This video demonstrates Trabeculotomy surgery in a 4-year-old child with congenital glaucoma. Trabeculotomy is a technique that can be used to treat congenital glaucoma even when the cornea is cloudy, making it a valuable technique to master.
Surgeon: Dr. Daniel Neely, Indiana University
Dr. Neely: So we have a four year old with congenital glaucoma. No prior surgeries. And the vision and the right eye is hand motion. So we’re trabeculotomy. So the conjunctiva is being pulled up too much with that traction suture, I’m going to put the traction suture in the cornea. I sometimes don’t like the corneal traction sutures because they can pull out. They can also be problematic if they go too deep and you start to lose your chamber depth
Trabeculotomy has the advantage of being able to be performed in all glaucoma patients whereas goniotomy you can only do in an eye with a clear cornea. I think of those two procedures that they’re both essentially equally effective.
So we have a couple of options here you can do the trabeculotomy from the top at 12:00 or temporal, those are the most common positions. I’m choosing to go temporal so that this is the conjunctiva that will be disturbed. If the child needs another procedure such as trabeculectomy tube shunt we’ll still have normal conjunctiva superiorly to work with. We need about a 4 millimeter area here. Take the cautery.
Question: What is your preferred shape for a sclera flap?
Well first of all I don’t think it matters. I do a triangle because it’s just easy. But whether it’s… it doesn’t have to filter, right? I mean this is you’re not going to have filtering out of this like a trabeculectomy. It doesn’t matter. Right. All we need is access to Schlemm’s canal. If I do a trabeculectomy… Yeah I would I would still do a triangle. I really don’t find them to be terribly helpful in children. To form this triangular flap. There are lots of different blades you can use. Some people use a 75 blade at home I have guarded blade that’s a 300 Micron guarded blade and you just press it down and it won’t go more than 300 microns deep.
So I’m going to start it or try and get her a flap here. And I’m being rather careful because this eye has really been stretched out so I’m watching my depth as I do this. I’m aiming for a half depth. Of course that’s… you don’t want it to thin but you also don’t want this to be too thick. But again keep in mind this is a buphthalmic the guy the corneal diameter is 14 millimeters. So what might be normal depth in an adult is going to be less in this patient. Or actually it’s is going to be deeper. Because the sclera is just thinner, it’s been stretched out. What we want to get to is kind of the blue-white junction.
So some of the landmarks that we’re looking for here: Sometimes you’ll see little bleeding vessels. I think there’s one right… here at the tip of the spear. Those are typically little vessels draining Schlemm’s canal. There’s one right there. Those are draining from Schlemm’s canal. So I like to see those. Those tell us about where we want to be. The other… in this eye, since it’s so stretched out, it’s not a real super distinct blue-white junction and that’s probably… but it’s about right here. I’m going to go… I’m going to do about it 2-millimeter radial incision just anterior to where these little draining vessels are.
We’re essentially just going to go down real slow until we start to see some aqueous come through this.
A little fluid there.
Before I do anything with the trabeculotomy, I’m going to try and confirm… where we are with this 6-0 Prolene. I’m taking the traction off here, let me zoom out a little bit.
And you see how easy that advances. And we’re looking to make sure that it’s not in the anterior chamber. When we strum it here. I’ll take another piece of that 6-0. So I’m going to cannulate the other direction. So these are not only they’re confirming but they’ll stay there as markers. Because if you lose your anterior chamber depth, it’s very hard to then find Schlemm’s canal. So it’s a bit of a way to cheat and keep that place. And it should advance very easy, if it doesn’t advance easy, then you have to wonder why.
Now I’m going to change the lighting so we can show the anterior chamber better.
So, trabeculotomes come two directions one to the left and one to the right. I’ll show you this one. The other one is a mirror image. You only use the bottom rod – the top one is just to give you a reference as to where the bottom one is.
Because when you rotate this in you want to be in the plane of the iris.
I’m going to rotate it in now, so watch here. OK. And there’s a little bit of blood which is normal.
And I didn’t rotate it 90 degrees because I didn’t want my chamber to collapse yet. Going the other direction now.
And now I’ll go past 90 degrees this time. OK.
And I’m with my traction back on I’ll take the 9-0 nylon.
There’s really not much resistance when you do that. These might filter for a while but… with no antimetabolites it’s just going to seal off. And the reason I don’t like trabeculectomy so much is that you have to put so much Mitomycin on them that it blebs end up very thin and cystic. In order to get the bleb to work, it becomes so thin and cystic that there is a significant risk of endophthalmitis lifetime. So this little bit of blood is anterior chamber… I usually don’t bother to irrigate that out. It’ll be there for a day or two and then be gone. You see the same thing with goniotomy.
Trabeculotomy me has the advantage of being able to be performed in all glaucoma patients, whereas goniotomy you can only do an eye with a clear cornea.
Goniotomy is a nice technique. The problem is I imagine especially in… usually in developing countries the referral system is not very prompt. And so the patients arrive late with cloudy corneas. I think you can do either one. It’s pretty much surgeon’s choice when you have a cornea that’s relatively clear like this.
The reason I chose trabeculotomy is that… if you’re going to learn one technique that you can do on every patient, it’s trabeculotomy.
So because the underlying problem is a dysgenesis of the angle, you could do this surgery on anyone with congenital glaucoma. And the nice thing is that once you open the angle, if you get a pressure result that’s favorable, it’ll stay that way forever.
Something I think is interesting about this patient is relative lack of Haab’s striae and cornea scarring.
Question: Did you measure the intraocular pressure?
Dr. Neely: Oh yes, good question. We did it at the start. It was 31 on the right eye and 35 on this eye.