This surgical technique for congenital and pediatric cataracts using PCCC and posterior optic capture is the preferred technique for the surgeon. In this case with high corneal cylinder, a single piece toric foldable IOL was used.
Surgeon: Dr. Ike K. Ahmed, University of Toronto, Canada
DR AHMED: This three and a half-year-old patient has oil droplet lamellar cataract and has two and a half diopters of corneal cylinder present, and is marked on the steep axis at 85 degrees. We’re gonna start with injecting some Trypan blue into the anterior chamber. This is not so much important for visualization of the capsule here, but more important to stiffen the capsule up, to help to perform the continuous capsulorrhexis, which will be critical for successful IOL implantation. Some dispersive and cohesive in a soft shell technique, and then a clear corneal temporal incision is made. And then we’re gonna inject some superviscous cohesive agent like Healon 5, in this example, that really helps to pressurize the anterior chamber and flatten the anterior capsule. In effect, really creating a concave appearance of the anterior capsule. The sharp tipped Utratas are started in central capsule to initiate the tear. And then we’re gonna very carefully construct this capsulorrhexis to approximate 5 millimeters or so in the central anterior capsule. The capsulorrhexis here is being propagated using a shear technique. But we also will convert, if we need to, to a partial stretch technique, as we see here, and the stretch technique helps us to bring in that capsulorrhexis. Of course, the concern in these very elastic capsules is capsular runout, which is a high risk, which is avoided with the use of Trypan blue. Superviscous cohesive agents. And using a stretching technique for capsulorrhexis. Hydrodissection is performed, and then hydrodelineation helps to propagate the endonuclear from epinuclear separation, and will facilitate the removal of these soft lenses. I/A is really all we need to use to remove the central endonuclear opacity, as well as the epinucleus and cortex. And the bag is nicely evacuated here at this point in time. Now we’re ready to perform the posterior capsulorrhexis. We’ll inject some cohesive viscoelastic into the capsular bag and anterior chamber, and a sharp tipped 27-gauge hypodermic needle is used to incise the central posterior capsule, bevel down, here. Followed by injection with the same needle, with the use of dispersive viscoelastic, to separate the posterior capsule from the anterior hyaloid, filling Berger’s space, and injecting further viscoelastic here, as we see here, through that small opening that is made. It’s important to keep the opening small and central. We have a radial tear right at the center of the central posterior capsule, intentionally made, of course. Then we use a pair of micrograspers to propagate this tear. It’s difficult to, of course, perform this capsulorrhexis by folding the flap completely over. So we’re gonna basically suspend it in a vertical fashion, using a combination, again, of shearing and stretching forces, to propagate this tear. Of course, the posterior capsule is very thin. And we have a different vector field than we typically would for an anterior capsulorrhexis. And you can see we really have to propagate that tear out, to bring it out to the periphery here. It’s important, again, to keep this rhexis of adequate size. We’re going to intend on doing a posterior optic capture technique with the IOL, and so we don’t want to make this rhexis too small, nor too large. And again, aiming for about a 4, 4.5 millimeter rhexis is ideal, to ensure the security of having the right sized opening. As you see here, again, we’re using an element of stretching techniques here, to propagate the tear. The anterior — the capsule here is actually elevated here vertically, and we’re essentially pulling in the right vector force, peripherally, here, and anteriorly, to propagate this tear. And again, this is the technique that is modified here, based on the fact that we’re operating on this very thin posterior capsule, with very little countertraction on the capsule with the posterior zonules, as compared to the anterior zonules, on the typically convex anterior capsule. So now once we’re able to continuously perform this capsulorrhexis, we have a continuous posterior rhexis, and we’re ready for the IOL. This is a one-piece toric lens that will be placed, injecting some cohesive viscoelastic here to fill the capsular bag. It’s very important, of course, to avoid any vitreous prolapse in these cases, and the use of viscoelastic is critical in maintaining the anterior chamber. This one-piece lens is now injected into the capsular bag. We first place the optics and haptic in the capsular bag here, extending the haptics into the capsule periphery here, aligning the toric lens along with the marks that were made on the cornea initially. Here in this case, 85 degrees. Once we have the IOL aligned exactly where we want to place this, in this case, we will then prepare the IOL for a posterior optic capture. This technique involves prolapsing one pole of the optic behind the capsular opening that’s made initially here. One will have to tilt the lens fairly aggressively here, to get it behind that capsular opening. And then tilting and pushing posteriorly on the temporal side of the optic, to create this buttonhole effect or optic capture effect, of the optic through the posterior capsule. And you can see the cat’s eye appearance of the posterior capsulorrhexis that was made, both the nasal and temporal side, and this really is the ideal technique — in our hands, certainly — in pediatric and congenital cataracts. We avoid the need for a vitrectomy in these cases here. There’s no space for these cells that will — these lens epithelial cells that typically propagate along the posterior capsule and anterior hyaloid. And the optic here really protects and maintains the visual axis to ensure and prevent visual axis opacification, which is, of course, one of the major concerns in performing pediatric and congenital cataracts. At this point, the viscoelastic is removed manually, using multiple injections and aspirations with a 27-gauge cannula and BSS. We do this manually. We avoid going back with the irrigation and aspiration handpiece, for concern that the eye can collapse, vitreous can move forward in these pediatric eyes, and it’s really certainly much safer in our hands to do this manually, as we see here. The 10-0 vicryl suture has been tied temporarily, and that will be locked in place and rotated into position. Posterior capsulorrhexis and posterior optic capture technique can be used with any three-piece or one-piece lens, as we show in this video. And has been our preferred approach for these pediatric and congenital cataracts.
December 26, 2019