Hi there, I'm Doctor Theresa Cooney and I am a comprehensive ophthalmologist and cornea specialist who practices at the Kellogg eye center. And today I'm going to be talking about extra capsular cataract extraction conversion. And there's basically two different two different things I'm going to mainly be discussing. I'm going to be discussing planned extracapsular cataract extractions. But the more traditional large incision that's been in years past. The smaller incision will be discussed elsewhere. And I will be, also be talking about converting planned phacoemulsifications to unplanned extracapsular cataract extractions. So, first we're going to start out with a brief history. Back in the 1700s, Jacques Daviel basically performed his cataract surgery in an amazingly enough four minutes. That's a far cry from the 15 minutes that we do today for Phacoemulsification. Much less, the sometimes several hour extra capsular cataract extractions that we do. He used no anaesthesia. There was no asepsis, so there was no sterile technique, and he also had no microscope. Obviously there were frequent complications, and these would include frequent endophthalmitis. Chronic inflammation because he would not remove his cortex. Capsule opacification, pupillary block glaucoma as well as uveal prolapse. So in the mid 1800s, Albrecht von Graefe came in and he had an improved knife that allowed for better wound apposition. And there has continued to be improvements over the last several hundred years. So what are the preoperative indications for extracapsular cataract extraction, or ECCE? Basically, a lack of phacoemulsification equipment, and this often happens in underserved areas overseas. Not so commonly, luckily, in the United States. Very dense cataracts that are too hard to phaco can have extracapsular cataract extractions as well as zonular concerns. Intraoperative indications include anterior capsular extensions during the capsulorrhexis, zonular concerns, or a nucleus that is too dense to remove during phacoemulsification. Contraindications would be insufficient zonular support for safe removal. And these are more likely to be better removed with intracapsular cataract extraction, or with a pars plana vitrectomy with a posterior approach for removing the cataract. So what are the advantages of extracapsular cataract extraction overintracapsular cataract extraction? First of all the incision is smaller. There's less damage to the corneal endothelium, and therefore less chance of developing afterwards, less induced astigmatism, and more stable and secure wound, and intact posterior capsule. This in turn causes a reduced risk of vitreous loss, better interact with the lens fixation, reduced retina complications that would include cystoid macular edena retinal edema and retinal detachments, reduced swelling of the cornea. An intact barrier between the aqueous and vitreous with less VEGF transfer and less endophthalmitis and a safer secondary surgery, if it was needed. Preoperative considerations that you want to look at. Pupillary dilation is critical. You want to make sure that you use preoperative topical mydriatics as well as cycloplegics and, and NSAID drops to try to maximize this. And if your pupillary dilation is not sufficient, then iris hook should be considered, or sphincterotomy if you continue to have poor dilation. The reason for this is that if nucleus expression is performed during extracapsular cataract extraction without a sufficiently dilated pupil, you can have significant iris damage, including iridodialysis. So first of all, we're going to start out with the incision. If you know that you're going to performing extracapsular cataract extraction, you often will prefer to do a superior scleral tunnel. If you're not sure whether you may do one or you may not, you still might want to do a superior scleral tunnel. And to do so, you need to do peritomy. The pictures below here depict how a peritomy is done. So basically you use two forceps and Wescott scissors, and you want to make a little snip in the conjuctiva. You can use the Wescott scissors to separate the conjuctiva from the underlying sclera, and you want to snip along the length of the limbus to the width that you would like. And in this case, it's usually about 11 millimeters, so you can mark it before the surgery. Once you have most of the adhesions removed, you want to perform Wetfield cautery. And you want to then create a paracentesis, depending upon whether you're right or left handed. Super temporally or super nasally, and then inject some viscoelastic material. So, this animation here just depicted how a superior scleral tunnel incision is created. So basically, you start making the incision 2 to 3mm posterior to the surgical limbus. The chord length should be about 8 to 12 mm. And the initial incision should be made as a limbal groove with a crescent blade. Then you want to extend the incision into a tunnel. And this anterior dissection or tunnel is made with a crescent blade where you're basically going to go into the previous groove that you made and tunnel into the clear cornea, which is an area of the vascular arcade. Initially, you want the toe down and the heel up, and then you want the toe up and the heel down. So that you're going along the contour of the eye. And this depicts it over here. This is a look from the side, and this is a look from the surgical perspective. And you can see there, how they're using the tunnel to make that incision. After the incision or the tunnel is created, you want to enter the anterior chamber with a keratome in the center of the scleral or corneal tunnel. And the anterior chamber at that point should still be filled with viscoelastic. The next step we're going to proceed to is the anterior capsulotomy. If you know or that you may possibly be doing extracapsular cataract extraction,. This should be done through the wound before enlarging the wound so that the anterior chamber stays formed more readily. The continuous curvilinear capsulorrhexis can be made as you normally would make with phacoemulsification, and then four relaxing radial incisions can be made from the capsulorrhexis. If you know again that you'll be performing an extra capsular cataract extraction or thinking that you might, you can instead opt for a can-opener capsulotomy. And for this, you use a cystotome or a bent needle to basically make an initial puncture inferiorly, and then you want to pull it centrally. Subsequent punctures are then made peripherally and pulled back to the previous puncture, kind of doing like a connect the dots puzzle. And each puncture site can then tear radially if its stressed, so you have to be careful for this. And it's done on both sides. And then when you're all done, you want to sweep with your cystotome, all the way around your can-opener capsulotomy to just make sure that your capsule is completely open with no adhesions. Next, we're going to proceed with nucleus removal. Again, we perform a hydrodissection just as you would do a phacoemulsification. And this would, in turn, loosen the nucleus from the capsular bag. And again, if there's any concerns that there may be zonular issues, especially if this is a very dense cataract, you want to be somewhat gentle with this portion of the procedure. The nucleus is then rocked up and down. So you basically take your cistotomia, embed it into the nucleus, and you rock it up and down. To just make sure that it's loose and starting to prolapse from the bag. And then you also want to rock it from side to side, and you want the nucleus ended pushing down so that the nucleus is tilted up towards you at the wound. At this point you want to proceed with widening the wound. So the scleral or corneal wound is widened to a midlimbal chord length of eight to 12 millimeters with scissors. Now, if you're performing phacoemulsification and you all of a sudden decide that you might need to convert, here are some of the signs that oops, things haven't gone as planned. And so it might be time to convert. If you suddenly notice that the anterior chamber depth deepens, that may be the sign that there's a capsular issue and we may need to convert. If the lens is beginning to look unstable you might want to consider it. If you have an incomplete capsulorrhexis or you have some radializations of the capsulorrhexis, you may want to convert. Or if you start seeing vitreous presenting into the anterior chamber, you might want to convert. Now if you are not planning this extra cap, but actually converting, you're going to need to make some changes to the incision. Most phacoemulsifications now use temporal clear corneal incisions. So at this point, you're going to need to widen your clear corneal incision as opposed to your scleral tunnel, to a midlimbal chord length of 8 to 12 mm, just as we did with the scleral incision earlier that we talked about, with a crescent blade, which provides better wound construction. Or you can use scissors, if things need to happen a little bit more quickly. This is the done at the time of the decision has been made to convert. And so, basically here you can see that they're using a crescent blade, but here you can see, again, they're just putting scissors into the eye while they're supporting the eye with a forceps. And just opening up using scissors to open the wound. If you've done a capsulorrhexis, you will now need to make those four radial relaxing incisions that we had discussed earlier to allow adequate room for the nucleus to express because it will not be able to express in whole from the small capsulorrhexis opening. In removing the nucleus, there's some consideration that you may want to give to placing a couple safety sutures, which you can see here, one on either end of the wound. And these can be done for quick closure in case of the unforeseen complication of having expulsive hemorrhage during the nucleus expression. A lens loop then is used to provide posterior pressure on the posterior lip of the wound, and then behind the nucleus once the expression begins to help remove it from the eye. So for the next step of the nucleus removal, you're going to also have a muscle hook available in addition to a lens loop. Once the nucleus expression begins, again you will have the lens loop placed on the posterior lip of the wound adding pressure. And then you're going to use a muscle hook to add some additional counterpressure on the surface of the cornea, rolling in in a superior rolling fashion with a muscle hook to assist in a nucleus expression out of the eye. So again, here are just some pictures of nucleus removal. Again, this surgeon decided to put some of these safety sutures in for quick closure in case the need arose. again, you can see that the lens loop is placed inside the eye, trying to get underneath the prolapsed portion of the superior part of the lens. Again, additional pressure is placed on the posterior lip of the wound, and additional pressure is placed. Again, you can roll a muscle hook across the eye to add more pressure. And it's basically rolled out of the eye and onto the lens loop. And here is what a nucleus looks like after it is expressed. Now there's also smaller wound nuclear removals that can be done, and then that will be discussed in another segment by another surgeon. And you can also fragment the nucleus using forceps or nucleus splitter and deliver in smaller portions. So the next portion is wound closure. Now you have this 11, 12 millimeter wound that you need to close. What you initially want to do is partially suture that wound using interrupted 10.0 nylon sutures. And this allows the interior chamber to become reformed because at this point, the eyes are rather flat and it can then be better maintained. But you still have to leave space to perform the irrigation and aspiration of the cortex, and to place the implant. Then irrigation aspiration is used to remove the cortex by stripping peripherally and centrally. And again, you want to be careful of the capsule edge just like you would with any cataract surgery. You can then polish the posterior capsule as needed, and this basically just shows a picture of that. Now, intraocular lens choices. If there's sufficient capsular support, you can put an MZBD intraocular lens inserted into the sulcus or capsular bag with IOL forceps. And at this point, you don't often have a distinct capsular bag because your capsulorhexis has split through your radial incisions, and so you're kind of placing it in the sulcus and or the capsular bag. This specific lens allows for a larger intraocular lens diameter and an optic that will then better fixate. If you don't have sufficient capsular support, you can either suture the implant to the iris or you can place an anterior chamber ontra, intraocular lens. Or if you're very brave, you can scleral suture an intraocular lens. At this point, you want to fill your anterior chamber and or your sulcus and capsular bag with viscoelastic to allow for the insertion of the lens. At this point you may need to cut some sutures, you want to measure your opening. You need at least a 6 millimeter central opening in your wound to insert a single piece intraocular lens. And once the intraocular lens is placed, you want to then remove the remaining viscoelastic with the irrigation aspiration port, and you will use the irrigation aspiration port if there's no vitreous present. If there is vitreous present, you're going to want to use the vitrector that will also cut and prevent issues with vitreous removal. So, for wound closure, you're going to place multiple interrupted 10.0 nylon sutures, and you are going to want to trim the ends. And either bury them or rotate them posteriorly away from the cornea so they don't cause discomfort to the patient. What is super, super important is proper wound reapproximation. You want an equal wound depth on both the anterior and posterior lips of the wound. You want to make sure that there's adequate suture tension to prevent corneal wound slippage and that would occur if you have too loose reapproximation, because this would cause against the rule astigmatism. But the same time you also want to avoid excess suture tension, which would cause a significant amount of with the rule astigmatism, so you want to just find that exact amount of correct suture tension. When you're all done, you're going to want to check your incision to ensure that it is watertight. And if the peritomy had been made, you want to close the conjuctiva with interrupted 8.0 vicryl sutures or with cautering. At the completion of the case, you may choose to give some subconjuctival injections of steroid and antibiotic. I typically do this only if there's vitreous that presents and I would use Decadron 4 milligrams or Kefzol 50 milligrams or Gentamycin if they're penicillin allergic. I then place 50% diluted betadine on the ocular surface and I cover the eye with maxitrol ointment, an eye patch, and a Fox shield. So for Postoperative Care, if there have been vitreous issues during the surgery, I will add a topical NSAID like Ketorolac to my topical steroid regimen. You'll notice that there's a steady improvement in vision. Not necessarily perfect vision the next day, but a steady improvement in vision, and I tell my patients it can take weeks to sometimes even months for them to get their vision. But they will ultimately have good vision. If there's a significant amount of width the rule astigmatism. Meaning astigmatism at 90 degrees, you're going to want to start cutting the sutures on axis, which you can get either from a manual keratometer or from a topography unit, beginning at about six weeks to make sure that the wound has adequate time to scarring. You want to delay the final refraction, until a couple weeks after the sutures are cut, so that you know that the refraction is stable and you're not going to get a shift in their glasses prescription. Now if there's a significant amount of against the rule astigmatism, meaning astigmatism at 180 degrees. You may need to have to consider a secondary surgery because it's likely that the wound slipped and you need to reapproximate those wound edges in a better fashion. So the keys to a successful case. It's never it, it's never necessarily a super-smooth case. And there's going to be difficulties that present, even if you know you're going to have a planned extracapsular, cap, extracapsular cataract extraction, but especially if you're going to have to convert to an extracapsular cataract extraction. But the key is to stay calm. if you are get all upset things are not going to go nearly as well as they should go. What is super important is good wound construction, good wound closure. Again you want to make sure your iris is dilated appropriately and that you have a good size capsulorrhexis with radial extensions to prevent for adequate remove of the nucleus from the bag. And again, you want to make sure that the lens adequately mobilized so that it will present easily from the bag and out to the external part of the eye.
