Lecture: Advanced Techniques/Management of Difficult Strabismus Cases

Dr. Adams discusses the following topics in this presentation:

  • Adjustable sutures
  • Surgical management of cranial nerve palsies
  • Use of amniotic membrane grafting in complex strabismus

Lecturer: Dr. Gillian Adams, Moorfields Eye Hospital, London


(To translate please select your language to the right of this page)

DR ADAMS: What I want to talk to you today about is adjustable sutures. I want to talk about management of cranial nerve palsies. And then I want to talk about the use of amniotic membrane grafting in complex strabismus. So these are the three questions that we’re going to start with, and that we hope we’ll be able to answer at the end. Is adjustable suture surgery suitable for all types of squint surgery? Yes or no? 6th nerve palsy with no abduction beyond the midline is best managed with a recess/resect procedure? Yes or no? And adhesive strabismus is best managed with another operation on the scarred muscle? So as you saw yesterday, the adjustable suture surgery is done in two stages. The first with the patient asleep, and the second with the patient awake. Now, if you want to do it with the patient all awake, that is certainly possible, but most patients, certainly in the UK, won’t tolerate that, and most of them would have to be done with an anesthetic block. And when you put an anesthetic block in, you paralyze the muscles, so you can’t do an adjustable. And so what we did was we did the patient yesterday under general anesthetic, and we had used lidocaine gel, and the anesthetist very kindly gave him a very short-acting opiate, when he was starting to feel a bit uncomfortable. So the reasons that we use adjustable sutures are when the patient is at risk of double vision, if we either overcorrect or undercorrect, and so we want to be able to fine tune the alignment. We use it when we’re doing revision surgery. In other words, when the patient’s had surgery before. So, for example, if you’ve had surgery as a child, and you’re talking about an adult, the muscle may have moved, or what you get told is not what’s actually being done. It’s very useful in thyroid eye disease. And if you’ve got a very small squint, where you really, really can’t afford to overdo it, so you need to use adjustables, and if you’re aiming to restore binocular single vision. The people you shouldn’t do it on are patients who are very scared and very frightened, because they will not tolerate the adjustment. Avoid very tight thyroid muscles, because the muscle can pull off the stitch, because it’s so tight. And you actually — when you release the muscle, it goes so far back, you can’t pull it up, because it’s just so tight. So they are better fixed. And very scarred sclera. So two weeks ago, I took a patient to theater who had had multiple surgery for Duane syndrome, and we advanced one muscle, and when I went to look at the lateral rectus, I took the lateral rectus off, and all that we saw was black uveal tissue. So there was no way, despite my plan to do an adjustable, that I was going to do that, faced with that very scarred sclera or very thin sclera. If the muscles are lost, there’s a running rule that once you’ve lost a muscle once, you will lose it again. So it’s better to fix that, and fix it with a very thick stitch or a non-dissolving stitch, rather than an adjustable suture. And I wouldn’t recommend doing superior or inferior oblique surgery on an adjustable suture. Inferior, because it takes up to 3 months for the operation to work anyway, so the adjustment won’t be very helpful. And the superior, because most of the time, the muscle is very fragile, and if you pull, adjust on it, it could very well come off the stitch. Now, we do the adjustment the same day. Usually approximately 2 hours after surgery. I have in the past done it the next day. And you will see some people tell you that they can do it at one week. All I can tell you is: Doing it at 24 hours is very sticky. And we’ve all had to take lost muscles back to theater at 2 days. And it’s not easy. So if you can, I would do it a couple of hours after surgery. So long as your patient’s awake, and the muscle moves very easily. It’s easier to advance muscle than to push it back. So the best technique is to overrecess and then pull forward. If you’re going to do a resection, the best way to do that is to do a bigger resection than you would normally need, and recess it, and then if you’ve done too much, you can pull it forwards. But as I say, setting muscle back is much more difficult. So what you saw yesterday: You would use a double-armed 6-0 vicryl. So you do two passes through the center. Full thickness, partial thickness to each end, and you lock it. You take the muscle off the eyeball. And you do this double diamond suture that you saw Dr. Phan and myself doing yesterday. Make sure you’ve got all the muscle. And then put a bow loop on it, and then you can pull on this, as you saw. So we put pressure at the insertion, pulled along, and the muscle just comes pulling up those tracks. Now, a few tips and tricks. Don’t put ointment in at the end of the operation. Otherwise, you won’t be able to get a grip on your stitches. Put lots of anesthetic drops in, but what you saw we were using — we used lidocaine gel. And if you can get that, you just need to put one application of that in, and it saves the time of having to put it in. You need to do your cover test before you adjust, because you need to know what to do. And you need to do it for near and you need to do it for distance, and on occasions, you need to do it on side gaze, to make sure you haven’t overcorrected on side gaze. Then you can decide whether you need to adjust or whether you just tie off. And what you saw we did yesterday was we pulled the conjunctiva over the knot, so if we had not had to adjust, we could have tied it down, and just pulled the conjunctiva forward. But because we had to adjust, we had to put additional conjunctival sutures in. And as you saw yesterday, you keep doing it until you get the correct alignment that you want. So if we start looking at cranial nerve palsies, our goals are to give the largest area of single vision, and that’s usually straight ahead and looking down. And you want to reduce the head postures that some people have, and you want to improve their aesthetic alignment. So if you look at — this is a lady with a 3rd nerve palsy. She’s got a ptosis, divergent eye, but in fact she’s slightly hypertropic. It’s usually hypotropic. And hers was secondary to a tumor, a meningioma. And so the eye is down and out. And there’s a ptosis. They may have the pupil involved. And if your eyelid’s right down, you don’t get double vision. Otherwise, you get a face turn to the good side. And the important thing to remember is: If it’s acquired traumatically, so if they’ve come off a motorbike at a road traffic accident, they may have lost their ability to fuse. So when you manage them, you need to distinguish between partial and complete palsies. So if they’ve got a divergent squint with good adduction, you know, they reduce, but it’s reasonable, then a recess/resect procedure, possibly combined with a transposition, is the way to go. If they’ve simply got height, then you can manage — if it’s a hypotropia, you manage that with a Knapp, or if it’s got height, hypertropia, which is uncommon but sometimes happens, then you can manage that with an inverse Knapp, where you take things down. And remember, if they’ve had surgery before, you can only do the two muscles if they’re an adult, but there’s the risk of anterior segment ischemia. And you correct the ptosis after you’ve corrected the divergence and the height. Now, then you’ve got the problem of the 3rd nerve palsy with no adduction. And they’re a much bigger challenge. So these are the operations that have been suggested. A recess/resect procedure, with traction stitches. And by traction stitches, I mean putting stitches in at the limbus, quite deep, and pulling the eye inward, and putting the stitches into the skin of the nose, for about 4 weeks, just to hold the eye, so that it sets in adduction. Then you can do a superior oblique tenotomy, which is useful in the down eye. The slightly exotropic eye. More commonly with the superior oblique, you transpose it nasally to the medial rectus border. The only thing I would say is it lasts two weeks, so it’s never, in my hands, a great operation. You can take — so we saw a transposition today for a 6th. You can do the transposition the other way, so taking them nasally, rather than temporally. But you’ve got to resect about 4 or 5 millimeters, because obviously as you take them nasally, they loosen. So you’ve got to rotate them sideways and tighten them up. And there’s an operation that’s reasonably new, whereby you take the lateral rectus, you split it in 2, and you take the strips under the superior and lateral rectus, inferior rectus muscles, take it round to the medial — now, the only problem is that the people who devised it in Boston — even they find that they sometimes can’t do it, if the lateral is tight. And they’ve had choroidal effusions, and their complication rate is somewhere between 25% and 30% in their published paper. So it sounds like a great operation. It may be the only operation you can do, if they’ve had lots of surgery before. But it isn’t… It has got some risks associated with it. And then what I’m going to talk to you about is the way we currently have decided to manage them at our institution, which is periosteal fixation with traction stitches. So what we do is we do periosteal anchoring, and I do this with one of my orbital colleagues. We have about 125 ophthalmic consultants. So I have about 4 or 5 orbital colleagues. So I’m able to get them to give me a hand. So they approach this retrocaruncularly on the medial side, get down to the lacrimal fossa, and to the crest, and they put a double-armed 5-0 Ethibond into the periosteum, above the crest. I then thread it through, to the medial rectus insertion. And then we pull it backwards into the nose again. At the same time, we take off the lateral rectus, and we put it on the orbital wall. So we completely detach the lateral and we pull the medial over. And then we put the skin traction stitches in. I don’t normally put them in — they’re usually much shorter than that — and they are 5-0 prolene, which go fairly deep through the limbus, and then come out top and bottom, and we tie them over tarsorrhaphy bolstering. Now, if you don’t have tarsorrhaphy bolstering, we use butterfly tubing, and we just tie them over that for 4 to 6 weeks, and then it’s very easy to release, because you cut onto the suture, onto the bolster, so you’re not touching the skin, and then just pull it through. So, to give you an example, these are two cases that — this is a little boy, and this is what he looks like sometime after the operation. We’ve taken the traction stitches out here. You’ll see the ptosis still remains. And this is a gentleman who has bilateral 3rd nerve palsies, and both eyes were like this. So we fixed this eye so that it was lined up central, and then my plastics colleague, as you can see, lifted his lid. So we’ve left this side. Because he really only needs one eye central. But he couldn’t adduct either eye, so he couldn’t watch TV, and he only could see people like that. So we fixed just the one eye. And you can see here — this was him soon after we took the traction stitches out. So you can see just the little mark. But as you can see, this heals really very quickly. So if you do the retrocaruncular approach to the medial rectus, there’s no skin marks on — there’s no DCR-type approach mark. And the skin from the traction stitches heals very quickly. That’s why I would suggest using prolene. It doesn’t scar. Leave it in for 4 weeks. And you want them about 20/25 esotropic. Postoperatively. Because when you take the stitches out, it will come backwards. And the final thing is that when we first started doing this, we just started to loosen the lateral rectus, but long-term — I’m talking if you want more than five-year results — you have to be brave. You have to take the lateral rectus off. You have to put it onto the orbital wall, as well as fixing the medial. It sounds very interventional, but it is the only way to go. So I know that Dr. Wagner covered quite a lot of 4th nerve palsy, so I’m going to talk about the sort of different bits, because he very kindly told me what he was lecturing on. So I’m just going to remind you that you usually start with an inferior oblique weakening, and then you either do a tuck or a superior rectus recession. So I know that Dr. Wagner talked to you about inferior oblique, so I’m not going to do that. I’m going to talk to you about superior oblique tucks. You don’t often have to do these. They’re much more common for the congenital. It’s very unusual to have to do them for the acquired. I usually only do them for acquired when there is a tumor on the nerve or whether the neurosurgeons have damaged the 4th nerve, so it’s been transected. So you tuck temporally. Because obviously if you tuck nasally, it’s going to get caught up in your superior rectus. So you sweep the muscle temporally, and you can use a tendon tucker. But if you do that, the amount you tuck is double what you measure. And you’ve got to tack it, once you’ve tucked it, and you’ve got to use a non-absorbable suture, and then you’ve got to tack it onto the sclera. But the thing you’ve got to do — and you saw Dr. Phan doing this yesterday — was a traction test to make sure you haven’t given the patient a Brown’s because you’ve overtucked. So as a rough guide, if you’re doing a congenital, you can do anything up to 12, 14 millimeters of a tuck. If you’re doing a tuck on an adult, you probably only need to tuck 8 millimeters, max. If you do it properly. Plus the scleral fixation force. So it’s an operation which takes — doesn’t take that long. Except that if you haven’t quite got it right, you have to take the tuck down, and you have to keep doing your traction test. So if you’ve got an acquired 4th nerve palsy, apart from the tumor — that’s one. But if you’re just talking about what I call the road traffic accident one or the CVA one, you’re usually — first of all, wait. Because it may improve. First of all, start with an inferior oblique weakening procedure. You saw the recession yesterday. And that usually helps. And the other operations that you can do are a contralateral inferior rectus recession, an ipsilateral superior rectus recession, an ipsilateral inferior rectus resection — but as I say, the tuck is not normally needed unless it’s congenital or somebody’s cut the nerve or there’s a tumor on the nerve, like a schwannoma. So if there’s no torsion and it’s bilateral, just treat it as unilateral right and unilateral left. So you go through the list of operations I gave you on the first slide. But if there’s torsion, that’s a real barrier to fusion. So you need to do Harada-Ito procedures. So let’s look at how you measure torsion. And how do you know that there’s torsion there, and it’s important? You can measure it with a synoptophore or double Maddox rods. We use synoptophores. I don’t find, personally, fundus excyclotorsion very helpful. You can measure it on photography, but the problem is: If you’ve actually — when you do the photography, people put their head in sideways, so you may get tilt anyway. Now, 14 degrees of excyclotorsion means that it’s bilateral. It may be asymmetric. And it may be that you don’t see it very much on one side. But it’s bilateral, and you need to correct it bilaterally. So I’m not sure how often you do Harada-Itos, but they’re a lovely operation to do. So what you do is you split — you first of all put one traction stitch in, and pull the eye downward, and then you get your hook under the superior rectus. Now, the easy way to do this is to find the superior oblique. If you saw us operating today, you would see that we found the superior oblique. We found it yesterday. You find it on the nasal side. And you pull it under the superior rectus, to the temporal side. And then you put it up on your hooks, and then you split it — you put one stitch in the anterior half, and then you split it and cut it, and you take forward — so you split it and take forward this anterior portion to midway between the superior and lateral rectus. And I just eyeball it and then mark it with ink. I don’t actually measure 12 millimeters and then measure 6. I just look at it, put — and you know, when you’re cutting something in half — put the ink there, just anteriorize it there, and very often put a second stitch in, and it’s a very nice operation to do. Now, 6th nerve palsies — the important thing with a 6th nerve palsy, when managing it, is to differentiate between partial and complete. Because if you get that wrong, you’ll do the wrong operation. So you’ve got to — even in a squint like that, you can often abduct fully. But if you can’t get beyond the midline, you need a transposition, and if you can get beyond the midline — so if you can’t get further than that, you need a transposition. And if you can get all the way out, or most of the way out, or 75% of the way out, you need a big recess/resect procedure. Now, we use botulinum toxin to assess that temporarily. But the important thing is that you cannot do three muscles in an adult, or you get this, which is anterior segment ischemia, where you get folds in Descemet’s, the vision goes to count-fingers, and this was this lady one day postoperatively. And she had had surgery for two muscles, 22 years before she had further surgery, and then she got this. So you can’t do three muscles in an adult. You can do three muscles in a child, as you saw us doing this trip. But not in an adult. So you saw us doing a transposition today for a different reason. You saw us doing a transposition for Duane. And we take it round and we put the augmentation sutures on, and then later you may need — six months later you may need to do a faden procedure. Now, adhesive strabismus is where the muscles are very stuck down, the eye is very scarred, and it makes it very difficult to operate. Now, it is often vertical. As we spoke about yesterday, it can happen with a retinal detachment surgery, it can happen after inferior oblique surgery, it can happen after traumatic interventions, and it’s very difficult to fix. And so what we’ve tried to do is to think about doing — recessing the conjunctiva and filling the gap with amniotic membrane to prevent further adhesions of the conjunctiva and the subconjunctival tissue. So we use amniotic membrane, and we use it frozen. It comes from our tissue bank. And it’s obviously been checked for viruses and everything by the time we get it. We order it in advance, and we can get it up if we have to in a hurry. And we defrost it, and we use it, and it reduces adhesions, it prevents — reduces inflammation, and it stops the scarring if you use it as a barrier between the two split conjunctival and subconjunctival fibrotic areas. So what we do is we go and explore, and we divide up the adhesions. We do the squint surgery, we separate the scar tissue, and then we insert this amniotic membrane, and stitch it into place, and this is it. We often sometimes use traction stitches, and you can see that here, to hold the eye in position away from the scarring, and this is one patient, immediately after. This is day seven. Two weeks and four weeks. So it all goes away. You’re not left with a permanently scarred piece of tissue in the eye. And these are the more usual traction stitches that are put in with the prolene. So this is a girl who had had seven or eight operations on the vertical muscles, and this was her — she couldn’t move the eye at all. So we put… We did some surgery. We did traction stitches in. I put an amniotic membrane graft in. Now, she’s not perfect, but she is better than she was. So is adjustable suture surgery suitable for all types of patients? No. Because not all patients are going to tolerate it. They can be scared. They can be too young. A 6th nerve palsy with no abduction beyond the midline is best managed with what procedure? It’s best managed with a transposition, isn’t it? That you just saw. And then adhesive strabismus — is that best managed with an operation? Just another operation on the scarred muscle? No. Because you’ll just make more scarring. So you’ve got to cut away the adhesions, and that’s where amniotic membrane comes in.

June 7, 2017

Last Updated: October 31, 2022

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