Surgery: Baerveldt Implant in Congenital Glaucoma

9-year-old boy with congenital glaucoma. He lost vision in the right eye, secondary to advanced disease, so this is his better eye. He has had trabeculectomy and trabeculotomy done in the past, but the pressure is still high. We just measured his corneal diameter, and it’s 14.5 millimeters, so significant buphthalmos. You can see Haab’s striae there. So we just put a traction suture now. We are planning on starting Baerveldt’s shunt. He has a very large eye, so I think we’ll try to put a 3.50. But we’ll see how it goes. So I’m opening 5 to 6 millimeters from the limbus. And so I really want to get through the conj and the Tenon’s, all the way to sclera. I think it is more comfortable for the patient if the incision is 5 to 6 millimeters posterior to the limbus. It is also easier for you to have access as a surgeon to the muscles in the back, and to the limbus in the front, because the shunt goes — the plate goes in the back and the tube goes in the front. So you want to be kind of in the middle, so you have good access in both directions. So I’m just dissecting a little bit. I will put Xylocaine with epinephrine, epinephrine for hemostasis, and Xylocaine for comfort after the surgery, but also for dissection. It really helps with the dissection. Just to inject some anesthetic there. So I’m dissecting posteriorly. That’s where the plate is going to be. I’ll make the incision long enough so we can put the plate. And I’m always surprised that I’m able to fit the big device. So you want a bit of a curve on these scissors. And these have a bit of a curve. You want the blunt tips, because you’re going blindly in the back there. And really, you just want to make a nice space, where you put the shunt. So I will be pulling on the muscles now, and I always let the anesthetists know that I’ll be pulling on the muscles, just because they can develop — especially children can develop significant bradycardia. Make sure the anesthetist is watching the heart rate. So we’re going for the lateral rectus muscle now. So I’ve got the muscle now. I just feel that I have the muscle, because there is quite a bit of resistance there. And so I hook the muscle on the muscle hook, and I’m gonna slide it to the back, and again, I’m just making space behind the muscle, between the muscle and the globe, so there is room for the shunt plate to fit there. I’m going to go for the superior rectus now. And it is sometimes a little bit more difficult to find, but it is there. I feel it. And again, I have the muscle, and I’m going to slide the hook just in the back there, to make space between the muscle and the globe. And you just want to get to the Tenon’s-sclera interface, like so, and it’s really nice with these scissors with sharp tips to do that. Westcotts with sharp tips would be easier, because they have slightly bigger blades, and it’s kind of easier to dissect, but these work as well. So you want to be on bare sclera. You don’t want to have any Tenon’s left there. So this is the plate of the Baerveldt shunt. Quite large, as you can see. What we’re gonna do next is just cannulate the tube with some BSS, and then we’ll put a 7-0 vicryl around the tube to occlude it. And 7-0 vicryl usually dissolves, in most people, in 4 to 6 weeks, and at that time, the tube opens, and starts to function. Until then, the Baerveldt is closed. There is no filtration. And the pressure continues to be elevated. So I want to test to make sure that this is watertight. And it isn’t. See? See? The fluid is coming. So I’m gonna tie it again. So now it’s watertight. Nothing is coming through. So it’s good. Okay. So next we’re going to position this plate under the muscles. We’re gonna get the lateral rectus. Yeah, got it. And you have to hold on really tightly to the plate. And push it further than you think you need to go. And I’m gonna go for the superior rectus now. Confirm that the plate is under the muscles. That’s there. So it’s good. So we’re just where we want to be. Prolene is really good for this purpose, because you want a non-dissolvable permanent suture here, and prolene is better than a nylon for that. You’re gonna make a pass in this sclera. It’s kind of similar to what you would do in strabismus surgery. Sometimes I would turn the needle around to go through the hole in a Baerveldt shunt, but this time it just went really nicely, so I didn’t have to change anything. So the same on this side. Some surgeons attach only one inlet in Baerveldt. Just because it is, once again, sitting under the muscles. It’s a nice secure place for the plate. So here I go 3-1-1. And then I will cut the ends with a 75 blade. I will make it maybe a little bit longer than I thought I would want. Because it’s a child. So bevel up. And I will take the 75. So I will make a groove, but I will be more gentle and superficial with the groove in a buphthalmic eye, and I’ll make a paracentesis. I always make paracenteses before I enter the eye. So I always cauterize this groove. So I’m going to enter the anterior chamber now with a 23-gauge needle. This entry into the anterior chamber needs to be parallel to the iris. And you want to go as posterior as you can, but you really have to be careful that you don’t go into the iris, and sometimes it can be a little bit tricky. You may need to make more than one entry. So you see the needle in the anterior chamber. So now I’m going to push the tube into the anterior chamber, and sometimes it’s like pushing a wet noodle. One of the reasons why you want to have a nice bevel up is so it’s easier to enter. See, it’s showing up already in the anterior chamber. So that’s why you want paracentesis. You want to inflate the eye when you have to. So this 8-0 vicryl — really the function of it is just to hold the tube in place. So next I’ll take the Tutoplast, please. So this needs to go all the way to the limbus, under the conjunctiva. So I’m just going to attach this pericardium to the sclera, with the 8-0 vicryl suture. When you work with conjunctiva, in any glaucoma filtration surgery, you want to be as gentle on conjunctiva as you can, and use gentle forceps, but also gentle sutures. So if you noticed, I switched to an 8-0 vicryl on a — we call it BV needle. Blood vessel needle. And this needle just doesn’t have a cutting profile. It’s a very small tip. It’s a round tip. So that the holes that it leaves in conjunctiva are very small. And they don’t tear as much, and if there was filtration, like in a Baerveldt, there would be less risk of a leak through the needle hole. As far as postoperative regime, at the end of the surgery, we’ll place a drop of atropine, Vigamox, and prednisone, and postoperative regime will be Vigamox 4 times a day for one week, atropine twice a day for one week, and prednisone starting 6 times a day for one week, and then tapering by one drop every week. The reason I use atropine is to make the postoperative period more comfortable and relax the ciliary body. But also to hopefully prevent malignant glaucoma, aqueous misdirection. Especially in older patients, patients who have angle closure glaucoma. Not this situation, necessarily, but in elderly — older patients.