This video demonstrates a surgical technique of capsular tension segment for profound zonular weakness during cataract surgery. This young patient presented with an isolated ectopia lentis and superonasal lens subluxation.
Surgeon: Dr. Ike K. Ahmed, University of Toronto, Canada
DR AHMED: This video demonstrates the surgical technique with the capsular tension segment for profound zonular dialysis. This is a case of isolated ectopia lentis with a superonasal crystalline lens subluxation. We’re starting off with an inferotemporal localized conjunctival peritomy, which will be essentially the area where we will fixate the segment to the sclera. And the groove we’ll make initially — I like to make a partial thickness — basically 1/4 thickness groove, 1 millimeter back from the spur. The spur, again, is the transition zone between the blue zone and the white sclera. In this case, this will be 2 millimeters back from the limbus, but the spur is really the landmark to look at. That’s the consistent landmark we look to base upon which this groove is made. This groove is gonna be, in this case, about 3 or 4 millimeters in length. In the area of the dialysis. We then want to make three conjunctival incisions. These are a millimeter in size. This will provide access to the anterior segment, as well as ports for needle passage, as we’ll see shortly. We’ll then inject some dispersive viscoelastic in the area of the dialysis. It’s very important to keep that area tamponaded and coated with the right viscoelastic, and then a cohesive agent injected in a soft shell modified technique. And then a clear corneal incision is made. Here we’re gonna make three incisions here, at the posterior limbal area. These are relatively non-beveled incisions that will be used, small incision here, half a millimeter in size, for the iris retractors. This is a superviscous agent, viscoelastic here used to viscodilate the pupil, as well as flatten the anterior capsule. You can see exposure is gonna be a challenge here, so using a superviscous agent is very, very helpful to provide exposure, as well as pressurize the anterior segment and flatten the anterior capsule. A sharp tip micrograsper is used to pinch on the capsule here, in the visual area here. You can see the lens is quite subluxed, and we’re gonna start this tear. In this case, the tear wants to go in a clockwise fashion. So we’ll start the tear. It’s very important here to create a tear that’s relatively centered on the capsule-crystalline lens complex. It’s hard to see, of course, but we can visualize parts of the capsule here. And then we’re gonna use multiple incisions here, placing our micrograsper through different incisions to provide the best access. And in our non-dominant hand, in this case, using a Kuglen hook to help expose the portion of the capsule. The rhexis here is important, to make sure it is small enough that it doesn’t encroach the capsular equator, but not too small, where it will be difficult to perform the lens extraction. You can see here now we’re using another incision with the micrograsper to carry along the capsulorrhexis. This rhexis in this case will start off ovalized, of course, because the lens is somewhat microspheric and oval, and as I said earlier, what’s very important is to ensure that we retain the anterior capsule shelf, particularly in the area here centrally, as we proceed with the capsulorrhexis. This is very important to ensure we have a shelf to place iris retractors, as well as for the segment to be placed in that quadrant. Here you can see we’re using our non-dominant hand now, through the inferior paracentesis port, to continue with the rhexis here. And with the use of the superviscous OVD, this really helps to prevent the rhexis from running out, but keeping that capsule flat, keeping that anterior chamber pressurized. So fortunately, we were able to continue and perform a continuous curvilinear capsulorrhexis, which is critical for this procedure. One really has to ensure that rhexis is continuous and curvilinear. Here the iris retractor here is used in a modified fashion on the capsulorrhexis edge. One can use capsular retractors here as well, although when we use a segment, there’s really no need for capsular retractors here. We essentially use iris retractors here, and you’ll see we use it along with the segment. But first, before I put the segment in the eye, it’s helpful to have these retractors in the eye, basically holding the capsulorrhexis in place here. Lifting up on the capsulorrhexis to facilitate placement of the capsular tension segment. Here we’re gonna use the superviscous OVD again, to create some viscodissection. You’ll see how well the peripheral capsular bag expands with the use of this cohesive agent, separating the cortex from the capsule, creating space for the CTS to be placed in this quadrant. And we’re gonna do this basically for about 180 degrees in the vicinity of the intended placement of the segment, and you can see having those iris retractors here really helps on the rhexis edge to hold that capsule in place during the injection. Remember, these are low flow states. There’s really minimal risk for those retractors to tear the rhexis. But you’ll see we will move them off the capsulorrhexis during the lens aspiration stage, for the concern, of course, where there may be focal tension on the rhexis. Here’s the segment being placed carefully through the clear corneal incision. You can see it’s got a leading eyelet, a trailing eyelet, and a central eyelet that will be used for fixation. In this case, with an iris retractor, and later on with a suture. This segment is rotated here, ensuring that the comma-shaped central eyelet is placed anterior to the anterior capsule, while the leading and the trailing eyelet is placed and deposited under the capsule here, with the Sinskey hook. It’s hard to see sometimes, but it’s important that the segment, of course, is entirely in the capsular bag, except for the central comma-shaped central fixation here — eyelet that we see here, placed anterior to the anterior capsule. At this point, we can release the central iris retractor, turn it 180 degrees so it’s pointing up, and then essentially place that retractor through the central eyelet. This can be facilitated with the use of a micrograsper, holding the comma-shaped central eyelet, and placing the iris retractor through that eyelet, and then pulling down on the sleeve. Now, it’s important not to pull too much on this retractor at this point. For the segment may actually torque and flip out of the bag. We’ll then release the two remaining iris hooks that no longer serve a purpose. You can see how the bag is well supported by the fundus of the segment, which expands the capsule to the equator and secures the lens in place. Notice again that we’re avoiding excessive tension. Some hydrodissection is performed, and we can proceed with the aspiration here. In this case, we’re using the I/A handpiece. This is essentially a clear lens in a young patient. Essentially aspirating out the cortex. You can note in this case we have not placed the CTR yet. Because we had adequate support with the CTS in place, and we’ll put the CTR in later. And we’ll carefully remove all that cortex here, eventually ensuring the bag is completely evacuated. Easier to remove this, of course, when the segment’s in place, as opposed to a CTR, which can trap that cortex behind the device itself. Before coming out, we’re gonna inject the viscoelastic — cohesive in this case — to prevent the chamber from shallowing. Prevent vitreous prolapse. Absolutely critical. Vitreous presentation can certainly complicate things, and we’re gonna add more dispersive here, in addition to the cohesive that was earlier injected to coat the area of the dialysis. In this case, you’ll see when I release the iris retractor from the segment, again, with the use of a micrograsper, releasing it, and bringing the segment out of the bag and into the central anterior chamber, more dispersive is injected again to tamponade that vitreous face, create some space, and the segment is now turned 90 degrees in the central anterior chamber. More viscoelastic being injected again. And you can see we’ve used different types of viscoelastics for different purposes. This is a 7-0 Gore-Tex CV8 needle, double armed. We’re gonna straighten the needle out. We find an ab externo technique helpful in passing the needle. And a straight needle is helpful here to dock the needle into a 25-gauge hypodermic needle, as we’ll see shortly. So we basically straighten it out with two heavy needle drivers. We’re gonna go to one edge of the groove here. Try to centralize the fixation here, perpendicular to the sclera. Very important. Enter perpendicular. And then straighten out the needle to enter the anterior chamber. 25-gauge, again, through that groove in here. One end of the 7-0 Gore-Tex is used to dock the needle with the hypodermic needle, through the eyelet of the CTS, as we see here, and pulling out the needle through the groove. The CTS is then reposited back into the capsular bag, where it was initially, and we’re ready for our second pass to be made. The second pass will be made 2 millimeters or so away from the first pass, as we’ll see through that groove. Again, with a 25-gauge needle. And you can see the segment back in place, ensuring both eyelets are in the bag, with the central eyelet outside the bag. Again, perpendicular entry, and then straightening of the needle into the anterior chamber. Perpendicular helps to ensure that this device will be positioned adequately posterior, to avoid iris chafing. And again, we went 1 millimeter back from the scleral spur initially for that groove. The use of a micrograsper can be helpful to ensure that needle stays in the docked needle. The suture needle does. And this suture needle is then placed and pulled out through the groove. Now we have a continuous pass. Shorten that suture. This is the short end and the long end here. We will then tie the suture here in a slipknot, two throws and a single in the same direction here. The slipknot will help us to tighten or loosen the suture, depending on the centration of the capsular bag. To secure this, it does help to have a third hand here. Here we’re gonna basically hold the underlying suture, while pulling on both loose ends to tighten that knot out. It helps to have that knot cinched down, so we can pull it and loosen it as we need to. And then tighten it here, as we see here, toward one end of the sclerotomy that was made with the 25-gauge. And that will help to bury it, through that sclerotomy. You can see how we’re ratcheting up the tension in the capsular bag. We still have not fully tightened things up, and the use of a CTR will be used now, injected through an injector into the capsular bag. This will help for circumferential tension, expand the capsular bag, and allow the capsular bag to be positioned in a central position. It can sometimes be difficult passing the CTR around the CTS. Just be careful to ensure there’s enough OVD in the capsular bag, prior to injection, and sometimes some twisting and turning can be helpful to get around the CTS. We’re gonna enlarge the incision slightly here to over 3 millimeters, to allow an in-the-bag placement of a single piece acrylic lens. In this case, it’s a toric. This patient had 2.5 diopters of cylinder. As you saw, it was marked here with-the-rule. And the IOL is injected safely into the capsular bag with the haptic going into the capsular bag here, both the leading and the trailing haptic. We’ll then position the IOL in position here. And you can see that the IOL is starting to maintain a good central position here. Now, because this is a toric lens, and even for routine cases, we like to remove the viscoelastic here manually, as opposed to with the I/A handpiece, at this point. And you can see we’re injecting and aspirating the OVD from behind the lens. We do find that refraining from automated removal at the conclusion of the case helps prevent vitreous prolapse, which is still certainly a concern. So we prefer to remove viscoelastic manually, both behind the lens, in front of the lens, and from the anterior chamber, as much as we can. Really important to do that when the lens is a toric lens. We’re gonna tighten up the tension even more. So you can see from the beginning of the case, we’re tightening up the tension onto the CTS, further and further, and you can see the lens now is in a much better position. We avoided pulling on the CTS too much at the beginning, because one can lead to the CTS torquing out of the bag initially. Now we basically cut the short end and lock the suture in place. This is the third throw in total here. And this is a locking throw, to lock that knot in place. We’d like to cut the suture, about half or a quarter millimeter in length. A bit of Miochol here, just to bring the pupil down, ensure there’s no vitreous in the anterior chamber. You can see the IOL is well centered and on the axis of the intended corneal marks. We’ll then rotate the knot with a pair of microneedle drivers. With one jaw here used to place a knot into the sclera, and preferably rotate it into the eye, to prevent any risk of erosion through the conjunctiva, which certainly can happen if it’s left out of the groove. We’ll then close the conjunctival peritomy with 10-0 vicryl, and the main incision will be closed again, with the same suture typically using an X mattress suture to close that. These are all the detailed steps, step by step techniques, using a single CTS. Sometimes we use two if needed, but in this case, we use one. With Gore-Tex suture, suture to the sclera, placed along with a CTR for adequate fixation. In this case, with a toric IOL in a young patient with isolated ectopia lentis.
December 18, 2019