This video demonstrates a superior oblique tendon tuck and an inferior oblique recession surgery in a 6-year-old with superior oblique paresis. Dr. Marmor explains all the steps during the surgery and answers the questions at the end.
Surgery location: on-board the Orbis Flying Eye Hospital in Chittagong, Bangladesh
Surgeon: Dr. Maury A. Marmor
DR MARMOR: This patient is a 6-year-old who has a right superior oblique paresis. And he has a large vertical deviation in primary position of about 25 prism diopters. And so we’re going to do some investigation first on whether the superior oblique in the right eye has a normal tone or whether it may be lax. So he has inferior oblique overaction, and we’ll be recessing the inferior oblique, but for the amount of deviation in primary position, that wouldn’t be enough to take care of the vertical deviation. So we would need to add a second muscle. The second muscle would be a tuck of the superior oblique, if it’s in fact lax, or it could be recession of the inferior rectus on the other side. So we’re gonna determine that with forced duction testing.
>> And can you just again summarize — I know you’ve been talking about it all week. Tell us why you do forced ductions, and how you do them. Very slowly just tell us: What are the purpose of forced ductions, and what are you testing?
DR MARMOR: In this particular case, there’s a risk, if you do a tuck on a superior oblique that’s of a normal tone that you’ll create a Brown syndrome. And so it’s a better idea to tuck the superior oblique in cases where it’s lax. And then you’re returning it to normal tone, as opposed to taking a superior oblique with normal tone and creating a restriction.
>> Does everyone know what Brown syndrome is? What is Brown syndrome? So I remember — the way I remember it, and I’m not a strabismus doctor, so I have to make it simple for me — I always remember Brown BREAD. So Brown is restriction and AD-duction. B for Brown, RE is restriction, and then AD is AD-duction. And, sir, what are you finding on your test so far?
DR MARMOR: So I’m grabbing the limbus nasal and temporal. I’m retropulsing the eye a little bit, adducting it, and then as I roll the eye up and down, you can kind of see it roll. And you can feel… I can feel it, like it’s rolling over the band. That band is the tight superior oblique tendon. The normal superior oblique tendon. In this eye… When I do that… And I go into this position… I don’t have that feeling at all. The other thing you can look at is… With a speculum in… And how far up you can turn it — how easily you can turn the eye up. So I can easily bury the cornea. Easily. And here, I’m just about at the limit of where I can move the eye up. I can easily bury the cornea under the speculum. So I do think we’re dealing with laxity. We’re going to investigate that further, by looking at the superior oblique directly. Can we have the corneal protectors?
>> So now that you’ve done the forced duction test, how does this affect your surgical planning, and what procedure are you thinking about in your head?
DR MARMOR: So I believe that we’ll find the superior oblique is lax, when we look at it. So I’m going to plan a tuck. So the amount of the tuck is determined by trying to restore the close to normal tone. So I’ll put in… If we’re doing a tuck, I’ll put in the tuck sutures, tie it temporarily, and then check forced ductions again. See if I can restore it to a more normal function. I want to make sure that intraoperatively, I’m not creating any restriction. One more time on the traction test. So I’m first pushing the eye down. Retropulsing the eye. Adduction. And then as I roll it up over, you can see it’s rolling over the tendon. In this eye… Push the eye down. There’s no feeling like that. We’re gonna turn the eye down and in. Okay. Let’s look for the superior rectus. Can we find it? Can we see it? Rotate the eye a little bit so we can see it.
>> You’re gonna be using the vasculature to find the rectus muscles?
DR MARMOR: Yes. First I’m looking to identify the position of my incision by looking for the ciliary vessels.
>> And I notice you first like to open the conjunctiva before going deeper into the Tenon’s. Is that correct?
DR MARMOR: That’s correct. Okay. A small hook. So I’m going to just extend this incision a little bit. If you look over here, you can see the striations of the superior oblique fibers.
>> Yes, sir.
DR MARMOR: And so this is the area of the superior oblique. And so sometimes it’s easier to hook it from the front side. And sometimes easier from the back side. And I’m checking back here for… Looking for any more fibers. I don’t see any more fibers over here. So I’m going to try about, I would say, a tuck of about… It doesn’t look very lax on the hook, although it felt lax on the duction testing. So I’m going to take a Mersilene suture.
>> And can you tell us what Mersilene is, and what size?
DR MARMOR: Mersilene is a polyester suture. Can I have the caliper, please? Set the caliper on 4, please.
>> And, again, you like to have the needle pass through the belly of the muscle and then do a single locking suture?
DR MARMOR: Yes. So I do it like a plication. I like to secure the muscle and make sure it doesn’t slip forward, when I make the tuck.
>> So this was very similar to the technique we saw you demonstrate with the strabismus surgery.
DR MARMOR: Yes, with the rectus muscle. Similar.
>> What’s gonna be different with your next move?
DR MARMOR: Well, I’m not going to make a scleral pass here. I’m going to pass it through the tendon over here. Near the insertion. I’m gonna tie just a single throw, like this. And I’m just gonna tie a loop, like this. Just a loop. So it’s like a slipknot. And then we’re gonna take this out. And then we’ll take everything. Take this out. And have a look and see if we’ve changed the forced ductions. So I see a difference already in how much I can bury the cornea. So some people go by creating enough limitations so that the lower limbus is even with the line between the canthi. And I feel that that is too much restriction.
DR MARMOR: And I just like to have it — improved forced duction. To a point where I can feel the muscle. And get some improvement in the resistance. So I have that.
>> So by doing that slipknot, if you needed to go back and adjust, you had that opportunity, right?
DR MARMOR: Yes. So what I can do here is just try to complete it by cutting the end and pulling the knot through and making that the second throw.
>> Right. But do you feel like you’re gonna need to adjust this? Or you feel like this is the right…
DR MARMOR: No, I’m happy with this.
>> So you’re gonna finish this knot, correct?
DR MARMOR: Yes.
>> So you use the forced ductions not only to make the diagnosis, but to titrate the treatment?
DR MARMOR: That’s correct.
>> So now you’re gonna undo the slipknot and finish by an instrument tie. What tie do you do?
DR MARMOR: This was a 1-1-1, because there wasn’t a lot of tension. And in case I needed to undo it, it’s harder to undo the two throws on the first knot.
>> What is the suture you’re using? What is the material and what is the gauge of needle?
DR MARMOR: This is 5-0 polyester. And I like 5-0 polyester, or even better, 6-0 polyester, if it’s available.
>> Okay. What other points would you like to make with regards to teaching or follow-up? Do you see this is an immediate effect? Or sometimes it takes a few days or weeks?
DR MARMOR: There’s an immediate effect on this. So you can see the difference right away. And, in fact, if you overcorrect, you see that postoperative Brown syndrome on the first day. So now we’re gonna do the right inferior oblique. Because this is a large deviation, and we knew that two muscles were required. It just wasn’t clear whether the second muscle was gonna be the inferior rectus on the left. All right. So here’s lateral rectus. Here’s inferior rectus. I make my incision here. All right. Do you have a small hook, please? The next suture will be the 5-0 silk. So now I’m hooking the lateral rectus muscle. And now I’m gonna pass a traction suture. So the superior incision is coming into play. We’ll have to close both incisions, obviously.
>> And can you tell us why you’re making this pass with the suture?
DR MARMOR: This is a traction suture.
>> Is this exposure? For what reason?
DR MARMOR: This is for exposure. You’ll see in a moment. So I’m going to protect the cornea. I’m going to turn the eye up and in. And I’m gonna clamp the suture to the drapes. So now I have the eye in an adducted position. We’re gonna look in the infratemporal quadrant for the inferior oblique muscle. Okay. So the Graefe hook goes in the infratemporal quadrant. Lift up there, please. Hold this, please. And this goes under the lateral rectus muscle. Hold this, please. Okay. Let me reposition this one. Okay. And a small hook. And a scleral depressor. Can you see into the hole?
>> Yes, we have a good view.
DR MARMOR: So here is the inferior oblique muscle. You can see a pink band over there. Then after the muscle you see the white. That’s the Tenon’s. And then you have a very good view here of the vortex vein. Can you see the vortex vein?
>> We can see it, yes, sir. Can you go back through those three landmarks again? So start from the beginning.
DR MARMOR: Okay. Inferior oblique muscle. Tenon’s. And vortex vein. So we want to make sure we get the whole muscle. And we don’t want to hook the vortex vein. So I want to make my pass of my hook beyond the edge of the muscle into the Tenon’s, and then I’m going to go out with the point towards the ear and come around. You can take your two hooks out now. Okay. So now I’m gonna pass the hook to myself. So now I have the muscle on the hook, but I have a little bit more. I have a little bit of Tenon’s here. And what I want to do is I want to make sure I have the muscle, and nothing more than the muscle. So I’m going to start unloading the hook. And if I think I have a lot of Tenon’s or fat, I can suspend it and play with the hook to try to position the hook right at the edge of the muscle, which I think you can see nicely there. And then, when I feel I’m close enough, then I ask my assistant to make a small cut. A small cut very close to the tip of the hook. Small cut. Okay? And then what I’ll do is I’ll hold this open, and ask my assistant to put a Green hook through. The same direction as my hook. Okay. And then I will take another Green hook. And this goes in the same hole. In the opposite direction. And with the handle down towards the ear. Now, hold this, please. And then another hook, a Stevens hook, goes under the lateral rectus muscle. And hold this. And pull them both out. So now I’m holding the inferior oblique muscle. Scissor, please. And I’m gonna cut this intramuscular septum very close to the muscle. So now I’m separating the attachment between the lateral rectus muscle and the inferior oblique muscle. And then as the last thing, I’m just gonna go in and disinsert the inferior oblique muscle.
>> Can you contrast both anatomically and the surgery between the superior oblique and inferior oblique, about which one retracts for slip muscles, how you reapproximate the tissue, et cetera?
DR MARMOR: The inferior oblique muscle, and likewise the superior oblique muscle, since they don’t have origins — they have attachments — they’re not going to disappear. Of all the muscles, the muscle most likely to be lost or slipped, if you lose control, it would be the medial rectus muscle. The inferior oblique, as you can see, when you cut it, it just stays there. So some people preplace the suture, but it’s not necessary. You can just cut it off. To me, I find it a little bit easier to pass the suture after. So this is 6-0 vicryl on an S28 needle, which is a half circle needle. So it’s ideal for making smaller passes in the sclera. We use S29, which is a 3/8 circle needle. We use that when we’re making longer passes, such as working with a rectus muscle. The inferior oblique is a tubular muscle. And we don’t really want it to be spread out. We want it to be bunched up in its reattachment. I’m gonna pull it ’til about half the suture comes through. And I’m gonna take a lock bite on this side. Place a lock bite on this side. You can see that the muscle is narrow. You don’t want it wide. Because a wide reattachment of the inferior oblique muscle can cause antielevation syndrome. Deficiency of elevation in AB-duction. So now the muscle is secure, the next step is I’m going to remove the traction suture. And I’m gonna hook the inferior rectus muscle. Reattachment of the inferior oblique is done by landmark, based on distance from the inferior rectus insertion. So my preferred recession is 4 millimeters posterior to the temporal pole of the inferior rectus.
>> And can you just talk about, again — that’s a very important teaching point. A, what landmark you use, and B, how you determine how far to place the new attachment site.
DR MARMOR: So my preference is to, when I do a recession, is to place it 4 millimeters back from the temporal pole. This is the temporal pole, right here, of the inferior rectus muscle. You can see it and you can see me strumming it right there. So I want to be 4 millimeters straight back from there. So here’s another landmark. There’s the vortex vein right there. So I’m just gonna take a small bite in sclera right here. 4 millimeters back. It doesn’t have to be very deep or very long. And again, I like the muscle close together. So I’m gonna make the second pass very close to the first one. And I’m avoiding the intrascleral portion of the vortex vein over there. You can see there’s an intrascleral portion of the vortex vein there. So I’m not going near there. I find it easier to pass the sutures with my left hand, even though I’m right-handed. So that’s a little bit of a challenge there. So I just switched — for the left eye, I find it easier to use the right hand. Okay. And take out the retractor. And then put it right back in. Below the conjunctiva. And so we don’t want to pull up any Tenon’s with the muscle. So if there’s any question about it, you can push it away. And then pull it back up again. And this, as you can see, there’s no tendency for it to slip at all. So I’m tying this with a simple 1-1-1 knot. So now I’ll just be closing the conjunctiva. So any questions?
>> So actually, I have two questions. The first one is: You’re using 5-0 polyester in tucking the superior oblique. Is there any option to use also 6-0 vicryl?
DR MARMOR: The question was: I’m using 5-0 polyester. Is it possible to use 6-0 vicryl? It’s not the gauge that’s important. On a superior oblique tuck, what’s important is to use a non-absorbable suture. Non-absorbable suture possibilities would be prolene, polypropylene, or polyester. Or Mersilene. So 5-0 is okay. 6-0 is okay. I like the polyester, because it’s soft. As opposed to the polypropylene, which is a little bit stiff. And possibly the ends could work their way through the conjunctiva. So I prefer the Mersilene. Or polyester.
>> Another question is: Is it okay to use crossed swords technique in inferior oblique attachment to the sclera?
DR MARMOR: It’s okay to use it. It’s fine to use it. But it’s not necessary. So crossed swords technique is important when you want to create friction so that the muscle doesn’t slip. In the case of this inferior oblique muscle, you can see the muscle wasn’t under any tension, so it’s okay to use parallel passes. And that’s beneficial, because in this particular case, I don’t want the muscle to be spread out.
>> So you cut the inferior oblique, and because it’s not — you’re not worried about a slip muscle, you don’t preplace the suture. Is there anything that you would recommend? Or can you preplace the suture before cutting or disinserting the inferior oblique?
DR MARMOR: You can preplace the suture, but I don’t find it necessary. I find it actually difficult to preplace the suture. It’s very deep in the hole. You need a very good assistant and good exposure. So for me, I would say there’s no reason to preplace the suture in the inferior oblique, given that, when you cut it off, it doesn’t go anywhere. It doesn’t generally bleed. Sometimes it does, but generally, as you can see in this case, you don’t see bleeding.
>> Okay. Thank you so much.
DR MARMOR: Thank you.