced with that of a donor cornea.
Surgeon: Dr. Mark Mannis, University of California Davis
Dr. Mannis: She’s a lady who has had a previous trabeculectomy, you can see the bleb, the small cystic bleb at the top of the field and she has Bullous Keratopathy. Our plan originally was to do a combined phacoemulsification DSAEK operation. However, the edema is so significant that we feel we cannot see the lens well enough to do the phaco and in fact at the slit lamp the lens appeared very clear. So we’re going to do a Phakic DSAEK. So, we modified the incision slightly because of the DSAEK surgery.
] I’m going to make a five-millimeter conjunctival flap temporally.
So we’ll make our shelved incision in the sclera using a crescent blade. When performing DSAEK the incisions are extremely important because at the end of the procedure if there is going to be retention of the air, everything needs to be very tightly closed. We spend a lot of time constructing incisions carefully in a case like this. Many surgeons use a clear corneal incision for DSAEK, I prefer the scleral flap simply because I think it adds security to the procedure.
We need two side ports to do DSAEK so that we can manipulate the graft once it’s in the eye. The complicating factor here is the presence of the bleb, so I need to avoid the bleb when making my incision. So initially we dilated the patient because our plan was to do a phaco.
But since we’re not doing a phaco, I’m going to put in miochol to bring the people down and protect the lens. As you can see the pupil is coming down very nicely. And now I’m going to put healon in the eye, we do not use a dispersive viscoelastic. We use a cohesive viscoelastic so that the viscoelastic doesn’t coat the back of the cornea and make it difficult for the graft to stick. You always have to be mindful of that trabeculectomy when doing anything. Now I like an 8 millimeter trephine.
So this is the outline of the spot at which we’re going to strip descemet’s membrane in a moment. And the graft will be placed inside these blue dots on the back of the endothelia.
So what I’m doing now is scarring the descemet’s membrane which will allow us to peel it off the back of the cornea. I don’t know if you can see in the camera but we are now pulling descemet’s membrane down. And there is the descemet’s membrane.
It’s important to unfold this to make sure that you have the entire thing, broken apart a little bit but it looks to me like we have all of the descemet’s membrane here.
So, this we will submit for a pathology. Ok, I will take the healon next please and then the scraper one more time. One of the important things to do is to roughen the periphery which helps with adherence of the graft. I think I see a small remnant of descemets that we left so we’ll go in with utrata forceps and see if we can retrieve that safely. Trying to take out all the viscoelastic that’s in there. Because of the edema, it’s a little bit hard to see so I’m actually going to take off some of the corneal epithelium which will make it easier for us to co-locate the craft. This will allow us to see much better. So, we’ve going to enlarge that incision that we made, to be sure that it is a full 5 millimeters, both internally and externally.
So now we have a sheets glide which we’ve put in, our lens is protected and now we’re ready to put the graft in the eye.
There is our donor cornea. Since I’m going to fold it I’m going to put a little healon, down the center just to protect the endothelium. We’re looking at the endothelial side.
So what I’m going to do now is simply separate the two layers and then I’m going to do a 60:40 fold. So, you can see now that the cornea is folded with an under fold of 40 percent and then over fold of 60 percent. What I have here now is just a 25-gauge needle. And as. Dr. Sam deepens the chamber I will push the graft into the eye. The graft is actually unfolded, it’s not quite unfolded but it’s unfolding as we put it in and we need to get the sheets glide out without pulling the graft out. So now the graft is in the eye partially unfolded.
We’re now going to close the wound and then we should be able to manipulate the graft into position. We will use a butterfly suture for this.
So now we have our scleral wound closed. Normally as this remained folded, we would now use the fluid to unfold it, it’s actually unfolded already.
So the graft is still not in position but it will be easier for me to pull it into position with air in the chamber.
So will put a little air in there. So I’m going to see if we can just pull the graft a little bit better into position.
I’m actually only touching the endothelium in one position. It’s not touching anything underneath, so it’s really quite safe.
We have a fairly firm eye now; the chamber is moderately deep. So, the graft is now in good position but we like to deepen the chamber.
That’s the lens you’re seeing through the pupil. These are small air bubbles between the cornea and the graft, that’s not of concern.
I’m going to try and put a little air in front of the iris using a 30-gauge needle. So, looks like we may have a little bleb leak. I can see air behind the iris right here.
[00:11:49] But I also have a little iridotomy, that’s why I think that the air will come forward, I don’t think we will have a problem.
OK so here’s the circumstance. We have a fairly firm eye, a little bit of air behind the iris and we have what looks like a small air leak from the bleb. The eye will decompress fairly rapidly. I think it’s highly unlikely this would eventuate in any sort of a block situation. My intuition would be to close the conjunctiva and to allow the eye to recalibrate. We know we’ve got some fluid between the iris and the donor, the donor is in good position. I think what we will plan to do is, close the conjunctiva, perhaps add a little bit of fluid to the anterior chamber and hope that the patient will deepen over the next 12 hours.
I might point out that we rarely do Phakic DSAEK. The history of phakic DSAEK is that, these patients do over time develop lens opacities and require cataract surgery. However, as you saw at the beginning the extent of corneal edema, although she doesn’t have any scarring in the cornea, would make it virtually impossible to do a phacoemulsification safely in this situation.
Actually, we’ve done a number of phacos underneath patients who have had previous DASEK, and you simply need to make your phaco incisions in such a way that there is plenty of room, so that you don’t come in contact with the graft, also using copious amounts of dispersive viscolastic.
It really isn’t a changed technique from your usual phaco, except be sure that you maintain a very deep chamber the entire time. Is there a risk to the graft? Yes of course. But if you take special precautions these patients do well. Now the tension in the eye is relatively normal. We have a very shallow but formed anterior chamber. I think there’s probably a leak in the bleb, I can see little bubbles in the bleb up here and there’s obviously some air under the conjunctiva here. But undertaking a bleb repair at this time is probably not appropriate. So, I think what we will do is, will dilate the eye, that will bring air forward to prevent any pupillary block, cover the eye copiously with the antibiotic ointment and patch the eye firmly. Hopefully by tomorrow morning, will have a deeper chamber than we have right now. In a normal case, what we would do once the graft is in position, we deepen the chamber, we wait for ten full minutes and then at the end of the 10 minutes we remove enough air so that we have a bubble about the size of the craft which usually makes it about an 80 percent air bubble. If you do that and then dilate the pupil the chances of getting a pupillary block become very small.