Cataract surgery is performed on a 4-year-old boy with congenital cataract. A vitrector is used to perform anterior capsulotomy and lens aspiration, an IOL was implanted in the bag and a primary posterior capsulotomy was then performed through a pars plana approach. This is a standard technique and similar to the one used for the Infant Aphakia Treatment Study (IATS).
Surgeon: Dr. Daniel Neely, Indiana University
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DR NEELY: So this is the first of two siblings. It’s a four-year-old boy. Both siblings have congenital cataracts. They have an older sibling who’s had cataract surgery, and the mother had cataract surgery. This is a bilateral cataract, so we’ll start off putting in an infusion paracentesis. We’ll stain this capsule with VisionBlue next. So once we’ve stained the capsule, now we’re going back to that 20-gauge Lewicky anterior chamber maintainer. And now the vitrector. We have 250/250 again. So we’ve got the cutter turned off. Go ahead and turn the cutter on. So, again, we’re cutting our cut rate to 250, and we’ve got our aspiration at 250. And that’s just slow enough — since we’re not in the vitreous, we set it nice and slow, so that it will engage the capsule. And now I’m going to flip the handpiece over and take the cutter down. Starting in the middle, I’m just gonna start the capsulotomy. And you can see this nucleus — the lens is so liquefied, the nucleus is actually sitting down in the inferior half of the bag. So we really don’t want to use much vacuum on this, because there won’t be much to keep you out of the posterior capsule. You can see how friable this capsule is. It’s quite abnormal. So this lens looks like it’s partially reabsorbed already. You can imagine how difficult that would be, to tear a capsulotomy on this patient. The anterior capsulotomy — you still want it to be small enough that your lens isn’t going to pop forward during the second half of the procedure. I’m just using very careful aspiration right now. And again, this lens is very liquefied, and coming out in a very funny fashion. So we’re reaching out to the equator of the lens, and stripping, just like you would in an adult. Cortical clean-up. The material here is very sticky. The capsulotomy, when you cut it with a vitrector, it’s not quite as strong as the capsulotomy that you would get if you tore the capsule. So you don’t want to press on the edges too much. So I’m trying to reach without putting pressure on the edges of the capsulotomy. And again, I’m going to switch positions here, so that I can change my approach to the last subincisional area. Some people prefer a bimanual technique with this. Where they’ll hold the infusion in one hand and hold the vitrector handpiece in the other. And that’s a nice technique. It takes a little greater degree of dexterity with your non-dominant hand. And that’s certainly the nice thing about the anterior chamber maintainer, is it lets you continue using predominantly just a one-handed technique, and stabilize the eye with the second hand. Tease out this last little bit here. Now that we’ve got the cataract out, we’re going to put viscoelastic in, and we’re going to enlarge our wound. So we’re taking our infusion off now. So we’re getting our lens prepared now. We’ve got a capsulotomy that’s about 4.5 or 5 millimeters. And you can see how, even though we cut that with the vitrector, it looks round. Right? So the vitrector takes little bites out of it, but those little bites all tend to roll under the edges. And so it ends up forming a circular opening, even though, if you could unroll the edges, it would look scalloped. And there are several ways to do this. You can go ahead and do the posterior capsulotomy now, and then inject your lens or fold your lens in with the posterior capsule already open. You can put your lens in and reach around the lens implant from the front. Kind of reach underneath it. And do the posterior capsulotomy. Or you can go through the pars plana right here. So this is a +22 lens. This lens was selected because this child is four years old, and we wanted to allow for some growth still. Postoperative target refractive error for this child is to be a +2, about six weeks after surgery. After about age eight to ten, we’ll start aiming for closer to emmetropia at that point. This is 10-0 vicryl again. And again, the reason that we like this is because it is absorbable. We won’t have to do a suture lysis. Pretty much no matter how tight you tie that, you’re not going to induce more than half a diopter of cylinder. And I’m going to put a temporary tie in this, and then I’m going to take the viscoelastic out. We just turned our infusion back on. You can see our viscoelastic is removing itself for us here. And this is why you want a slightly smaller anterior capsulotomy. Because as this starts to fluctuate, when we’re opening the posterior capsule, it’ll keep that lens back there and not push it forward. We’ve just dropped our infusion pressure down to about 20, so we can tie a more normal intraocular pressure. Now we want to go on to the second part, to open the posterior capsule. Now, in this child, the pars plana — at age four, the pars plana is going to be back 2.5 or 3 millimeters. So I’m gonna open the conjunctiva up. And you see I’m going off to the edge slightly. Don’t want to cut down on the superior rectus. You can take this down at the limbus, or you can go back, trying to leave the limbal conjunctiva intact. I generally try to leave the limbal conjunctiva intact. We’re gonna aim for the center of the eye, or even aim towards the optic nerve. And we want to see this blade come out behind the lens capsule. So now we’re gonna go in, and remember, our infusion is in the front. I am gonna enlarge that a little bit, but before I do, I’m gonna do a little vitrectomy here. It looks like there’s some viscoelastic back here too. And you have to remember that you’re gonna — you need this to be — you don’t want to be so large that you destabilize the lens, but you want it to be large enough that you can refract through this later on. And I’m gonna come forward here and just turn the cutter off for a minute. I think we still have a fair amount of viscoelastic in the front. I’m gonna take some of the pressure off here. Just getting a little bit of viscoelastic out of the front. It seemed like the lens was wanting to push back. And I think that there was a little bit of viscoelastic up front here still. The complications are that you can, as you enter, of course, the pars plana may not be normal. You can create a retinal detachment. I have seen that happen a couple times. But in general, despite our trepidation and, for most of us, lack of experience doing this, that typically is not an issue. You can see here the disadvantage of not taking the conjunctiva down at the limbus. You end up getting a lot of fluid under the Tenon’s, and the Tenon’s hydrates, and kind of gets in the way of the suture here. So we’ll put a 9-0 nylon across this sclerotomy. We’ve dropped our infusion pressure down a little bit, so that we can tie this and close it easier. And we’re just gonna put another X of vicryl across this. Try and keep all that Tenon’s in, out of the way. And you can see that chamber shallows. That’s one of the disadvantages of soft pediatric sclera and corneas. They don’t really — the wounds don’t seal very easily. I’ll do a little stromal hydration here. And this is why we pretty much never do sutureless pediatric cataract surgery. All right. So this was a pretty standard vitrector-type pediatric cataract surgery that I would use on anyone under age five. And this is the standard technique that was used for the Infant Aphakia Treatment Study.
June 15, 2017