Surgery: Pediatric Posterior Lenticonus Cataract

>> This is the left eye of a young three-year-old patient with posterior lenticonus. The patient has 2.75 diopters of corneal cylinder. You can see the axis of the intended implantation of the toric lens placed on the cornea, with inkless marks. We’ll go back to that later. But you can see the posterior polar lenticonus opacity. We’re gonna inject some Trypan blue, which I think helps not so much to visualize the capsule, but it really can enhance and reduce some of the elasticity of the capsule, to enable a more stiff capsulorrhexis, to help with these pediatric cataracts. And we use it routinely. Using now a soft shell technique here, with our standard viscoelastic, dispersive, followed by a cohesive, and then we’re gonna use a superviscous agent here, Healon 5, which really is a fantastic way to really flatten the capsule. Of course, our first concern is performing an adequately sized centered continuous capsulorrhexis. And we’ll start the tear with the sharp tipped Utratas, and here initiate our capsulorrhexis. You can see we’re gonna use a combination of both a shearing technique, which is folding the flap over, as well as stretching here. You can see here at certain times we’re gonna basically unfold the flap and allow the tear to occur by stretching the capsule, to propagate the tear. And this helps to prevent that rhexis from running out, which of course is a concern in these young pediatric lenses. Again, the Trypan blue has helped us, as well as the use of the superviscous viscoelastics. Now, we’re gonna avoid any hydrodissection. In my opinion, these are contraindicated in this example. But we’re gonna do a little bit of anterior manual hydrodissection. Just to loosen up some of that cortex, to enable — help with cortical removal. And then we’re gonna do some good hydrodelineation, to separate the endonucleus from epinucleus. This will help us to remove the central endonucleus first, followed by epinucleus. Of course, this being a soft lens, we’re gonna use the irrigation/aspiration handpiece to first remove the central endonuclear — central zone here, using the I/A handpiece, and then chipping away here, removing the epinucleus, 360 degrees around the periphery here, avoiding the central plaque here, leaving that ’til the end. You can see I’m using a Kuglen hook here to keep that plaque down, so we don’t aspirate it just yet. The final position here, with that posterior aspect of the epinucleus, which we remove with the posterior polar opacity — and you can see we’re using the Kuglen hook to help aspirate it out. You can see what’s left is of course the pigmented area along that posterior capsule. It does look like it’s fairly thin, if not necessarily intact. And you can see the posterior outpouching here in this example of this posterior polar — or in this case, you could argue lenticonus — eye. 27-gauge sharp needle is used to incise the central posterior capsule, after injecting viscoelastic in the AC, as we saw earlier, and then we’re gonna inject some dispersive viscoelastic here, to separate and keep the posterior capsule away from the anterior hyaloid, and injecting that into Berger’s space. Then we’re gonna use the micrograsper to perform the posterior rhexis. Of course, performing the posterior rhexis here, which we do for all our pediatric cataracts less than the age of 4, and of course what’s important here is to prevent any visual axis opacity, which is of course a concern in these young patients. Of course, this patient has as well this posterior polar opacity, which we need to remove here, to enhance the visual rehabilitation. So doing a posterior capsulorrhexis here, not too different from doing an anterior rhexis, although you can see of course we’re working in a steep angle, with our instrumentation. And there’s very little, of course, countertraction. And there’s less tendency for any feedback, tactile feedback. You see here we’re injecting some more viscoelastic to ensure we’ve kept the chamber formed, and we’re using here really a combination of, again, shearing and stretching techniques here, to ensure this rhexis is adequately sized. It’s important to make sure it’s gonna be adequately sized here, because we are gonna eventually end up capturing the optic of the lens through this posterior rhexis. So again, a good 4 millimeter plus 5 millimeter, so if you can, it’s important to do this. Now, we usually err on the side of making them a little smaller. You can see both the anterior and posterior capsulorrhexis here being made with the posterior rhexis slightly smaller than the 5 or so millimeter anterior rhexis that was made. Now we’re gonna inject some cohesive viscoelastic here to separate the anterior and posterior capsule leaflets, prepare preparation for the lens implantation, and now this single piece clear toric lens — this is a ZCT400 TECNIS lens — is injected into the capsular bag first. We’re gonna rotate the lens into its approximate position, slightly underrotating it here, if we recall where the marks were made. Now, this lens will account for about 2.75 diopters of corneal cylinder. And this basically accounts for this patient’s cyl. Our goal here is really to maximize this patient’s visual potential here as a youngster. We’re gonna dry the cornea here. We’ll point out the marks. Again, there’s no ink here. We use an inkless system here. Just causing a bit of an epithelial divot. You can see I’m pointing it out right there. And then we will rotate the lens into position here, using a cannula. Now, again, we’ve got viscoelastic in the eye, in the capsular bag here, to facilitate that. We will then at this point remove a little bit of viscoelastic from in front of the optic and behind the anterior capsule, just here to remove some of that from the capsular bag. You can see we’ve used different viscoelastics here. Very important to use the right viscoelastics for the right purpose. And we’ve used dispersives, cohesives, and superviscous cohesives, as needed in this case. Typically using a 10-0 vicryl suture to close that incision. Initially, at least, it’ll be temporarily closed and cinched down here. At this point now, we’re gonna posterior optic capture this lens by pushing down on one pole of the optic, away from the haptics, getting underneath the posterior capsule, and now positioning the nasal optic underneath. Now we see the cat’s eye appearance of the posterior capsule, nicely fixating the lens in position here, aligning it with the intended axis of implantation here, along that steep axis of the cornea, which is approximated to be 85 degrees on our calculation. We’re gonna rotate the knot in place here. And you can see this lens really is nicely positioned. We prevent any rotation with that capture. And of course, what’s key here in this case is to prevent any secondary visual axis opacification. And we feel that avoiding an anterior vitrectomy here is a benefit. There’s really no place for those cells to grow along the posterior capsule or the anterior hyaloid, and this has been our preferred approach for pediatric cataracts, and of course, these posterior polar lenticonus eyes as well.