In this lecture, Dr. Fonseka talks about the complications of cataract surgery and how to manage them. He talks about the complications related to cornea, capsular bag and iris complex using slides and surgical videos.
Lecture location: on-board the Orbis Flying Eye Hospital in Mandalay, Myanmar
Lecturer: Dr. Charith Fonseka, Nawaloka Hospital, Colombo, Sri Lanka
DR FONSEKA: Thank you very much. Good morning again. So the topic I’m going to discuss today is the possible complications of cataract surgery. And like yesterday, it’s always good to have in your mind a division of the possible scenarios in which complications of cataract surgery can occur. And for me, these are the main areas which I need to watch out for, which I see complications in, so the first one is relating to the cornea. And the second one is anything relating to the capsular bag-iris complex. So that’s both the capsule, as well as the iris. Third is relating to retina and vitreous. I’m not gonna really touch upon that today, because that’s a different sort of complication that would be encountered. And the last is relating to inflammation and glaucoma. And that’s something which we also need to keep in mind, though we do not see it very commonly. Now, if you look at corneal injuries, postcataract surgery, they can result from two major etiologies. First of all, there can be direct trauma to the corneal endothelium, and that is possible with either the instruments, the phaco needle itself, or the second instrument, and if you accidentally hit the corneal endothelium, then it’s going to cause very, very significant damage to the cornea. And at best, at best, you can just hope that it will just cause a little bit of striae the following day, and recover due to endothelial cell migration over the next couple of days or weeks. But if it is anything more than that, then that’s going to lead to corneal decompensation, and then this patient is possibly going to end up with getting an endothelial graft — that’s a DSAEK or a DMEK — done. So that’s one of our great fears. Working anywhere near the posterior capsule. We try to avoid working near the posterior capsule. That means we tend to bring the fragments up into the anterior chamber, very close to the endothelium, and these can accidentally hit the endothelium, causing endothelial injury. So that is by far the commonest way in which endothelial injury occurs. Something which we do not keep in mind a lot of the time, when we do phacoemulsification, is that excessive fluid, the fluid which runs through the eye, will also cause endothelial damage. It’s going to cause a washout on the endothelium, and there will be endothelial damage. And that may not be clinically obvious in the initial phase, but for a patient who has endothelial — the endothelium compromised from other reasons, it can be very, very significant. So that’s something which we also need to keep in mind, that the amount of fluid used can also have a deleterious effect on the corneal endothelium. Another way in which the cornea can get damaged is due to the Descemet’s tear. Now, this usually occurs at the sites of injury. So either at the main incision or the side ports. It’s common with the main incision, and this can occur right at the inception, when we are using — doing the phaco. You’re putting the phaco handpiece or the phaco needle tip through the main incision, that can cause detachment of the Descemet’s membrane. It can also be — you can encounter that during IOL insertion. The most important thing about Descemet’s detachments would be the size. So the bigger the size, the higher the risk, and the second one is that you should be able to recognize it in its early stages. Because if it is recognized and managed, the consequences are very little. You can reattach it. You can just put in an air bubble, and reattach that endothelium very nicely. Sorry, the Descemet’s very nicely. And clinically, the patient would be fine in a day or two. So that’s extremely important to remember, and the critical thing about Descemet’s tears is that it is important to be able to recognize it immediately. So always watch out. Especially in the subincisional areas. For Descemet’s detachment. So now we come to the next part of the complications, which is what we are always very concerned about, when we do a phacoemulsification. That is: Any complication relating to the capsule. So we have to deal with two aspects of the capsule. One is the anterior capsule and the other one is the posterior capsule. And the anterior capsule — we can get anterior capsular defects, and the first one would be the incorrect size or shape. I have not included the shape, but the shape is also very important. Because ideal anterior capsulorrhexis would be between 5 and 5.5 millimeters. And it should be central, so that the periphery of the optic is entirely covered by the anterior capsular rim. So centration is important. And the size is important. So if you do not get this size or centration correct, then there is obviously at least — there is going to be a change in the patient’s expected refractive outcome. That can occur immediately, or it can occur subsequently. Because of movement of the lens. So we have got the size right, but we have not got the centration right, so therefore part of the optic is not covered by the anterior capsular rim, and this can cause a slight tilt or slight decentration of the lens. Which most of the time may not be significant, but in some cases can result in a refractive change, and that’s not something which we want to severely see. If the capsule size is too large, there’s really nothing we can do about it. We just have to deal with any refractive changes that will occur as a result of that. However, if the capsular size is too small, and I will tell you — I will show you what happens when the capsular size is too small. We can always deal with that. Now, in this patient, I have implanted the IOL, and if you can look at this, you can see that the capsular opening is really — there’s a risk of this patient developing capsular phimosis. So the pupil is also small here. What I’m trying to do is to try to remove a rim of the anterior capsule, and it is very safe here, because we just need to make sure we do not damage the endothelium. Just take a Vannas scissors, or a blade, and make two small nicks. So the eye is filled with viscoelastic. And then I have made two small nicks in the anterior capsular rim, and I’m going to use the rhexis forceps to try and pick it up. You can also do this with the cystotome. It’s entirely possible. So this patient’s anterior chamber is a little shallow. But it is possible to do this. So you just pick up an edge, and then just tear it right round. Make sure you do not go beyond the edge of the optic, because that again will have a deleterious effect. And that is done. So it’s a pretty easy procedure. You do not need to do it 360 degrees, because if you look at this, you can see that we have got the anterior capsule covering the edge of the optic, right round. We just need the capsular opening to be a little bit bigger, to ensure that there is no capsular phimosis in the future. So it is eminently possible to do this without any difficulty. You just need the Vannas, sharp. The Vannas scissors. The tip must be sharp, to be able to make two nicks. If you do not have a Vannas scissors, you can also use the cystotome to achieve the same thing. You can just make a nick with a cystotome, and use the cystotome itself to continue and remove the rim. So that is… Okay. So that’s as far as the incorrect size and shape goes. Whenever possible, try to correct it it, and in most cases, it is possible. Especially if it is small. However, the most important thing about doing the rhexis is to be mindful, always be very, very careful with the rhexis, because that is the most critical step in phacoemulsification. The other possible complications that can occur with the anterior capsule are radial tears. Now, if you get a radial tear, then it is necessary to try and salvage it. And you can always you make sure, if the radial tear is small, that that tear is incorporated in the rhexis. So you include that in the rhexis, and make this rhexis back again, a continuous rhexis. Without any edge. There are some situations in which that is not possible, and I’ll show you both cases, and then in those cases, you may have to decide to convert. Because if you have a large radial tear or multiple radial tears, then it is possible that if you continue with the procedure, with phacoemulsification, the fluidics and the pressure can cause extension of the radial tear to the equator, and then cause it to go beyond the equator, and once it goes beyond the equator, there is a serious risk of the nucleus dropping into the vitreous. Even if the nucleus does not drop, you can have lens matter dropping into the vitreous, and both are very, very bad, as far as the patient is concerned. So let’s see what we can do, regarding… So I showed this case to you again yesterday. And you can see I have got a radial tear. You can see those two radial tears there, and there’s a radial tear here. But the radial tears are small. And it is possible to try to incorporate that, as you can see. Now I’m going to incorporate that, and I’m going to make that — so that half becomes entirely circular. Now I have to repeat the procedure on this side, and this is the case I showed you where there is a calcification on one side, and therefore it is not possible to do a capsulorrhexis, and I’m going to use the Vannas here, to try and… So I’m using a needle here, just to initiate an edge. So that is again — if you look carefully, you can see that this edge is not continuous. So that side is fine. So I’m going up to the calcified margin, and I cannot go beyond that point. But this edge — I need to make sure that it is incorporated into the rhexis, and so I tucked that out, and we have got a continuous margin here. So that is continuous. And there is no risk of… But you can see that it is not possible to tear. I’m exerting a fair amount of force, and it is not possible to tear. Because of my attempt to tear that, I caused another radial tear at this point. Which I have to again incorporate into the rhexis by making it slightly bigger. And of course, you have to use in this case — I can change hands and use a pair of scissors to cut across the calcified plaque. And once I cut across the calcified plaque, then I have got a continuous capsulorrhexis. Okay. So that is the continuous capsulorrhexis. However, there are situations in which it is not possible. Where the anterior capsular defect becomes so big that at this point you need to decide whether you’re going to convert or continue. And this is a case which I always show my trainees.
October 21, 2019