Lecture: Rectus Muscle Plications for Strabismus

In this webinar, we’ll discuss the how, when, and why of plications. We’ll share some technical tips, and review how to use the surgical dose tables. We’ll look at what the literature says about plication versus resections, and look at some case descriptions.

Lecturer: Dr. Melissa Simon, Ophthalmologist, Brown University and Lifespan Physician Group, USA


Good morning, everyone. My name is Dr. Melissa Simon and I am a specialist in pediatric ophthalmology and adult strabismus. I’m joining you this morning from Providence, Rhode Island in the U.S. It’s a warm and very humid summer day here. It’s morning. And today, I’m going to be talking about rectus muscle plications for strabismus surgery. This is my first Cybersight lecture for Orbis. It’s a real honor to have the opportunity to talk with all of you today. I was able to participate in a lecture, in a tour, an Orbis week-long tour in Peru in 2012 when I was a resident and I just think Orbis is the most amazing organization. I’m really excited to be a part of this community again. I saw the registrant questions beforehand and I think I’m going to be able to answer almost all of your questions during the lecture today. So with that, let’s begin. We’re going to start with a poll question. The first question is, have you ever performed a plication of an ocular rectus muscle? We have 156 participants today. I’ve performed plications before. I’m curious how many of you have. So 40 percent of you have performed muscle plications before. 60 percent have not. And I’m hoping today that after talking, we’ll have a chance to convince you that trying plications are a worthwhile endeavor. To plicate means to fold. And so that is essentially what we do in the plication surgery. We take the rectus muscle and we fold it. We can do this to a lateral rectus muscle, a medial rectus muscle, a superior rectus muscle or inferior rectus muscle. I’m not going to be speaking about the obliques today. But we can plicate any rectus muscle. We fold the muscles once in a plication. It’s not a multiple folding technique. It’s really just like a towel. That’s what I tell my patients when I consent them for surgery in the office. Just to demonstrate today, I made a model with a towel. This is a salad bowl from my kitchen and I just drew the iris and the pupil on it. Here is a dish towel that I put some ciliary arteries on. And the idea of the surgery in a plication is to pass sutures through whatever distance we’re plicating and then attach that plication level to the original insertion so none of the arteries are cut or interrupted. You can fold it this way with the excess muscle underneath or fold it this way with the excess muscle on top. I will show you videos and we’ll talk about technique as we go. One thing we don’t want to do in plications is get too fancy. We’re not going to make anything complicated. No animal shapes when folding rectus muscles. Before we get into the meat of the lecture, I would like to ask another poll question. Plication surge like resection surgery, works by, A, tightening the rectus muscle, may recollecting the fibers of the muscle thicker or stronger or C, triggering a bio chemical reaction that grows more muscle fibers? 81 percent of you were correct. The surgery works by tightening the rectus muscle. Rather than by making the muscle fibers stronger. That’s a popular misconception if you chose B. We often call it plications and resection strengthening procedures but actually, what those surgeries are doing is creating a tether. This illustration from Ken Wrights third edition textbook is really helpful in explaining how that tether works for a resection or a plication. Either one. This muscle here is tightened and when the eye moves in the direction of that tethered muscle, it has, still, full swing. But the idea is when the eye looks away from the tethered muscle, there is a restriction and that’s how the surgery works to correct strabismus rather than actually changing the fibers and making the muscles stronger. And one of the most popular questions I received is why do a plication? And are plications and resections interchangeable? In my experience, plications and resections are indeed interchangeable and with one exception. If you need a biopsy of the muscle, then you have to do a resection because you have to get the piece of the muscle. But other than that, I think that plications work whenever you would otherwise do a resection. And there’s, there are data in the medical literature to support that. So on children, on adults of any age, horizontal, vertical rectus muscles, reoperation, new operations, adjustable sutures. We’ll talk about all of this. I think that plications are a worthwhile endeavor as a substitute for resection. The major reason is that it has been shown to reduce the risk of anterior segment ischemia. And so we all know that in order to do a resection or a recession of the muscle, these ciliary arteries that run over the top of the muscle have to be cut. And when we cut, you know, three or more of those muscles, the risk of anterior segment ischemia is much higher. It’s a rare complication of strabismus surgery but it’s a very bad one and we want to avoid it whenever possible. So it was first shown in animal models and then later in humans that the anterior segment circulation is indeed preserved with plication surgery. And so for me, that’s the major reason to do the surgery. Why not preserve the circulation if the procedure works as well. And I’m going to show you techniques today so that it will. Also, related to preserving the circulation is you leave open the opportunity for additional operations in the future. So you may only be doing one muscle today but two years from now you may need to do two different muscles. So if you’ve done a plication today, that opportunity remains if you have to do a recession later to interrupt those blood vessels without worrying as much about anterior segment ischemia. Other bonuses and advantages of a plication is the reduced risk of lost muscle. We know that with a resection, the risk of slipped or lost muscle is higher than with other surgeries like recession. With plication, there isn’t a risk of a lost muscle because we don’t dis-insert the muscle, we just fold it over itself. There is the possibility of early reversibility but I’m going to talk about adjustables as a plan if you think you’re going to want to reverse your procedure. You may not want to count on just undoing all of your work. There are reports in the medical literature that plications take less time. They cause less trauma, inflammation, and hemorrhage. And because of that, the recovery can be easier. Because the muscle is not being cut. And we can still do vertical transpositions of our horizontal muscles or adjustable techniques as I’ve mentioned with plications. I’ll show you that as well. And in my experience, the pain is much, much better for patients. I find that patients are so much more comfortable. Even the first day after surgery, compared to resections. The only contraindication is when a biopsy is needed. My sources are to the left here. In this talk today, I’m going to talk about attaching the muscle to the sclera. This is another illustration from Ken Wright’s third edition textbook. There was a question about muscle-to-muscle attachment. And there are doctors in our international community who have more experience with that. That’s a tuck and in my hands and in some of the papers I reviewed, muscle to muscle tucks for rectus muscles don’t seem to work as well as plications, at least in this moment in time. So what I’m talking about today, exclusively, is muscle to sclera attachment when I say plication, that is what I mean. Let’s pause for a poll question. The best conjunctival incision for a rectus muscle plication is A, fornix incision, B, limbal incision, C, modified Swan incision, or D, all are equally appropriate? We had a split. Interest. 42 percent of the audience said limbal and 40 percent said all are equally appropriate for the surgery. I created a best answer, but, actually, I think you’re both right. I think D is true. All are equally appropriate. But also the limbal incision might be a little bit better than the others. I’ll explain why. The limbal incision causes less interruptions to anterior segment circulation. So if your main goal is to preserve anterior segment circulation, I’m sorry not a limbal incision, a fornix incision. Sorry, I misspoke. The limbal incision is a fine choice but it’s really, the answer is D or a fornix incision. The fornix incision preserves the anterior segment circulation. If your main goal is to preserve circulation as much as possible, I would recommend a standard fornix incision if the patient is an appropriate case and if the surgeon is comfortable with that type of incision, 7 mm to 8 mm from the limbus. However, all incisions are appropriate for plication surgery. And in a plication surgery, still, the major ciliary vessels are being spared. It’s important for a surgeon to use whatever incision he or she needs to be able to see the field properly, do the work that is necessary, and to respect the tissue quality of the patient depending on their age and their medical history. So I’d like to talk about my technique. The first one I’m going to show you is based on Ken Wright’s textbook which I have been performing now for about five years. And then I’m going to show you another technique that I have recently started enjoying as well. So you start the procedure much like you’re going to do a resection. And so you can see in this photograph, I have two green hooks in the muscle. You can use two Jamesons as well. And it’s important the posterior hook doesn’t pull too high up to the ceiling. We don’t want to activate the superficial — we don’t want to stretch the superficial muscle fibers more than the posterior muscle fibers. You want to create an even plain of the muscle. And mark, I usually mark however many millimeters I’m going to plicate. We’ll talk about how many millimeters to choose in a little bit. And I take a marking pen and just mark the edge of my caliper and move the caliper across the muscle to make a nice clear line for myself. Then, I proceed with partial thickness passes through the muscle. Center to the edge. And I do not first do a lacking safety stitch. Many of you are used to doing a central full thickness bite here and tying it first in a resection surgery. And then doing the partial thickness passes. I would not recommend that in a plication surgery because it only adds more opportunity to strangle muscle tissue and we’re not worried about a lost or slipped muscle in a plication. So it doesn’t have a purpose. So here I’m showing you the partial thickness passes. I try to do it just behind my line. Again, avoiding going in on a vessel. And then I go in the other direction. And then I lock. So to do my full thickness bites and lock, it’s important to identify where the vessels are. So you can see this very large one here. On the other side there’s a big ciliary vessel here. I do the full thickness locking and try to avoid the ciliary arteries. You can see the knot here is just to the side of that. And you can ask an assistant or a technician in the OR with you to take a small hook or a non-toothed forceps or even a Q-tip to gently push the vessel towards the middle away from your knot while you’re tying if you’re worried you’re going to incorporate the vessel and strangle it. And I also try to get my locking bites right on that line of how many millimeters I’ve marked. Then once I’ve done that, the next step is passing the suture anterior to the insertion. Again, I want to avoid the ciliary vessels. So, you know, I do my best. You’re going to see some bleeding there. It looks like I got one of the more minor ones there unfortunately. I try to avoid them as much as possible. In front of the insertion, the sclera is relatively thick and we need a very secure partial thickness scleral tunnel with the suture in order for that scleral tunnel to withstand the tension that is going to be put on it when it’s time to pull and plicate the muscle. So you don’t want a really thin delicate tunnel. It has to be strong enough to with stand the pull that I’m about to show you in the next video. I do use absorbable suture. You do not need to use permanent nonabsorbable suture in this surgery. Over time the excess muscle in the fold atrophies but the muscle does scar to the sclera and the insertion in the spot you want it. So in this video, we’ll see that I’m tying this first as a three throw tie. I find the three throw very stable for the first throw. I pull up on the muscle to the ceiling and then in the plane of the eye towards the limbus for the second pull. And that folds the muscle. And you can see that happening now, I grab close to the edge of the knot. I’m not pulling from way out by the forehead and feet. I get as close to the knot as I can and pull up and then I pull parallel. And then up, and then parallel. And I do that a few times. I try not to pull with a lot of force. I try to be as gentle as possible. The muscle is folding nicely and you have a little bump here. You can take the hook out once the muscle starts to fold. I just left it in there to demonstrate in this video the fold. So after that, you can pull the hook out. Then I do a one, one, after the three throw. I find that the three throw does not move. It’s a very stable knot. And so then I do another one to lock it and a third one in case the Vicryl unties. You don’t need more than that. Actually, more knots than that will actually destabilize the knot. So 3, 1, 1 is plenty. In Ken Wright’s book he does 2, 1, 1. You can do that for sure. It’s a better approach for your tying if you’re doing to do an adjustable. A 3, 1, 1, is tight. If you do a 2, 1, 1 after the first throw with the 2, you need an assistant to take a non-tooth forceps or needle driver to stabilize the first knot. The first knot can be destabilized and you end up with a weaker plication than you anticipated. Now I want to show you a second technique and I just started doing this one. It is outlined in Dr. Ludwig’s textbook. The chapter is written by Monte Delmonte from University of Michigan and he advocated this technique, first I’ll show it do you and then I will explain why he advocates it. What we do in this technique — this is me practicing his technique. Or utilizing his technique. In this procedure we set it up the same. I mark how much I’m plicating and I do my first partial thickness pass through the muscle. Then I actually go back through the original holes. I go back through my hole that I exited the muscle here, and I exit the hole that I entered the muscle in, in the center. What that does is, in the second pass it’s more superficial. I’m just skimming underneath the ciliary arteries. And that way I’m setting myself up to do a full thickness bite, again, through the same hole in the center of the muscle. I’ve left this loop to lock it with. And you’re going to see now, taking that original hole, I’m going to pull it through that loop that I’ve created with that back and forth partial thickness pass. Usually we just do one partial thickness pass but then we did a second back to set ourselves up to lock it. This knot will create an air hole if you just pull this Vicryl here. So you have to stop yourself and pull back on the suture so that the loop is flush with your tissue. Once the loop is flush with your tissue, then you pull your Vicryl all the way through the tighten the locking bite. And this technique according to Dr. Delmonte will give you more security with the ciliary vessels. Because the locking bite is underneath the muscle, it will not strangle or put pressure on the arteries that are on the surface. And because you’re going back and forth through the muscle and then locking it from the center outwards, you can ensure that all of the muscle fibers will be incorporated in your plication without a central sag. And so in this case when I did this procedure then I passed the sutures anteriorly, anterior to the insertion, the same as I had demonstrated. You can do it with cross swords. I don’t do it with cross swords but you certainly can. In this case, I also did a vertical transposition of the horizontal muscle. So I did a half tendon width. You can see here the muscle kind of folding over itself at this angle because of the vertical transposition. The patient did really well. So the next question that was very common in your pre-lecture questions was, is this procedure really reversible? I know it seems kind of like folklore that you can undo it. You can undo it. Sort of, maybe you can undo it. It depends if you reverse the plication soon enough after surgery. Some folks say you have to reverse the plication within the first three days. And cut the suture completely remove it, take a hook and flatten the muscle out. Some people say you have up to a week to reverse the procedure. But certainly not longer than that. And if you’re going to reverse the procedure, you need to make sure that the conjunctiva is still well opposed in your closure. Because with all of that activity, you can stimulate scarring. If you anticipate wanting to undo the surgery, reverse the surgery, I recommend planning an adjustable technique. I think you’ll have more control and probably a better outcome. And we’ll talk about that. There is a really good paper from the journal of AAPOS by the group of ophthalmologists at UCLA who were early adopters of plications and do a lot of them. And they show a great series of cases of adjustable plications with a slip knot. So they do the original two throw and do a slip knot. They put in their anchoring suture in the sclera and adjust the patient after they wake up. There also are reports of using the noose technique. Doing the first two throw and then using a noose around the pull sutures. That’s a possibility as well. It seems a little more complicated to me with a lot of suture involved, but you could do that also. I haven’t done a plication on adjustables yet. I don’t have any of my own photos to show you today. But it has been done successfully. One tip that I noted by Dr. Delmonte is to incorporate a millimeter or 2-millimeters more than you want in the plication in order to have more room to adjust the patient after they wake up. So if you want to do a 6 mm plication, maybe plicate 7 or 8 mm so you have more to adjust later. Another question that I wanted to address briefly was what is Dr. Wright’s mini plication? This is a cool procedure that he does in the office under local anesthesia. He does this for small horizontal or vertical deviations. And by small, we mean less than 9 prism diopters. That is pretty small surgically speaking. In all cases, he advocates plicating the central portion of the muscle going 5 mm posterior. We don’t have a surgical dose table for this mini plication. We do have a surgical dose table for all other plications and I’ll talk about that. But for the mini plication, just 5 mm for all measurements, 6 prism diopters, 4 prism diopters, 9 prism diopters. They’re all 5 mm posterior. You grab the central portion of the muscle and put a full thickness bite of Vicryl around the central tissue avoiding the vessels that we want to spare. And tie it. Then plicate by doing your partial thickness passes through the sclera anterior to the insertion. And this plicates as you can see in the drawing, just the central portion of the muscle. So it’s less effective than plicating the whole muscle all the way across which is why it’s called a mini plication. Okay. So are plications effective? This was a very popular question. Are they really as good as resections? I hope to convince you that the answer is yes. Most published studies are case reviews. There aren’t many randomized control trials where we compare resections to plications. Most published studies address ex-op tropia. There is still a lot of work to be done to prove plication efficacy. But so far the information we have, the data we have is reassuring. So there was a very large systemic review, a meta analysis of horizontal plications in 2020. They found that there was no difference in the success rate between plications and resections. This is the largest meta analysis that’s been published. There was a lot of heterogeneity. In some surgeon’s hands, plications worked much better than others. And overall, the success rate was surprisingly low. But there was no difference between plications and resections. And there was no statistical difference in the mean amount of the deviation corrected. There was no statistical difference in patients who were under corrected after surgery. There was no difference in outcomes between exotropia and esotropia. As we mentioned, there are not a lot of randomized control trials or long-term data which we still need. The metal analysis did have adults and children. And there was no difference in outcome by age. So there isn’t an age that the too young for a plication. And there isn’t an age that is too old for plication. Do plications last? So as far as we know, the answer is yes. It’s still a relatively new procedure in the United States. It was reintroduced in 2010. So most of the literature available to me in the U.S. is still relatively new, under 15 years old. But Dr. Demer in Los Angeles was an early adopter of plications. He started doing them in 2012. Did a large review of his plications over eight years. He compared them to his previous resections, eight years of data. And found that over the eight years long term, there was no difference in the outcomes, who needed additional surgery, who did not. Who had successful correction. There was no difference between plications and resections. How many millimeters do I plicate? That is another very popular question. Some studies and some of our colleagues will advocate doing more millimeters in your plication than you would for resection. Typically, about half a millimeter more per muscle. I personally do not. I use the regular surgical dose table for resection and do that with the plication. That’s what Joe Demer does in Los Angeles and what Ken Wright does. There are studies to support either approach. There are studies that show maybe you should put a few more — a half millimeter for more each muscle. There are some studies that show that you don’t need to. I think that each surgeon is going to have to do their own evaluation of their own data. So you’re going to have to do a couple plications and see if you have a trend over or under correction. But in my hands, I do not get under-correction when I use the typical surgical dose table. I just treat these resections like they’re plications and proceed. So another poll question. After plication, how long is the physical bump of muscle, that bulge underneath the conjunctiva, how long is that visible to the naked eye? 6 to 8 months, 6 to 8 days, 6 to 8 weeks or the bump never goes away? Okay. 61 percent of you said 6 to 8 weeks and that is correct. Patients have no problem in my experience, no problem tolerating the bump as long as they’re prepared for it. If they don’t expect that bulge, they get really concerned about it. And track it very carefully. If I tell them ahead of time you’re going to have a big bump, your eye is going to be super red. That is normal. Then they can handle it. It’s not painful. They’ve been reassured it will go away. So this is one of my recent patients. She had a lateral rectus plication. When she looks straight ahead, you can’t see much but there is a bulge there after five days. A different patient that had a medial rectus plication, this is after a month. You really can’t see too much. It’s red, yes, a little bump. But it’s going to flatten really nicely. The muscle, the redundant muscle does atrophy over time. So let’s apply what we’ve discussed to some case presentations. These are two patients that I have recently cared for. One is an adult and one is a child. So the first case is a 26 year-old male. He has a history of bony dysplasia and had orbit surgery to his right orbit. He had an ex-op tropia before the orbit surgery. We hoped orbit surgery would correct the strabismus but it didn’t. He ended up with an intermittent exotropia of 20 and — which was 10. A convergence with more exotropia at near. No torsion. Often had control but late in the day he got diplopia. He works at a computer. The last few hours of his workday were very difficult for him because he had diplopia. His near and distance deviation did not equalize after a 30 minute patch test. This is an important detail. I covered his left eye or his right eye for 30 minutes and then immediately on uncovering, repeated my alternate cover test to see if the distance deviation of 20 would grow to match that 30 of near after the 30-minute occlusion test. If it did, I could operate on 30 prism diopters of exotropia but it didn’t. I can’t operate for this full 30 at near. I could end up giving him an esotropia in the distance and that’s worse than what he is experiencing now. I decided to operate for the exotropia of 20 and hypotropia on the right. And normally it’s his right eye that goes out. He is nervous about bilateral surgery and we decided we were going to proceed with lateral rectus recession and medial plication with vertical transposition of those horizontal rectus muscles. How much. I went to the table and looked at mono-ocular surgery tables and circled the 20 prism diopters lateral rectus dissection and medial rectus plication. Postop week one, he had a small exophoria that was close to even in the distance and near. The vertical was gone after the half tendon width transposition of both muscles. He was comfortable. His eye was red but he was comfortable and the diplopia later in the day, even after a week has already resolved. Case two. We have a 4-year-old. She has an alternating exotropia in the distance and near. Intermittent but it manifests most of the time. The angle is 30 to 40 prism diopters with alternate cover. Her parents prefer unilateral procedure and even though her right eye is out in this photograph, typically it’s the left eye that manifests and she had mild amblyopia on the left, 20/30 rather than 20/20. We’re still in the middle of patches but they wanted to proceed with surgery. I, again, looked at the table for monocular surgery for exotropia. And I’m going to do a lateral rectus resection and medial rectus plication. And before I tell you the outcomes, I want to just pause for our last poll question. What surgery would you perform? You know what I did. I’m curious, what all of you would do. Bilateral lateral rectus recession. Bilateral medial rectus resection. Bilateral medial rectus plication. Or unilateral lateral rectus recession and medial rectus plication. Okay. So I have some believers in the crowd. Many of you, 66 percent are joining me with unilateral surgery. 11 percent would go with a medial rectus plication bilaterally as well. I did a lateral rectus recession of 7.5 mm for the 40 prism diopters. She was 35 to 40 prism diopters and a medial rectus plication of 5.5 mm for 35 prism diopters. Sometimes I do that, one measurement from one line and one from the other if patients vary a lot and I’m concerned about overcorrecting them. And one week later she had a small Esotropia, exactly what we want. And postop month two she was orthophoric. So that’s the conclusion of the presentation I have prepared. I’m looking forward to answering questions in a moment. I just wanted to pause and thank you all. It’s been a real honor to give this lecture today. I think I mentioned it’s my first Cybersight lecture ever. This is my gmail address. I would love to hear how your plication surgeries go. Or talk about planning. Feel free to reach out. The audience today has had registered attendees from 87 different countries. I think it’s more than 87 because this list is everyone who was registered Monday morning and I think a lot of people registered since Monday morning. I wanted to recognize all of the different places that we’re gathering from. It’s an honor to be a part of this global community. Now I’m going to look at your questions. A lot of these questions are great. We went over many of them during the discussion. Are muscle plication and muscle tuck interchangeable? I briefly touched on that. I don’t think they are. I don’t think there’s enough data to support that a tuck for a rectus muscle will work as well as a plication. For a superior oblique, different story. But for a rectus muscle, I would advocate plication is equal to resection. But not tuck. And tuck would be muscle to muscle. Plication is muscle to sclera. Can you do a resection and a plication on a blind eye to maximize the resection? I’ve never done that. And I think doing the resection would kind of, it would undo your advantage of preserving the ciliary arteries. A blind eye that is at risk for phthisis is a great eye to do a plication on because you’re preserving that circulation in an eye that is at risk for ischemia. But, I would just do a maximal plication and see where you land. So we talked about my preferred suturing technique. Thank you, these questions are great. There are many. Do I have any adjustment — we talked about whether or not I changed the surgical dose table. I don’t. Some people for how many millimeters to do the plication instead of the resection will add a half millimeter to each muscle. Which suture is better? I use 6/0 Vicryl. You can use 5/0 Vicryl or any dissolvable suture. I don’t think you need the 5/0. It’s thicker. It will cause more inflammation as patients are recovering and more redness and itchiness if they have a reaction. I would use a 6/0 if you have access to a 6/0 dissolvable suture. It’s plenty strong. Most importantly to use a spatulated needle. In my videos, you see an S14 needle. Many colleagues before an S29 needle. S29 cuts a little bit better. But I work with residents on many of my cases so I prefer the S14. I think it’s a little bit easier to handle if you’re inexperienced. How long is the procedure reversible? We talked about that. To be safe I would say three days. But sometimes a week. Can you plicate again after you’ve undone a plication? Yes. You definitely can. You can plicate again. You’re going to have to judge the tissue on the day that you undo the plication to see if it really can take another procedure. It might be swollen. You don’t want to encourage too much bleeding or scarring or swelling. You may need to undo it, let the patient heal and try a plication again another time. If you’re still, you know, in operating room conditions and the tissue doesn’t look friable or swollen, you probably could change it the same day. But you’ll still need to cut all of that Vicryl out and place it fresh because you won’t have your needles anymore unless you placed it on adjustable. And then, let’s see, we talked about the cosmetic concern for the bulge or the lump. I, in five years, have had one patient that was really upset about the bump. And I talked her through it. I constantly reassured her that it was getting smaller. I took serial photos for her every week to show her it was getting smaller. She just needed a lot of reassurance. And one day she was happy. It took about two months. And I do plications in lieu of recessions for all of my patients except the one patient with a muscle dystrophy where I had to do a biopsy of his muscle in the last five years. Do I recommend mini plication for rectus muscles? In full transparency, I have never done a mini plication. But it was a part of my learning and preparing for this lecture and I do intend to try it. For small deviations, like 9 prism diopters or less, I think it’s a great option. If you’re in the operating room anyway or you want to try to do it under local in the office, for small deviations I sometimes will rely on Botox and bupivacaine injections. This is another great tool when you’re trying to just do some finishing touches on a surgery that was mostly successful but they have a small residual deviation or they have a small deviation to begin with but a lot of symptoms. Does the folded muscle increase the risk of Dellen. It can temporarily increase the risk of Dellen. It doesn’t take six to eight weeks for Dellen to resolve. But you can find in the first week or two the vision is down. If you prepare patients for that, it’s going to be swollen. The vision will be blurry. You may tear a lot. They tolerate it. Would I prefer limbal incisions to allow some conjunctival resection. That’s an interesting question. I don’t, I do fornix incisions whenever possible. In older patients when I’m concerned that the fornix incision will tear or in a patient who had radiation and I’m concerned that the conjunctiva is too friable for a fornix incision, then I do a modified Swan. I start a fornix incision and extend it anterior to the insertion. I really like sparing as many vessels as possible. I don’t think that I’ve ever found a clinical benefit from conjunctival resection. I try to keep the conjunctiva loose because in my hands, it’s the muscle surgery that gives me control of my patient outcomes and adding in a conjunctival resection I think would make it more unpredictable for me. How about, let’s see, how about sliding shave extra ocular muscle translocation with plication. I think you mean if you’re doing an adjustable, can you alts adjust the transposition, if you’re doing a vertical transposition. You can. You have to adjust the muscle plication and the transposition simultaneously. So basically, you can transpose the muscle as many millimeters as you’re plicating. If you plicate 5 mm, you can transpose up to 5 mm. Then you can adjust that on an adjustable technique. And then there was a question, I did a transposition with plication, who did I do it on? It was an adult who had a small vertical as well. So while I was correcting the horizontal strabismus, I did half tendon width vertical transpositions. What about V pattern or A pattern? You can do plications with V patterns and A patterns. You would move the muscles in the direction that you would move them if you were recessing and resecting. It would be the same direction to correct the V and the A pattern. It’s just that instead of resecting the muscle and physically moving it up or moving it down, you’re just plicating it. You’re putting your suture in the muscle and moving it to the insertion point that you want on the sclera. Follow the spiral of telo. There will be a sideways fold, oblique fold to the muscle when you plicate but that’s okay. It’s stable. So what type of suture? We talked about this already, I think I answered your question. But I would just use anything that dissolves after a couple of months. We want the tension to be maintained for a couple of months which is why I use Vicryl. I would wouldn’t use plain gut. If you don’t have access to something like that, you could use permanent suture. Just if the patient has a reaction later, you can also remove the suture after a couple of months of healing. Can I please repeat the steps of suturing for plication? Yes. What you do is, this is my little model here. I don’t know if you mean suturing the muscle or suturing the sclera. But in the Ken Wright technique, the first one I showed you. You do the partial thickness, center to edge and a locking bite avoiding the vessels. Then you do the same thing on the other side, partial thickness and a locking bite avoiding the vessels. For the Monte Delmonte technique, which I like, it’s new to me but I thought it was great and the outcome is great. You start the same. Partial thickness through the muscle center to edge and then you double back and go edge to center through the same holes. And it’s partial thickness but it’s more superficial. You’re going really just skimming the superficial layer underneath the ciliary arteries. You’re doing that to set yourself up to do a full thickness through that original hole again. You turn the needle around, go through the original hole, and the needle comes out underneath the muscle full thickness. You have a loop here you pull it through to lock it. You just pull back on your suture and then pull forward so you don’t get an air knot. Then you go in the other direction, partial thickness, center to edge. Back through the same hole. Very superficial. Just underneath the vessels. Edge to center hole. And then the full thickness. You leave a little loop here like this and do full thickness through the original hole. Down below and pull it through a loop to lock it. Then for your sclera, if that’s what you were asking, you can do cross swords in the center. Partial thickness scleral tunnels. Or you can do partial thickness without cross swords but you have to be careful to avoid the vessels. Like go in here and come out over here. Then to tie the muscle, you pull, I hope this is answering your question, you pull the Vicryl up towards the ceiling. This is the only sometime in strabismus surgery that we’re pulling suture up to the ceiling. Normally that is unnecessary tension and you will break the suture and lose the muscle and everybody is going to be unhappy. But for plication you have to gently pull up away from the eye towards the ceiling. Then you pull towards the limbus parallel, much like you’re used to. Normally when you recess or resect a muscle, you’re pulling in the plane towards the limbus. But for plication it’s up and then towards the limbus and up towards the limbus. Once or twice and sometimes three times depending on how much the muscle is willing to move to get it to lay flat. And then you finish tying your knots. Mode of anesthesia. The mode of anesthesia for this procedure is up to you. It’s really the same as what you would do for a resection or recession. I favor generally anesthesia but I have done these procedures under local anesthesia. I had an adult patient — I wouldn’t do local anesthesia for a child. But I had an adult patient with multiple medical issues who was not comfortable with general anesthesia. I put, I think 5 or 6ccs of mar can sub T through the fornix incision. And let that sit for a few minutes. And then she was totally comfortable during the plication. I put some tetracaine on the cornea before I made the conjunctival incision. She did great. Complications are similar to strabismus surgery. You’re reducing the risk of anterior segment ischemia but not completely eliminating it. It’s still a risk you have to discuss with your patients ahead of time. But you’re significantly reducing that risk. Risk of infection, inflammation, scarring, bleeding, diplopia in the opposite direction from over correction. All of those are unchanged risk, the same as other strabismus procedures. Okay. Do I feel comfortable operating on three muscles at once when I do a plication for one of them? Yes. I do. I don’t typically interrupt two ciliary arteries at the same time. Like I’m trying to think of a situation where I would do two recessions and a plication. That is pretty rare. But I would. Yes, when I do transpositions, like for a sixth nerve palsy, I also use vessel sparing procedure. I tend to favor sparing vessels whenever possible. But yes, if you’re only interrupting two circulation, two muscle circulations, then yes, I would do a plication as a third procedure at the same time. And then I have time for one more question. I’m sorry, these are great questions. I would love to be able to get to them all. What is the maximum millimeter I can plicate? That’s a great question. I think it depends on the surgeon and the patient and the orbit and how far back you can get. When I do, again, surgery for sixth nerve palsies, I plicate the lateral rectus muscle maximum and do a modified Nishita (ph.) procedure. And then I recess the contralateral medial rectus and sometimes the medial rectus on the same eye. How much do I plicate the lateral? I do maximum. Whatever I can get. In most patients, it’s really hard to get more than 7 or 8 mm to plicate and fold nicely for you. But if you feel like you can get far back, don’t forget you also don’t want to get the inferior oblique involved when you start getting too far back on the lateral rectus. But I think you can get as much as you feel comfortable being able to fold and seeing the vessels well where you’re placing your needle and you’ll have control that far back in the orbit. Be careful about that. I said only one more questions but I want to scroll through quickly. There is no minimum age. I think any age is okay. And I don’t think kids rub their eyes more because of the lump. I actually think kids do better with plications because their eyes don’t hurt. So they’re willing to move their eyes in full pretty much right away after surgery with plications. And how I manage pain during adjustables? I use topical lidocaine jelly. It’s a 2 percent formulation. I put tetracaine on first, I clean the area, and then I put sterile lidocaine jelly on. And I make sure to set a timer and leave it there for five minutes before I start poking the eye. Okay. I think that’s most of the questions. Again, it’s been a real pleasure. Thank you very much.

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