During this highly-interactive live lecture, Dr. Neely answers all of your questions about pediatric ophthalmology and adult strabismus.
Lecturer: Dr. Daniel Neely, Pediatric Ophthalmologist and Professor of Ophthalmology | Indiana University School of Medicine, Indianapolis, USA
DR NEELY: Well, welcome! I’m Dr. Daniel Neely, your Cybersight webinar host for the day. And I appreciate everyone tuning in to our… This is our number 110 webinar for the year. Just about three years ago, we started with just a handful, and it’s pretty exciting to see that there’s been this much interest in these webinars. 110 webinars for the calendar year, this is the last one for 2019, and we have over 460 participants for today’s event. Today, a couple of housekeeping orders. I will be taking live questions. I have a few that have been submitted in advance. I will be answering live questions on pediatric ophthalmology and strabismus. Pretty much I think anything is fair game, so feel free to use the question and answer function to submit those. I’ll start off with the ones that were submitted ahead of time, just to get us rolling and get everyone on board. A couple other items. I am coming off one week of influenza, even though I had my flu shot. I apparently found another strain. So if I am a little bit rough at times, or if I am taking my cough drops, bear with me. I am also on trauma call for the hospital. So hopefully we get left alone there. But I have my cough drops. I have my coffee. We’re good. I will intermittently be switching back and forth between talking to you directly, and a few PowerPoint slides, and then also using the whiteboard feature. So there may be moments where it’s a couple seconds, as I transition from one screenshare to the other. So for starters, I will kick off with some of the previously submitted questions. And get the ball rolling here. So let me switch over to my… The few PowerPoint slides that I have. And again, this is pediatric ophthalmology and strabismus, and a question/answer session. I will stay here pretty much as long as we need to answer everyone’s questions. So we’ll just keep this rolling. Let me go back. I just went too far. The first question is from a doctor in Jordan. And this is an important question, because ROP is definitely becoming a crisis in areas with developing health care systems, as these babies start to live longer, or start to survive premature birth. And this question is pretty straightforward. What is the best laser wavelength for the treatment of retinopathy of prematurity? So laser is — even with Avastin, and these other anti-VEGF agents, laser is still pretty much the gold standard. I think it’s fair to say. And it’s pretty straightforward here. The 810 nanometer diode laser, which is what we sometimes refer to as the red diode, because of the wavelength, is pretty much the go-to here. You’ll see in all of the ROP studies, this is the wavelength of laser that is used. Now, there are different wavelengths of diode lasers. There’s one that they call the green diode. Now, why do we choose this one? This one is by Iridex here in particular. The reason this is selected is that not only does it give you a burn from the RPE pigment underneath the retina, but this wavelength is less likely to heat up the lens, if you have a persistent tunica vasculosa lentis, because of the red wavelength, and therefore not being taken up by red pigments. So the 810 nanometer diode laser is the go-to for ROP. This is an interesting question from Australia, about an injured rugby player. And what surgery or further investigation would you perform on a 17-year-old rugby player who had a fingerpoke trauma induced right superior oblique trochlea weakening? A lot of times when we think of penetrating injuries in this area of the trochlea, what we’re really maybe mostly familiar with is actually getting a Brown syndrome, what we call canine tooth syndrome. But it appears that this patient does not have that. They actually have weakness of the superior oblique. So this patient has what appears to be a fourth nerve palsy, because they’re getting an upshoot in adduction. They have no evidence of blowout fracture. They did have a canalicular tear. And now two months since injury, they have a vertical and torsional diplopia in adduction, which is still being controlled by a face turn. Let’s just kind of switch our share over to the whiteboard and kind of discuss this case a little bit. And that’s coming up. So when we talk about this patient in particular, we don’t really have measurements, but what we have is that the motility — and there are a couple ways to diagram this patient’s motility. We don’t know how much overaction, but they’ve got some overaction, right? So this is one manner to diagram. This would be the overaction of the right inferior oblique. Now, the other way to diagram this, of course, is using this kind of asterisk format here. But it’s kind of the same thing. You’re going to indicate an overaction of anywhere from +1 to +4, typically. Those would be the parameters. So this patient has overaction on adduction, which is basically left gaze. On the face of it, yes, that would be consistent with a superior oblique palsy. They’re two months out now, so whether or not to do anything with this — I suppose depends on a couple things. One, is it improving over time? And two, what’s the magnitude of the deviation? I think that if I think about… Well, what’s the mechanism here? The mechanism doesn’t appear to be truly damage to the trochlea, because we don’t have a Brown syndrome. But perhaps there’s an avulsion of the superior oblique tendon to some degree. And I think that being only two months out, I probably would let this heal a bit longer. Maybe up to 4 to 6 months, before making any decision. But at that point, basically, if it looks like inferior oblique overaction still, and what we would call a superior oblique palsy, then I would do surgery based on that. And if there’s torsion and a hypertropia, worse on left gaze, then I would do something to weaken that left superior oblique. Or I’m sorry. That right superior oblique. But whether you do a recession or a myectomy or you need more than one muscle would really just depend on the magnitude of the deviation. So not having the rest of those details, we’ll just kind of leave it at that, and go on to our next question here. All right. Which is… Here we go. Let me get the correct one. Sorry. Yeah. All right. So back to our PowerPoint… Next question. Can strabismus be corrected using glasses? A question from Nigeria. Well, can it be corrected? Depends on your definition of correction. Does it make anything go away? No. Can it be controlled? Yeah, I think the answer to that is yes. Just a really basic format, when you’re talking about strabismus and glasses. You know, this is why… So all these eso deviations — most commonly in kids — are due to refractive errors. So doing a full cycloplegic refraction is just a critical skill for any pediatric ophthalmologist. Because most of the time what we’re doing is we have esotropia, we have a hyperopic refractive error, and we’re giving the full prescription, trying to relax accommodation and straighten the eyes. Now, what if you have a high AC/A ratio? Normally the difference between esotropic alignment in distance and near is either gonna be the same, or maybe it’s going to be 10 prism diameters, maybe 15. As you start getting in 15 more esotropia at near versus distance, then you can automatically assume that this person has a high AC/A ratio, and while I don’t usually start with a bifocal, some people, if they have a residual deviation at near, but they’re straight at distance, then this is a case for a bifocal. All right? And if I’m going to give a bifocal, I’m usually going to give one that’s relatively the full amount. So anywhere from a +2.50 to plus 3. And as time goes on, if I feel like I don’t need that anymore, I’ll start to decrease it. But I think the first time you go to a bifocal, you’re just gonna go into it the full amount. So yeah. Absolutely, when we’re talking about eso deviations, with any significant hyperopia, more than +2, +2.50, you will always go to glasses. There are times, though, when I see kids that have a low hyperopic refractive error. They’re only a +1.50. But they’re not congenital ETs. They were straight and all of a sudden at age 3, they developed this intermittent deviation that becomes constant. And I will try hyperopic correction in those. Even though it’s a low refractive error. Because a lot of times, they do look — it’s accommodative in nature. And a lot of times, there’s a family history of something similar in other adults or children. All right. Exotropia. It’s really less clear if glasses are helpful. Now, can you overminus people, or cut their plus? Overminus them by 1 or 2 diopters to help control an exo deviation? Yes, you can. I’m not a big fan of it. But people that have mild amounts of intermittent exotropia, or they’re not surgical candidates, for whatever reason, or they don’t want surgery, then doing the overminus technique can be somewhat beneficial. I think it’s never a great answer. In a younger person, definitely teenager or less, they can usually accommodate an extra couple diopters. So if you measure that they’re plano or -1, you might give them -2 or -3, and stimulate accommodation and pull them in. Again, it’s not my favorite technique, but it is a tool that we have. I think most of the time these end up having surgery. And then finally, for vertical strabismus, are glasses of benefit? Not much you can do. I mean, if someone has symptomatic diplopia, yes. Of course you can give them some prism. I find most people don’t tolerate more than 4 to 6, but sometimes you can give them 8 to 10 or more prism diopters and they’re happy. Just remember if you’re going to give someone something like 8 prism diopters, divide the prism. Don’t put it all on one lens. Say, 4 base up on one side and 4 base down on the other. And that adds up to 8, right? You don’t have to put it on one eye, and it’s better to keep the lenses balanced by dividing the prism. That’s a quick and dirty correcting strabismus with glasses. All right. Do you make surgery for accommodative strabismus with a variable angle? And if so, what technique are you using? Well, I think that there are a few cases here. Now, we have to distinguish between a variable measurement, where it’s different every time you see them, in which case I would sit tight and not do surgery, versus someone who has kind of reproducible measurements, but maybe there’s a big distance to near discrepancy, what we were just referencing. The high AC/A ratio. If people have high esotropia distance and near, you need to do a medial rectus recession, of course. I think that’s pretty standard. The question is: What do you do if there’s an excess of near accommodation? So the posterior fixation suture. If someone is straight in the distance, and we’ll diagram this out — so I’m gonna switch over to the whiteboard, because I think these high AC/A ratios are an interesting group of patients. So we’ll just kind of use some examples, while we do this. All right. So a pretty straightforward case would be someone who has ET distance of 35, but an ET near, and remember, we denote that by putting a prime sign, of 40. All right? And no refractive error. Let’s just say this patient is plano. So that’s pretty straightforward. We’re going to do medial rectus recession. And we’re gonna do that medial rectus recession for the larger near deviation. So a case like this, I would usually target this. All right? Now, let’s say that this same patient wasn’t plano. Let’s say that this same patient was like a +4. So we give that. And then they come back and now their distance deviation in their full hyperopic correction is better. Let’s just say the distance is… Oops. So you give them the +4, and they’re a little bit better. So now they’re like 15 at distance. And 30 at near. All right? So what do you do with that one? Well, that gets to be a bit dicey. There are a couple ways to do this. You can do strabismus surgery for the full near deviation. And probably get away with that. If you did the distance, it would probably be undercorrected. So just doing the distance is maybe not the best solution. Especially in a younger kid whose hyperopia is still changing. Now, if they… What I think a lot of people will do is maybe kind of somewhere in the middle. And I think that’s okay too. So they’ll target somewhere here — this deviation. So they’re gonna do their MR recess for 20 to 25. So I think one of these options, either targeting the 30 or targeting something in the middle, is probably reasonable. Would probably not target that. But there are some exceptions to that. When would I target that distance deviation? Well, let’s just say you’ve given them +4s, and the distance is 15. And the near is 30. Well, you might do a BMR for this. And if this is a patient that no longer wants bifocals, because say they’re an older teenager, then you can do a Faden to get this residual. Posterior fixation sutures. Same thing for this amount. And then the Faden gets the residual. But sometimes you’ll see that the distance is zero. We can run into that situation, where the distance is zero, but they have 30 ET at near. Well, now you don’t really need any BMR. You’re just doing the Faden. To target that. One thing that you don’t — and when I talk about posterior fixation sutures for these high AC/A ratios, I don’t do these in the younger kids. So if I have a 7-year-old or a 5-year-old, with a high AC/A ratio, I will try to get them straight with bifocals. I kind of reserve these posterior fixation sutures for the kids whose hyperopia has gone away, and yet they still have this excessive accommodative response at near. So teenagers. I think the Faden for these variable near angles can be helpful to them. When you’re trying to get them out of bifocals. But let’s just kind of discuss the Faden suture for a minute. This will be a pretty typical kind of application for it. Where someone is straight at distance. So just has a small ET, and then has a residual at near. What are we doing with posterior fixation sutures? Well… We are… Here’s our medial rectus. And if they’re straight at distance, we don’t do any recession at all. But what we do is we go back 8 millimeters from here. So from this distance to this distance, that’s 8 millimeters. And we use a non-absorbable suture, preferably. You could probably get away with a vicryl, but I would try to use something like a braided polyester Mersilene kind of suture. And you take a bite of sclera and you take a bite through the muscle. And you’re trying to really pin that down tight to the sclera. Now, how does this work? Remember, our distance was zero. They’re straight. But the near was 30. So how does this work? Well, these sutures that we put in here, these sutures only affect the muscle tension, the muscle strength, the muscle pull. The alignment. They only affect it when the eye is moving in to the field of action of that muscle. When the eye is straight ahead, when the eye is straight ahead, this is our effective insertion there. So we’re not changing the distance deviation. However, when the eyes converge, and are looking at a near fixation target, now this muscle is contracting, and this becomes the effective insertion. So that’s how we get away with that. Now, there is one more variation of this. So what about this patient? Where distance is 15, and near is larger, 40? It’s a pretty crummy eye there. Let’s just fix that. All right. So that’s a case when you’re gonna do both a recession and a Faden. Just change the thickness. Go away! Dun-dun-dun. Okay. So now… We need to get a little bit of distance correction. So this is our native insertion right here. So we need to get to 15 by doing a smaller recession. So I’m gonna do a small MR recess of 3 millimeters, and I’m gonna put the muscle here now. That’s gonna correct this. And then the Faden suture, measuring back another 8 millimeters, Faden suture, Faden suture, that’s gonna correct that. Now, when you get to… When you start doing larger amounts of recession, when you’re starting to recess the medial rectus more than, say, 3 millimeters or so, I don’t usually add a Faden fixation suture. Because it doesn’t seem to really add quite as much effect when you’re already doing medium to large amounts of recession. Plus just from a technical standpoint, as you’re putting that muscle back, and then you’re gonna measure another 8 millimeters back, if you’re combining a posterior fixation suture with a 6 millimeter recession, that gets you back behind the equator. The medial rectus is 5.5 millimeters, roughly. Let’s just say it’s 5 millimeters from the limbus. You do a 6 millimeter recession. You’re now at 11 millimeters from the limbus, and you’re gonna measure back 8 more millimeters and do a posterior fixation suture? That’s retroequatorial. Okay? Because now we are… What is that? That’s 11 and 8? That’s 19 millimeters. That’s why when you start to do larger amounts of recession, you really don’t need, nor is it really possible to do a good posterior fixation suture. Again, the most important thing is: Tie it super tight. You really need to pin that muscle down. All right. Let’s go… And I see people are submitting live questions. We’ve got about eight of them in the queue now. So that’s fantastic, because I’m almost finished with our preprepared questions. So let’s see what else we have. Ahead of time. Exotropia. My comment about exotropia at variable angles is pretty much always you’re going to operate for the larger distance deviation. Which is by far the most common situation. Even if they’re almost straight at near, if the distance is 30, I’m gonna operate for 30. If you get the other situation, where they have a convergence insufficiency, then the exotropia can be greater at near. Then you just need to… I tend to concentrate more on the medial rectus resection component. Or if they’ve had previous surgery, if they’ve previously had medial rectus recessions, I think you really need to look at those medial rectus muscles and see if they’re slipped. Because that’s the other situation where we probably most commonly see these larger deviations of XT at near. So trying to bring that eye in more, you need to concentrate on the medial rectus resection or plication or advancement, as the case may be. All right. I think… This is the second to the last one. Should we correct below 10 to 15-year-olds with less than 1 diopter sphere? With asthenopic symptoms? It’s an unusual situation, admittedly, but yes, of course, I think you don’t treat the textbooks. You don’t treat the tables. You treat the patient. If you have a patient who has asthenopia and low hyperopia, then I would treat them with hyperopic correction, or higher power reading glasses, or bifocals. Or if they have anisometropia, I would correct that. I think there’s no hard and fast rule to these, but if somebody is having discomfort, even if we don’t know why they’re susceptible to it, then yes, of course, go ahead and try the refractive correction. In terms of anisometropia, of course, kids typically tolerate more anisometropia than adults do. Kids can tolerate… Not prism diopters. Three diopters, or unilateral aphakic correction. It doesn’t seem to bother them. Recommended technique to correct pediatric aphakia with no capsule. Okay. So we do run into this. Either you have capsular complications, or someone has removed all the capsule when they’ve done a congenital cataract surgery, or we have a subluxated lens such as Marfan syndrome, homocystinuria, ectopia lentis, which is sometimes idiopathic or familial. What to do in these cases? If you have a very young child and they’re still growing, my preference is to simply use aphakic glasses, if it’s a bilateral problem. Bilateral aphakes with glasses do quite well if you can keep them in glasses. If you have a unilateral, aphakics don’t do so well. Aphakic contact lenses are great for unilateral aphakia. And I think that’s… No matter what the age, if I don’t have capsular support, that’s probably my preference. Because the downside is not much. But that’s assuming you can get the aphakic contact lens, the family can afford it, the family can take care of it. We know that’s not always the case. Suture fixated intraocular lenses. Sclerally fixated. I’ve done these over the years and I’ve been happy with them. I do think that eventually you’re going to have a suture problem. If we’re suture fixating — whether to the iris or to the sclera, we have to assume that a prolene suture or a nylon suture — and I have a preference for the larger ones, like 9-0… You have to assume that eventually it’s going to break or erode. And you’re going to have to replace it or you’re going to have some complication as a result. So yes, that’s available, and if that’s all you have access to, that’s what you do if the situation warrants it. If it’s fine. Just need to be aware of what’s going to happen long-term. AC IOLs — I have not used AC IOLs. They kind of got a bad rap, AC IOLs in children. But those were the old style AC IOLs. I think there may be a place for that in children, especially older children, teenagers. I think the critical elements are having a well designed AC IOL and also an older child with normal angles. So could that be an option? Yes, it could be an option. I probably in my personal situation would still avoid it. Recently, I’ve been participating in the iris claw — the artisan iris IOL study, and I’ve been quite happy with these, but again, these are expensive. You have to have access to them. But this is what they look like. This is currently, to answer your question, this is my preferred technique for IOL placement when there is unilateral aphakia with no capsular support. There are little breaks in these haptics right around here, and it’s very soft, pliable material, and you just imbricate some of the iris in there, and it doesn’t take much, and these seem to be very easy to place, and very well tolerated. Now, you do have to have a minimum depth of probably around 3 millimeters of AC. Do we know what’s going to happen with these in 50 years? No. We don’t. And I’d still have some concerns about endothelial condition, about iris erosion, chronic iritis, but I think that given all the options, this is probably as good or better than suture-fixated IOLs or anterior chamber IOLs. But again, all of these have potential downsides, right? And we just need to be aware of that. This is our final question. Do you measure the amount — final question of the previously submitted ones. And then we’ll go to the live ones. Do you measure the amount of deviation in all directions of gaze? If so, can you elaborate on the procedure? Question from India. No. I don’t. You know, and I think that we have these motility grids that we look at. It intimidates people, and that’s one of the reasons maybe why some people don’t like strabismus. Let me switch over to a new share here. Because I want to show you… What this looks like on the Orbis Cybersight… All right. So I’ll just share my desktop. And let me scroll over… All right. So I started a patient case here. On Cybersight. And I’ve done it within the field of pediatric ophthalmology and strabismus. And for example, here, we have a 3-year-old female. Esotropia. Esotropia. For three months. Visual acuity, maybe some amblyopia. As we get down here, we get to the motility grid section, and this is what I want to show you. Because I find that some people maybe aren’t comfortable using these motility grids and alignment grids. If you select normal, nothing happens. If you have abnormal motility, then we get this. The kids that we see in the office, the routine kids with the refractive esotropia and congenital esotropia, intermittent exotropia. Is their motility usually normal? Yeah, it’s normal. So if all of these parameters — right superior rectus, right inferior oblique, lateral rectus, inferior rectus — if all of those are zeroes, motility is normal, I don’t bother to measure strabismus in left or right gaze, or up or down, unless I see something that suggests to me inferior oblique overaction, upgaze — just when I’m checking motility with my little toy. I go up, the eyes diverge. I can go down, the eyes converge. And I see a little bit of inferior oblique overaction. Okay. So now maybe I do want to look at side gaze, perhaps. But even then, maybe I just want to measure up and down. So if motility is normal, I’m usually not measuring any position other than primary position straight ahead at distance and near. And probably for me, that’s 95% of the patients I see. Just those two measurements and their motility. And that’s all I really need. Now… What if we see someone who has this, though? They’ve got +3 right inferior oblique overaction, and we think that this person has a fourth nerve palsy. Like the rugby player. Let’s say this is the rugby player. 17-year-old. Right inferior oblique overaction and he’s got a head posture, so we know his diplopia is different in right and left gaze. This is a different patient. Now we need to take measurements in a lot of different positions. When you look at the alignment grid here, we select abnormal and the alignment grid comes up. Center square. Primary position at distance. Straight up is upgaze. Straight down, downgaze. This is gaze to the patient’s right. Right? Right gaze. This is gaze to the patient’s left. So like this rugby player with +3 inferior oblique overaction, we think that they have some right hypertropia as a result. Right? And it looks like it’s worse on left gaze. Because the inferior oblique… All right. And it’s probably gonna be less on left gaze. So what measurements am I going to look at? If I start getting these vertical deviations and incomitance, I can say at the very least, these are the measurements I want. If I start to see things like V patterns or A patterns on a motility, then I’m probably gonna want to check upgaze and downgaze too. So as you start getting into these incomitant strabismus… I think a fourth nerve palsy is a very good example of someone where you’re commonly going to start doing other positions of gaze. I’ll move on and I’ll do this, and I’ll do up and down and left and right. And if I feel like there’s a cyclo-vertical muscle with torsion and oblique — when we say oblique diplopia, this is horizontal diplopia, this is vertical diplopia, and this is oblique, where the two images are diagonal. You’ve got a horizontal and a vertical component — if I have that, I’m gonna start looking at head tilts. And in the case of inferior oblique overaction, superior oblique palsy, what do we expect? We expect that it’s more on tilt to the same side. So standard superior oblique palsy… These will be… And of course I’ll have their near deviation. So near with and without correction. These would be the measurements that I would collect. And you’ll notice I haven’t talked at all about these up in the corners. These oblique positions. About the only time I feel like I need these are if someone has a restriction of a vertical muscle. Like a longstanding fourth nerve palsy. You can get contraction of the right superior rectus, in which case down and to the right, they’ll have their maximum deviation. So it’s rather uncommon that I use these oblique positions. I would say less than 1% of patients. But if I’m doing anything more than just primary near and primary distance, my measurements usually will look like what you see on the screen right now. They will be those… What’s that? Five six, seven, eight measurements, perhaps. Okay? All right. So that’s a good question. Always at minimum, you really want primary position, distance and near, and you want to have a good assessment of what the motility is. 90% of the time, for patients, that’s all you need to make an accurate decision. But then you add these other measurements kind of as needed. And the one that I neglected to mention was torsion. Double Maddox rod testing is something that we should all be familiar with. All right. So let’s do this. Let’s now crack into the question/answer live session. We have 16 in the queue. All right. First question is: What would you do with a bilateral exotropic Duane type two? Probably the easiest way to discuss these is with a whiteboard, so we’ll switch to that diagram. So type II. What is type II Duane’s? Let’s draw what the motility is gonna look like. And I like to use these Hs. Just what I… Type II Duane’s. So type II Duane’s… Type I, right? So type I has deficient ab-duction. Type II has problems with ad-duction. And so sometimes we call this ET Duane’s, XT Duane’s, and then type III is both. AB, AD, so both your abduction and adduction are affected — a lot of times, that balances each other out and a lot of times they don’t have much of a deviation at all. But this question is about type II, which is deficiency. Adduction. And they are frequently XT. So I see this… Not super frequently. I think I see it mostly when I’m traveling. And onsite and different locations around the world. I seem to see a lot of XT Duanes with upshoots. So XT Duane… A lot of times, they’ll look like they’ll have deficient adduction and they’ll have XT of let’s just say 20. And then they get a big upshoot. Or downshoot. Can be either way. And why are they getting that? They’re getting that because the lateral rectus is tight. So that gets tight. And so the globe will kind of roll above or below this tight muscle, as they try to look in the adducted position. Because the globe is being forced up and over. Oh, I have a very good visual. Let me grab it. This is the world’s largest eye. And I’m gonna temporarily switch back. So you can see it full size. Why do you get upshoots and downshoots with type II Duanes? A lot of times people call it inferior oblique overaction. But it’s not. It’s that eye rolling over the tight muscle. So tight lateral rectus in particular. This is your eye. It’s a giant eye, buphthalmic giant eye. If my arm is the tight lateral rectus, and if they’re trying to go against that muscle… What happens is the back part of the eye wants to roll up. Or over that tight muscle. Because it’s not stretchy. It’s like… It comes against that tight part. My arm, the muscle, and it’s like pushing a ball against a string. It’s gonna want to roll over or under. So that’s where these upshoots come from. Now, how do we avoid that? We do Y splitting if. See if I can diagram that. It’s a tough one. I need two arms. When we Y split the lateral rectus, if this is the lateral rectus, we’re splitting the ends, so the lateral rectus is splayed out. Now the muscle halves are like this. And it’s kind of like the ball gets caught in the split there. And it’s not gonna roll up or over. So we can diagram that out a little bit better. So let’s go back to the whiteboard. So this would be a common… The question is about a bilateral type II Duane’s, but I’m gonna keep the example as a unilateral, because the treatment is the same. You’re just gonna do the same to both eyes. And this is by far the more common thing to see, is these unilaterals. So we have an upshoot. And we have XT. This would be a pretty typical type II Duane’s. Maybe a little bit deficient adduction. We’re gonna treat this with my magic ball Y splitting. So let’s look at what that looks like. Remember, this muscle is tight. This lateral rectus is tighter than normal. So you get more correction per millimeter of recession than you would normally. So here is the eye. And then the normal lateral rectus. So I hook it. I isolate it. Before I suture it… And before I disinsert it, I’m going to take a Stevens hook. A small hook. And I’m going to put it under the muscle, and just kind of poke it through from the underside. So that I make a divide. And now I’m going to sweep that hook forward and backward until I divide that muscle. All right? So how far back do you go? Just kind of as far as you can reach. You don’t have to get all the way back to the muscle belly. But you’re trying to split at least about… Let’s just say roughly 10 millimeters or so of the muscle. It’s kind of what you can reach comfortably with the hook without freaking out. And then once that’s split, I’ll go ahead and I’ll take two sutures. One on that half. And one in this half. Now I’m going to take my scissors, and disinsert the muscle. All right? So let’s get this muscle off. And I’m going to draw… This was the original insertion right there. We’re going to recess back… Whatever. Let’s just say we’re gonna do a 6 millimeter recession. So the new insertion is gonna be about here. 6 millimeters back. And we’re going to have this split muscle. So now… This is kind of what the lateral looks like. We’ve done this Y split procedure. The recession here… The recession component will take care of the 20 XT. The Y splitting… This part… We’ll take care of the upshoot. So in the case of… The bilateral case… I would do your bilateral recession for your exotropia deviation. And if there’s no upshoot, that’s all you need to do. Is just recess the laterals. But there’s usually an upshoot with type II Duane’s, and if there is an upshoot, I will add this Y splitting procedure. That’s a great question. Thank you. All right. Okay. So we’ve done that one. Next question. How do you approach large angle squint needing both eyes surgery under local anesthesia, if the patient is not fit for general anesthesia? Well… So I will admit I don’t do a lot of local anesthesia surgery. But how will I go about this? Well, I think that a lot of times, with large angle surgery… Well, let’s assume one thing. Let’s assume that this is at least a child old enough that you can do it that way. If it’s an infant, that’s gonna be a totally different story. But let’s assume that the patient is cooperative enough that you can do it this way. With local anesthesia. And sedation. I would say most of the time deviations up to 50 prism diopters… You can just do two muscles. So I would say probably most of the time that’s going to be your answer. But let’s say you had someone that had even larger deviation, some adult that’s got 90 XT. I think you could still do it. I would do a little bit of IV sedation. And I would do a sub-Tenon’s infiltration. I don’t think that there’s any real advantage to doing bilateral retrobulbar blocks. As a matter of fact, there’s some danger to that. But a lot of these you can just do… I think sub-Tenon’s infiltration is a great way to do local anesthetic for strabismus surgery. And a lot of times we’ll even put this in at the end of the case, through our fornix incision. What does sub-Tenon’s infiltration look like for local anesthesia surgery? Let’s go back to the whiteboard. Most commonly, we’re talking about… We’ve got our globe. And basically… So if the patient’s young enough that you can do the surgery through a fornix incision, I think that’s quite helpful. And if I was going to do that, I would just do my fornix. Say we’re doing XT here. You do topical. Before you make this big incision, I should probably back up a little bit… All right. So we’re gonna do topical. These are the topical drops coming on. After we’ve done topical, then we’re going to just do a little bit of local right here. And you can do that… You may not even need to do that. In terms of any injection. A lot of times you do enough… But you can do like a small 30-gauge needle if you need to, but a lot of times with topical, you can take your scissors and make a small little incision like this. Once you’ve got that little conjunctival incision, then you use a blunt cannula. You don’t use a needle at this point. And you can just… Like the ones that are on… A lot of times go on to BSS bottles for irrigation. Something similar to that. Or that. You can just use a blunt tipped cannula, and infiltrate your 1% or 2% lidocaine. And you can add marcaine if you want to. But that’s an easy way to do sub-Tenon’s infiltration. We’ll sometimes put this in at the end of cases. If you were doing a limbal incision, I think you can still do the same thing. But I would probably start off… If you’re gonna do this through a limbal incision, usually I start right here at the limbus, but I think if I was going to do topical, I would probably start with one of the radial incisions and do my infiltration and do the rest of the incision. But that seems pretty reasonable to me. Anyone out there has an alternative suggestion, just throw it up on the chat and I’ll mention it. I don’t think it’s a big deal. For us, it’s just kind of super easy, and with the anesthesia that’s available… But there are cases when you do have it do it under local. But say you want to do it under local, say you’re doing adjustable surgery and you don’t want people real sedated. All right. So back to our question and answers. Prescribing astigmatism in young children. And yeah… That comes up. One of the things I see people doing sometimes is not prescribing the astigmatism correction. They’ll get half of it. Rather than the full amount. Thinking that they kind of have to adapt to it. Now, with kids, that’s usually not the case. That’s one of the nice things about kids. Is that even teenagers — it’s rare that I do a manifest refraction. I usually do a full cycloplegic retinoscopy, and give them what I want them to have, and they adapt to it. Now, one of us, an adult, getting a refraction like that, it probably wouldn’t work out very well, which is why we tend to move to subjective refraction, as you start dealing with adults. Because we want to know what’s comfortable. Because we become so sensitive to it. But kids are very plastic. And they’ll tolerate just about whatever you give them, unless it’s the wrong prescription. So how do I do astigmatism? Let’s go… Answer that. So we’re gonna roll them back to the whiteboard here. All right. We see a kid. We measure the prescription. We’re +2. +4. Okay. At 90. So if you do plus cylinder, work in plus cylinder, it’s pretty typical. If this kid’s eyes were straight, what glasses would I give them? Well, if they’re straight, I don’t need to give them the hyperopia. They’re probably fine with accommodating 2 diopters. So I’m probably gonna give them plano. But I’m gonna give them the full cylinder on the correct axis! And if it’s oblique, I’ll give them that. If it’s at 90, where it normally is, I’ll give them that. But I don’t think there’s any reason… What I would not do is I would not go…… Let’s see. What might you do? So some people might do something like this. They might say… Well, I’m just gonna give them 2. And then I’m gonna give them the other 2 diopters as spherical equivalent. Give them +1 at 90. Well… I guess… Why? I would not do that. So if I’m giving someone cylinder, if I’m correcting their astigmatism, they’re gonna get that. Now, if they don’t tolerate that, which is very uncommon, then they’re probably going to be an older kid, where maybe I need to go back and refine it with subjective refraction. So most of the time I’m doing cycloplegic. But if that doesn’t work out, then I’m gonna do manifest refraction. All right? But by and large, I think it’s recommended to just go ahead and give them the full cylinder on the correct axis, and you don’t need to wean them into it. Just usually if you’re prescribing hyperopia or esotropia, we usually don’t build up to their hyperopic refraction. We usually just give them the hyperopic refraction, and they’re fine. So it’s only the very small minority, which I would say is less than 1%, easily, that I have to go back and refine after the fact, with subjective refraction, manifest refraction. Full astigmatism on axis. All right? Next question. What are the indications for vision therapy? Well, yeah. The indications for vision therapy are… Probably depends on who you are. And where you live. For me, we do have a lot of vision therapy optometrists in the area. I think for a lot of things, it’s not really something that I utilize. For me personally, vision therapy is mostly convergence related. So patients with perhaps intermittent exotropia… Particularly if it’s convergence insufficiency… I think that that group of patients does pretty well with… Let’s not call it vision therapy. Let’s call it exercises. We are all built to converge our eyes. We do that all the time. If I look at my finger right here, I’ve got to converge my eyes. So I have that ability, and you can enhance that ability. I find it… If you have longstanding congenital vertical muscle palsies, congenital longstanding superior oblique palsy, we do build up good vertical fusion amplitudes. But that’s when you’ve had it from a very young age. If it’s acquired, people don’t build up those vertical fusional amplitudes. So I think it would be very difficult to say that you could teach someone as a teenager or an adult to compress vertical diplopia. And same thing as… How do you teach someone to diverge their eyes? If someone has esotropia, how to teach them to diverge their eyes? So there’s some things with some elements of vision therapy that don’t really make sense to me. Now, that said, I’m sure that you can find a billion experts who will take the alternative approach, and say: Well, it’s useful for this and that. But for me personally, it’s pretty much restricted to convergence insufficiency type situations. Next question is related to the question of the rugby player, with the traumatic right superior oblique palsy. And they said… You said you would do surgery to weaken the right superior oblique. Do you mean weaken the right inferior oblique or tighten the RSO or other? Absolutely. If I said I would do surgery on the right superior oblique, that is not true. That patient had what looks like a right superior oblique palsy. And overaction of the right inferior oblique. So I would do surgery on the right inferior oblique. And if I did say that, let’s just clarify that. Because that is absolutely not correct. So I’m going back to the whiteboard for a minute. So in that situation, we had someone that looked like this. We don’t know the deviations, but we know that we had right inferior oblique overaction. All right? That’s the RIO. And presumably because the RSO was injured. It got whacked. Stretched. Whatever happened to it. All right. So the person bringing this up said: Did you mean you would strengthen the RSO? No. So I would not tuck… I would not tuck the right superior oblique. I think that is — the only time I’ll do that is if it’s a congenital lax tendon with a profound superior oblique palsy. Now, I suppose if you did traction testing on this, and it felt really lax, you could consider it. But I suspect it would be fraught with difficulty. I think my go-to… As long as this — what we don’t know here is we don’t know how large the deviation is. So there’s a little bit of an unknown. But let’s just assume that the RHT is anywhere from 5 to 15. Something like that. In this situation, what would I do? I would go right here. And that is the action of the right inferior oblique. I would do a right inferior oblique — right inferior oblique weakening procedure. Right? I usually do myectomies, but if it was a very small deviation, I might do a recession. But typically when stuff is in the range of 6 to 15, I’m doing a myectomy. Inferior oblique myectomy. So yeah. That would probably be my go-to there. All right. So we got that cleared up. Yeah. Thank you. If I do say something wrong or crazy, point it out to me. Because hopefully I’ve just misspoken and I’m not actually wrong or crazy. Both are possible. All right. So answer that one. Next question. What is your protocol for near distance disparity intermittent XT? Well, we did touch on this with one of the initial questions. But let’s go back to that. It’s pretty straightforward. Near distance disparity for intermittent XT. It’s a common situation. Right? So let’s just assume motility is full. And pretty typical situation… XT at distance… 30. XT at near. XT prime. Let’s just say… I’ll make it a little bit exaggerated. I’ll say it’s 15. So what’s my protocol for that? BLR, bilateral lateral rectus recession. For 30. Which is gonna be for me…. 7 millimeters. So that’s one very common situation. Am I worried about overcorrecting at near? No. If it was zero, I might be a little bit hesitant. But if it’s… If they have some deviation at near, and especially if it’s not a 2-year-old or something super young, I’m not so worried about that, I will pretty much always target the distance deviation when the distance deviation is the larger of the two. All right? What about the other situation? What if the distance deviation is not the larger of the two? We have a convergence insufficiency type situation. So XT at distance is 10. XT at near is… 20. All right. That’s more complicated. Because now we’re worried about giving them diplopia at distance. Which definitely does happen. New cough drop. Excuse me. All right. When I have this situation, or when I have this situation, I’m really… What I’m wanting to do is tighten the medial rectus. And I will resect it… Or plicate it. And I’ll probably go on from this, to take about plication, because I love plication now. I will try to strengthen that medial rectus in the hopes that that gives me more correction at near. Let’s exaggerate this situation a little bit. Let’s go to a true convergence insufficiency. So XT distance… Zero. XT at near… 20. These are tough. I don’t like these. Because if you’re going to fix them, you’re going to give them some diplopia at near. Do you do bilateral medial rectus resection for 20? Probably not. Because you can create a situation where both eyes are… Let’s just say restricted, esotropic. And there’s no head posture that that patient can get, which gets rid of the diplopia. While they’re healing. It probably loosens up over time, and maybe they do okay. But they’re gonna be super diplopic for a while. So in these situations, and these are tough, and I don’t think there’s a right or wrong answer to these, but what I might do with someone like this… Is just resect one. So I’m just gonna say… One, RMR resect. Because now let’s just say… Okay. This is reverse right eye… I’ve created an esotropia situation early after the surgery. They can now adopt a head turn, and they don’t have both eyes restricted in. So I think that the patients are more comfortable. Whether or not it gives you the same long-term result I think is debatable. But this will be my copout, to try and get that near deviation enhanced. Let’s talk about plications for a minute. The last few years, I’ve switched to this. All right. So resections, we all know what we do with resections. Right? We have our muscle. And we put our suture back here on muscle. And then we cut out that section, and we pull everything forward. Right? That’s a resection. That piece is gone. Plication is… Just another way to do this. And it’s one of those techniques that maybe used to be popular, fell out of favor, and now it’s coming back around. As things do. But I’ll tell you why I like it. Plication… Muscle… All right. So I put my suture in the muscle. Same spot as resection. Same surgical tables. No change. And then I pass… I take my sutures, and I go through sclera right here and right here. So that’s going through there and that’s going through there. And I have a very thin muscle hook. Underneath the muscle right there. And kind of pull it up. And so then what we’re doing is we’re creating a fold. Where it looks kind of like this. There’s a fold of muscle. Lumped up like that. With the suture going through sclera there and there. And this is all that I do. So that fold… The reason I like this is that you’re never cutting the muscle. So there’s no chance that that suture is going to pull out. Right? Especially on some of these reops, where the muscle is under a lot of tension, or it’s on the medial rectus. You can lose these on resections, if the muscle suture pulls out. And I just use a regular 6-0 vicryl suture. I don’t use anything permanent. And you can say… Well, once that suture dissolves, it’s just gonna come undone. And I’ll tell you, it does not. Because I have reoperated on them about three weeks after, thinking I could take it down. No dice. It is fused. So what’s the downside to this? The downside is making sure that this suture is tight. That’s got to be tight. If there’s any gap, like I’m kind of showing here, that’s no bueno. That’s gotta be super tight. Now, at first… All right. Let me just fix this a little bit. At first, yeah. There’s this big lump. Right? A big lump of tissue right there. And it looks kind of ugly at first. But if you do reoperate on these a few months later, it looks like… If you go back and reoperate on this, say even three months after, that lump of tissue is gone. And all you see is just this. I mean, it basically looks like an unoperated muscle. So I do this because… I don’t know if it’s easier. I think it’s safer. I think it’s faster most of the time, unless you get sagging in the suture. And then the other reason I do it is that it will… It just goes away, and the muscles look really good, and you keep it nice and spread out. So it really stays a nice healthy muscle. I don’t think it spares any vessels. I think if that tissue is disappearing, then those vessels are occluded. Although there are some research studies that would suggest that plication is vessel-sparing. So there’s that. Next question. Next question is: Nine-year-old girl complains of blurred distance vision. On examination, by autorefractor, she’s a -10. Giving her cyclogyl three times a day for three days. So I think this… Okay. So the question is: She’s a -10 on examination. And then they give her cyclogyl three times a day for three days and repeat the refraction and find it’s only a -5. So she appears to be having like an accommodative spasm, or let’s just call it accommodative spasm. That’s creating this artificial high myopia. And can’t see good without cycloplegic drops. So if they cycloplege her, her vision clears up. But if she’s not cyclopleged, she’s a -10. That’s basically what’s going on. What do you do with these? I’ve seen a few of these. It’s not super common. But you’re on the right track with this. I think you have to keep them cyclopleged for a period of a few weeks. Or even a few months. So I would recommend doing atropine, 1%. Because cyclogyl burns, and you have to use it several times a day. But a patient like this… I would give them atropine 1% once or twice a day. So that they’re fully cyclopleged. And then once they’re fully cyclopleged, whatever glasses it takes for them to see clearly, you’re probably gonna have to include a bifocal, plus whatever their distance correction is. I would give them that, and then have them — just follow them until their accommodation relaxes. That’s what I would do there. And usually they’ll eventually just stop. Bilateral exotropic Duane syndrome. We answered that one. How should uniocular… So monocular strabismus due to organic condition like congenital macular scar be managed? Refraction failed to improve vision. Does cosmetic surgery have a role? So we do see these patients. They’ll have complaints of distortion or diplopia. And you do their exam and their eyes are straight. But then when you cover the eye with the macular problem, the diplopia clears up. You know, you have to explain to them… Even if they do have strabismus, there are two elements to their visual problem. One is the retinal problem, which is nothing you can do about, and the other is the alignment. If they have a cosmetic alignment issue, then you fix that as needed. But as long as that does not give them diplopia, it’s okay to realign them, based just on cosmetics. But I think the main thing is differentiating: What distortion is from the retina and what distortion is from the strabismus. And then treat those individually. All right. Diagnosis and treatment of accommodative spasm. We just discussed that one with the atropine. For a prolonged period of time. This is an interesting one. How do you treat restrictive strabismus induced by scleral buckle surgery? Also, how long do you wait until you opt for surgery? So scleral buckles do induce strabismus. Diplopia. Not uncommonly. A lot of this is technique-related. And I know that, because when I see these, they tend to come from… Seem to come from the same retina surgeons. Over a period of time. And then I have other retina surgeons that I don’t see this from. So some of this is technique-related. These buckles — some of them are thicker, larger than others. Some of them have sponges. I think commonly I see that the superior oblique tendon is involved in the buckle. My approach to these is to leave the buckle on for 6 months. By then, most retina surgeons feel that it’s typically safe to remove it. And that’s my preference. I get permission from the retina surgeon that put the buckle on, and then when I do my strabismus surgery, I remove the buckle. And if they need… If they have small deviations, then a lot of times, just removing the buckle is all you need to do. If they have larger deviations, then you need to remove the buckle, plus do strabismus surgery. Now, can you redetach after removing the buckle? Yes, it happens very rarely. But most of the time… And you warn them about that. But I would say the chance of that happening is less than 1%. I do recommend that after the buckle is removed, that they see the retina surgeon within a week or two, to kind of just reevaluate. And if we’re told not to remove the buckle, I don’t. You can operate with the buckle in place. But a lot of times, the buckle is the problem. But if someone just has a very straightforward esotropia or exotropia, maybe a vertical deviation, then you can do that. It’s just… Sometimes you end up sewing the muscle on the buckle. A lot of times, I find that all the muscle tissue anterior to the buckle has atrophied, because of ischemia. And it’s just gone. It’s just like when you do a tuck or a plication. The muscle tissue is gone. So… Again, I try to wait six months before I do these buckle diplopia surgeries. All right. Next question is how do you make a balance between giving overminus glasses to exotropia and myopia control? How much to overminus people? There’s no formula to that. The younger they are, the more they can tolerate doing that extra accommodative effort. Can you overminus a 7-year-old by 2 diopters? Absolutely. But a 17-year-old — you may not be able to get away with that. So in an older patient that can do manifest refraction, I think I would do that, to see how much minus they can accommodate and tolerate. But they still… They might be able to do it for a short period of time, but not for a long period of time. So they might get asthenopia. Usually it’s 1 diopter, 1.5, maybe 2. There’s a little bit of trial and error there. Again, not a big fan. I think the utility of it is rather minimal. Next question. What do you do if the medial rectus muscle slips during surgery? Medial rectus is about the only one this really happens to. The other muscles don’t go anywhere. I know the inferior and superior rectus have attachments to the oblique muscles. The lateral rectus has a very long course before it goes through posterior Tenon’s, so you don’t really lose that one, typically, unless it’s a reoperation. So usually we’re talking about the medial rectus. Either during recession or resection. Now, I think the thing to do is not freak out and panic, number one. Okay? Number two, you need some visibility. So I like to take cotton tip applicators, cotton pledgets, and soak them in Afrin. Vasoconstrictor. Or phenylephrine. You can do that too. And get the field super dry. All right? Once you get the field super dry, then I will look for the muscle. People make the mistake of looking along the curve of the globe. It’s not there. You need to look along the nasal-orbital wall. That’s where you’ll find the little funnel of posterior Tenon’s, where the muscle has retracted to. And usually if you just carefully explore that without grabbing things, just carefully pushing things around, you can find that little end of the muscle, and if the field is dry from hemostasis, it’s usually pretty easy to identify that. Then the trick is, though, getting it out of there, and getting the suture in it, without chewing it up with your forceps. That’s where the trick comes. And you just have to be super patient. If you find that you cannot find it, then probably the best thing to do is just stop. Stop. Let the patient heal. Go back on another day. And what I would do, when you go back, I would have… If you can have another surgeon with you, especially one that’s more experienced, I think that’s great. I think having good illumination, like a headlight, you can even use a battery operated camping headline, something like that, having good illumination, and just go slow. And don’t just be picking at things and making it bleed. But look. The key here is you need to look along the nasal wall of the orbit. Don’t look along the sclera. It won’t be there. That’s a good question. Next question. After lateral rectus muscle recession, this is a hangback, the patient has an abduction deficit of -2 or -3. All right. And this is in the early postoperative period, it sounds like. Yeah. If someone comes back and they’re a little overcorrected at one week, I don’t get too concerned. But if someone comes back one or two weeks after surgery, and they have a big time duction deficit, -2, -3, then I’m worried that that muscle has slipped. And that’s a case where I would definitely consider exploring and finding out if you need to advance that. If it’s just a mild duction deficit, I would sit tight. Because these will change over time. But a recession, and now they’re -2, -3, on their duction, yeah, I probably would take a look at that early on, rather than waiting. How do you manage a case of accommodative spasm? That’s a popular question today. Atropine, like we talked about. 1% atropine every day with bifocal glasses, and just wait until it breaks. And it can take weeks or months for that to go away. What is your recommended cutoff age for implantation of scleral fixated IOLs in children? Well, I would not do them in young children. When I do a scleral fixated IOL, it is in a teenager who is no longer growing. Their refraction has stabilized. I’m confident that whatever IOL I predict is going to be the one that’s gonna be good for them. For hopefully the rest of their life. So yeah. I don’t do scleral fixated IOLs in kids under 10, for sure. It is usually the older teenagers, when I choose to do that. Another Duane syndrome type II question. In Duane syndrome type II with XT overshooting, does lateral rectus recession alone give the same effect of Y splitting? No. It gives some, though. So just a simple act — it’s a good question. Just a simple act of recessing the lateral rectus will reduce some of the upshoot. But if you have a very prominent significant upshoot, the Y splitting is definitely more effective when it comes to treating that. Differential diagnosis of an isolated inferior rectus palsy in a healthy young woman. And they’re specifying that myasthenia gravis is excluded. Okay. Uncommon. But you do see this from time to time. And I think your point about myasthenia gravis is a good one. You get these weird things like this, and you always have to think of myasthenia. So to me, it’s uncommon. It’s a partial third nerve palsy. It’s a lower division third. Can it still be microvascular? Yes. I think the thing to exclude here is an MRI of the orbits and brain, and rule out things like meningioma of the third nerve. Microvascular disease you’re probably not gonna necessarily pick up, and this is a young healthy woman, so that seems unlikely. I think you want to rule out the opposite problem. You want to rule out restriction. Of the superior rectus. Because that’s the other thing that could look like an inferior rectus palsy. So if there’s any question about possible thyroid disease, maybe a CT scan to look at the superior rectus, if there’s restriction. If there’s not restriction, maybe less likely to do that. But that would be another possibility. So maybe if it’s possible to just get an MRI, that takes care of both. You can look at the muscle thickness. On the superior rectus, you can look at the third nerve, to make sure it looks okay. And that’s probably about as far as I would go. Other than maybe watching it for a little bit before deciding to do surgery. Indication for dynamic retinoscopy. I don’t do it very often. But if someone’s symptoms would suggest that they are not accommodating very well, they’re having blurred near vision, that would be the main thing, then dynamic retinoscopy is something you could check. High hyperopes will sometimes have poor accommodation. How do you do this? You have them look in the distance. You do your retinoscopy, and you should be able to see with motion. And then when they look at your retinoscope and they accommodate, they should basically be neutralizing that, and it should look like a neutralized reflex, or even a minus reflex. Basically, I do that when there’s an indication of blurred near vision. At what age do you start prescribing astigmatism? Really depends on how much it is. Before one year of age, I almost never give any kids glasses, unless there’s some extreme circumstance. So say I saw a six month old and they had four diopters of astigmatism. I probably would just see them back at one year of age. Starting at one year of age, when kids start to walk, if someone had 4 diopters of astigmatism, I would give that even at one year of age. But if at one year of age they had 2 diopters of astigmatism, I probably wouldn’t. Definitely not if it was not… With or against… If it was at 90 or 180, I would probably sit tight. Now, what if they have… A one-year-old and they have three diopters at an oblique axis? We know that’s more amblyogenic? I would probably start to think about it. But most of the time, I will say that a normal range of astigmatism that’s not amblyogenic… I wait until they’re school age. But if someone has amblyogenic amounts, which is usually more than 2 diopters at 90 or 180, and definitely if it’s oblique, then you have to start to consider it, even in the younger kids, the preschool kids. All right. Next question. If the angle of esotropia changes over time, the diagnosis is accommodative change or exo DHD? Yeah. I would say if the angle of esotropia changes over time, I don’t think I can automatically reach a diagnosis with that, because DHD is uncommon. Unless it’s in the setting of congenital strabismus, congenital esotropia, congenital exotropia. I think the most likely thing is someone’s accommodative abilities change as they get older, even children. But I think it would be case by case specific to answer that. All right. If the lateral rectus muscle has slipped, where do you find it? Question — inferior oblique location question. If it’s slipped, because it’s wrapping around the side of the eye, you’re generally looking in the location along the sclera. Where the lateral rectus path would be. And I think right along where the insertion of the inferior oblique is, it would be a pretty natural spot for it to be slipped to. So that’s about 8 millimeters back from the insertion. It’s uncommon that you find it slipped back further than that. Unless someone’s already had it recessed, and it’s back by the exit through Tenon’s capsule. A little easier to find. A lot less likely to happen. Next question. What is your experience or opinion about combined recession-resection procedure in cases of near distance disparity strabismus? This is another way to get the posterior fixation suture effect. You are simultaneously recessing and resecting the same muscle. I don’t know. I know that people do it. I know that some people like it. I have never tried it. I honestly don’t have a personal opinion. I am happy enough with Faden sutures that I do that. If someone didn’t have the suture, or a good needle for posterior fixation suture for Faden, then maybe combined recession/resection makes sense. I just get a little bit nervous when you are doing resections on muscles, and Fadens are hard enough to reverse. Taking down a Faden is not easy. But reversing a resected muscle is really tough. So any time you’re doing resections, I like to be rather confident that that’s what I need long-term. A little leery of that. But again, I don’t have any personal experience. I don’t have a problem with people doing it. I think it makes sense. Okay. And this is going to be our final question. It’s the last one in the queue. And I have a trauma call that I need to answer. Congenital right superior oblique palsy. Primary position is a right hypertropia of 30 prism diopters. Typical head tilt, head turn measurements, and eye movements. Would you operate — right inferior oblique myectomy alone or combine right inferior oblique myectomy with another muscle? This is a good question to discuss, last one in the queue. Let me switch over to the whiteboard for this. Dun-dun-dun. Here it comes. All right. Come on whiteboard. There we go. So in this case… The proposed patient is a typical right superior oblique palsy with right inferior oblique overaction. But just a larger deviation. So let’s just say…+3. We’ve got a fair amount of right inferior oblique overaction. And then we’ve got 30 RHT. RHT. All right. So this is a common situation. Common-ish. When I have a right superior oblique palsy like this, if everything is typical, the first thing I’ll do when I sit down at the surgical table is I’ll do traction testing. What do I want to know when I do that traction testing? I want to know what the SO feels like. So I do traction testing, and I want to feel if the superior oblique feels normal, like an acquired palsy, or if it feels extremely loose. If this is very loose, if it is lax, then that person might get an RSO tuck. And how much tuck do you do? You do enough to where the two eyes feel normal on traction testing. Tuck until they feel equal. So that may be all that they need. If you do a tuck, and you can normalize the traction testing, that may be it. However, let’s say you do the traction testing and it doesn’t feel that bad, or both eyes… Even though it’s right inferior oblique overaction, both eyes feel similar, what do you do with that? Let me just dump this out. And 30 RHT. So I do the traction test and it feels… Okay. We’re only a little bit off. And maybe I don’t know how to do a tuck. I’ve never done one, or I’m afraid of them. What will I do then? Well, pretty much my go-to in this situation… Is I’m going to weaken this. I’m gonna take care of that. So number one… I’m going to do a right inferior oblique weakening. And I like myectomy. That’s gonna get me about 15 prism diopters. All right? So now I still have 15. What am I gonna do for that 15? Well, most commonly, I’m going over here to the left, the contralateral inferior rectus. So if they have a right hypertropia, it’s usually worse on left gaze. Usually there’ll be more again, because of this. They get more hypertropia on left gaze. And I need left acting muscles. Most commonly, I will do this. I’ll recess the contralateral inferior rectus. And I need 15. So at 3 prism diopters per millimeter recession, that’s a 5 millimeter recession for me. That would be my go-to, probably 80%, 90% of these larger deviations. I only do tucks when the tendon is really lax, and I only do them on occasion. I kind of like to avoid them whenever possible, just because superior oblique is not the most forgiving muscle. If it just doesn’t turn out. Okay? All right. That brings us to the end of our queue. And the final comment here from Dr. Ehrenberg is thank you so much for your great talk. Happy new year. And likewise to all of you. Thank you, everyone, for tuning in. We had a great turnout, and these were very good questions. I’d like to do this with other subspecialties too. So if you have any requests for question/answer sessions or lectures, please send them to us at [email protected] You’ll find that on the website, the support address. Send us your suggestions. We love doing this. And I personally — I really like these question and answer sessions. And I’m glad that you appreciate it. If you don’t like the whiteboard, tell me that too. I think it’s helpful. But if it’s a pain in the neck, let me know. If you don’t understand what I’m saying, let me know. We welcome any criticism or compliments. I wish everyone a good new year, and happy holidays to everyone, and we’ll see you in 2020. Bye!
December 23, 2019
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