The causes of an abnormal head posture are myriad and can be quite difficult to understand. The many causes will be carefully explained in an easy to understand way by a leading and highly experienced pediatric ophthalmologist, Dr. Lionel Kowal.
Lecturer: Dr. Lionel Kowal, University of Melbourne, Australia
Panelist: Adedayo Adio FWACS, Consultant Pediatric Ophthalmologist
University of Port Harcourt teaching hospital, Nigeria.
Chairperson, Nigerian Pediatric Ophthalmology and Strabismus Society (NIPOSS)
DR KOWAL: Dr. Adio, thank you very much. Well, good morning, Nigeria. I’m going to talk today about abnormal head posture. No disclosures. When a patient comes to see you with an abnormal head posture, the first thing you have to work out is: What is driving the abnormal head posture? Is it being driven by something visual? Or is it being driven by something unrelated to vision? And that will tell us which book we open to find out more. If the abnormal head posture is visually driven, either doctor — tell the patient “close your eyes and hold your head straight”. If with the eyes closed, the patient holds the head straight, then the abnormal head posture is visually driven. If the abnormal head posture is not related to vision, when I say to the patient “close your eyes and hold your head straight”, then the abnormal head posture is not improved. Both eyes closed is the same as both eyes open. And the problem is oto-neurological. And sometimes it seems to be both visually driven and oto-neurologically driven. If it’s oto-neurologically driven, we owe a lot to people like Agnes Wong and her wonderful textbook. And this is an example of a recent patient who comes in with a head tilt, and when I ask him to close his eyes and straighten his head, of course his head tilt does not change. And his head tilt is not visually driven. When we are describing head tilts, there are three Ts. We describe the tilt, the turn, and the tip. The tilt is to the left or to the right. The turn is to the left or to the right. And the tip is up or down. And I measure as accurately as I can, and I try to use a protractor. It’s often simpler to use an electronic protractor from my iPhone, to measure these important parameters. Usual causes of head tilt are listed here. The commonest cause is a vertical strabismus. Other causes are ocular tilt reaction. Childhood nystagmus. Either idiopathic infantile nystagmus, or the torsional form of fusional maldevelopment nystagmus. Ciancia’s syndrome can cause a head tilt. Incorrect astigmatism correction can cause a head tilt. Head tilt can uncommonly be caused by restriction of the orbit, by spasmus nutans, and by a rare condition, paroxysmal torticollis. Face turn. Commonest cause of face turn that I see and you will see is probably incomitant horizontal strabismus. Childhood nystagmus will cause a face turn. Commonly idiopathic infantile nystagmus, fusional maldevelopment nystagmus, periodic alternating nystagmus. The horizontal component of Ciancia’s syndrome will cause a face turn, incorrect astigmatism correction will cause a face turn. I’ll go through a lot of these causes in more detail in a few moments. Uncommon causes of a face turn: Horizontal gaze paresis. A hemianopia, an orbital restriction. Tip up, tip down. Commonest cause that I see is incomitant strabismus. The congenital fibrosis syndromes, the alphabet patterns, thyroid eye disease. Idiopathic infantile nystagmus with a vertical null, or a vertical gaze paresis. Uncommon causes of a tip are listed here. The pretty rare but difficult to assess paroxysmal tonic upgaze, paroxysmal topic downgaze, the SCA syndromes in the third decade of life, and Sandifer’s syndrome. So we have this pretty complicated jigsaw puzzle, with all these different types of abnormal head posture, all these different diseases, and we need to sort them out. Today I’ll consider a few examples only. A head tilt to the left. A face turn to the left. And tip up and tip down. I’ll also look at any of these abnormal head postures as the null for nystagmus. When it’s the null for nystagmus, it needs evaluation for convergence null. Convergence null for both near and for distance, as we’ll see. Now, this is probably the most important slide of the whole talk. When you see a child or an adult with abnormal head posture, you have to assess whether it is present or whether it is driven by both eyes closed, both eyes open, and only with both eyes open. So here we have the lady on the left — has a head tilt. And when either eye is patched, and she’s only using one eye, then there is no head tilt. RF, right eye fixing. With a right eye fixing, she has a head tilt. And with the left eye fixing, she does not have a head tilt. And LF. Here we have with the left eye fixing. She has a head tilt. With the right eye fixing, she has no head tilt. And here we have a head tilt to the left that is present with both eyes open and also with either eye fixing. The important little gadget down on the bottom right hand corner, pinhole glasses. These are very important in assessing every person who comes to you with an abnormal head posture. Because if pinhole fixes the abnormal head posture, then it’s a refractive cause, and the commonest refractive cause that I see is uncorrected astigmatism. I’m very grateful to Mark Gobin. Mark Gobin — he’s still with us, I believe. He practiced both in the South of Belgium and in the Netherlands. And he was famous or infamous for his oblique dysfunction and his attitude to hyperopia. But his textbook contains many wonderful comments on how to examine patients, and many hints. And he was the first person who pointed out to me the importance of monocular and binocular patching to assess the cause of torticollis. So as we saw here, how important it is to assess patients with both eyes open, and then one eye at a time. He was the first person to bring this to my attention, and this is the cover of his textbook, and a relevant page from his textbook. He mostly wrote in Flemish, and he wrote very little in English. The South Africans who read Afrikaans can understand his Flemish writings, because the language is very similar, but this English translation is a gem. So let’s talk about head tilt to the left, and a few examples. For head tilt to the left, if it’s only there with both eyes open, it’s caused by vertical strabismus. With either eye fixing, there is no tilt. To find out what’s causing the tilt, I tilt the patient’s head to the right. And it’s usually a right hyper. A common misconception is that head tilt is driven by torsion. That’s not true. I think Kushner showed very nicely about ten years ago that head tilt is driven by vertical strabismus, not by torsional strabismus. Head tilt to the left with either eye open. So with both eyes closed, the head is straight. With both eyes open, the head is tilted to the left. So therefore this head tilt is visually driven. And with either eye patched, the fixing eye drives the head tilt. This is infantile nystagmus with a torsional null. Sometimes we see this clinical phenotype without nystagmus, and there’s no good explanation for it. This is a not uncommon clinical presentation, and there are two references there. An old one and a more recent one. For surgically fixing these patients. I find the Von Noorden approach to be technically fairly simple, and not consistently reliable. Dr. Lueder’s approach I think is more complicated, especially the inferior oblique aspect, and more reliable. Now, if we have a head tilt to the left with both eyes closed and both eyes open and driven by left tilt, by left fixation, and driven by right fixation, this is the ocular tilt reaction. The head tilt is independent of visual input. There’s usually a vertical tropia as well. So-called skew deviation. But unlike the head tilt in a superior oblique palsy, the head tilt in ocular tilt reaction is not therapeutic. It doesn’t fix the head tilt. It doesn’t fix the diplopia. The head tilt doesn’t fix anything. Supine position will fix the vertical diplopia, and we’ll see an example of that shortly. The ocular tilt reaction has been very nicely described over the last few years by Agnes Wong in this seminal paper, and this publication of an APOS workshop that I would recommend for you. Here’s an example of a patient who has a vertical misalignment in the top right part of the slide. You can see how she has a right hyper, when she’s sitting up, and when she tilts her head right back, and I stand up on a chair next to her, and take a photo from above, we can see that with her head supine, that her vertical tropia disappears. So this is typical with skew deviation and ocular tilt reaction. Now, the vertical misalignment is otolith driven. It’s not driven by a neuromuscular abnormality. A simple question to ask the patient — every patient — about vertical diplopia is: When you lie down, do you still see double vision when you look up at the ceiling? And that’s a very simple way of diagnosing probable skew deviation as the cause of vertical diplopia. Face turned to left can be caused by strabismus. Here we have a patient with face turned to the left. Left eye fixing. No face turn. Right eye fixing. No face turn. Both eyes fixing, she has a face turn. And we turn the face to the right to find out what is the cause of the face turn, and here the face turn is caused by left esotropia. So the face turn to the left caused by left esotropia. Caused by horizontal strabismus. Face turn to left can be caused by childhood nystagmus. The poor young doctor in the corner of this slide is trying to understand all about childhood nystagmus. When examining abnormal head posture in a child with nystagmus, it’s important to use as low an acuity target as possible to bring out the abnormal head posture. I use a slightly suprathreshold target that changes every few seconds. I use the M and S acuity machine that does this very nicely, and this tends to demonstrate a fairly consistent abnormal head posture. As we know, there are two main types of childhood nystagmus, so-called infantile nystagmus. This is the early onset nystagmus, seen with symmetric congenital sensory disorders. Such as albinism, optic nerve hypoplasia, also called congenital nystagmus, congenital motor nystagmus, congenital sensory nystagmus. And the other main type of childhood nystagmus, fusional maldevelopment nystagmus, FMN, previously called latent/manifest latent nystagmus. This is the nystagmus that is seen with infantile onset strabismus, and/or an asymmetric sensory disorder. So we have two different types of nystagmus that can cause a face turn. And there is this seminal paper by Dr. Spielman, who gave one of the first Knapp lectures for APOS, and she points out the difficulty and the importance of differentiating these two different types of nystagmus as they cause an abnormal head posture. So we’ll have a look at an example. Face turned to the left. With both eyes closed, there’s no face turn. With both eyes open, there is a face turn. Either eye fixing, there is a face turn. With fusional maldevelopment nystagmus, we’ll talk about that first and have a few examples. This is a nystagmus associated with infantile strabismus. The patient has a bilateral monocular nystagmus. It’s usually horizontal. 25% torsional. Nystagmus with right fixation is not the same as the nystagmus with left fixation. With right fixation, there is a horizontal nystagmus to the right. Plus or minus a torsional nystagmus. With left fixation, there is a horizontal nystagmus to the left. Plus or minus a torsional nystagmus. Blocking the horizontal nystagmus to improve acuity produces a face turn. Blocking the torsional nystagmus to improve acuity produces a head tilt. And we’ll see some examples in a moment. Here is a head tilt to the left, driven by left eye fixing. Torsional fusional maldevelopment nystagmus, torsional FMN, results this fixation in intorsion of the dominant left eye. The dominant left eye recruits the superior oblique and blocks the torsional nystagmus of the fixing eye to improve acuity. It looks like preference for fixation in intorsion. The same mechanism causes right DVD. Face turn. Both eyes closed, no face turn. Both eyes open, face turn to left. Left fixation drives the face turn to the left. With right fixation, there is no face turn. So here we have left fixation. Drives the face turn to the left. And it’s driven by horizontal FMN. Fixation in adduction, face turn to the fixing eye, recruits the medial rectus, and this acts as a brake, and blocks the horizontal nystagmus of the fixing eye to improve acuity. So a patient with FMN will tend to turn the face to the fixing eye. There is a preference for fixation in adduction. This same mechanism causes the dissociated horizontal deviations. Here we have a rather complex situation. Both eyes closed, no abnormal head posture. Both eyes open, head tilt to the left. Left fixation, head tilt to the left. This is probably torsional FMN. There’s a torsional nystagmus. We recruit the left superior oblique to act as a brake. This brake nulls the nystagmus, improves acuity. Left fixation causes this. Both eyes open causes this. So the left eye is the dominant eye. When we force right fixation, this patient has a face turn to the right. This child, this person, had infantile onset strabismus. And the face turn to the right is driven by horizontal FMN. The right medial rectus is recruited to act as a brake. B-R-A-K-E, on the nystagmus, to improve acuity. So here we have a complex abnormal head posture that is fixation-dependent. We’re back to something simpler, face turn to the left, either eye fixing, face turn to the left. If there is strabismus, it can become more complicated. Now, whenever we have any childhood nystagmus with any abnormal head posture, we will often have a convergence null. So if we have a face turn that is being driven by infantile nystagmus, we will often have a convergence null for near. And if we have a convergence null for near, you should now test to see if there is a convergence null for distance. Simple. Add 7 diopters base out with -1 OU. So a total of 14 base out. If this produces a convergence null for distance in the office, the child should wear these glasses in a real life trial for at least a few days. If the convergence null for distance is frequently preferred in a real life trial, we can continue with the prism glasses for years, or we can do a BMR to produce the same effect. So-called artificial divergence surgery. How common is a convergence null for distance? This was — just some results of 88 consecutive eye movement recordings from my practice. And one third of my patients who have mostly idiopathic infantile nystagmus, one third have a convergence null for distance. And the detail with this table suggests that this is probably an underestimate. Also suggests that the PAN estimates are also an underestimate. This is an example. Here is a boy who’s got a pretty complicated multiplanar null, associated with idiopathic infantile nystagmus. He’s got a face turn to the left and a tip up. And base out prism with a little bit of minus demonstrates a convergence null for distance. And at least in the office, he prefers this distance convergence null with a large face turn and tip up. It’s simpler for him to use a convergence null for distance if it’s available. And now he needs to wear these glasses in a real life trial, and if they work well, he can continue with the glasses or have a small BMR. Here is a difficult problem. A patient who has both a face turn to the left and a face turn to the right on different occasions. And there are two main explanations. One of them is periodic alternating nystagmus, PAN. PAN is a variant of idiopathic infantile nystagmus. It’s maybe 25% of my infantile nystagmus cohort. I have no idea what it would be in Nigeria. It’s very underdiagnosed. Some types are easily diagnosed on the history, on the examination, and some types are difficult to diagnose. A phenotypically similar condition is alternating face turn, driven by fusion maldevelopment nystagmus. If the fusion is fairly equal, then the patient may alternate between right fixation and left fixation. Right fixation will be used with face turn to the right, left fixation, a face turn to the left. And this is the FMN driven alternating face turn. And finally, tip up and tip down. These are pretty rare. With both eyes open, and if present, with either eye open, this is a vertical gaze paresis or palsy. This is infantile nystagmus with a vertical null. Or this is one of the pretty rare SCA, spinal cerebellar atrophy syndromes. We have a couple genetic populations in Australia where these are fairly common. I don’t know if they’re seen in your country. In children, tip up and tip down — healthy neonates can be seen with paroxysmal tonic upgaze, paroxysmal tonic downgaze. If it’s strabismic, CFEOM can produce a tip up, thyroid eye disease, tip up or tip down. And if it’s only present with both eyes open, it’s probably an alphabet pattern strabismus, A or V pattern. And that’s all I have to tell you today. Dr. Adio, are you there?
DR ADIO: Yeah. Can you hear me? Can you hear me?
DR KOWAL: I can hear you, yes. I can’t hear you now.
DR ADIO: Now you can?
DR KOWAL: Now I can.
DR ADIO: All right. That was a very interesting one, though a little bit complicated. We would like to ask some questions. I don’t know whether the audience have any questions there. Okay. We have some participants there. Do you have any questions? All right, Lawrence. Another question there. Lawrence, I saw you raised your hand. If you have something to say, you can do that. While we’re waiting, it would be interesting to talk about periodic alternating nystagmus. Yes. Sometimes I see maybe two or three in a month of periodic alternating nystagmus. But what to do with them is the issue. So maybe you can shed some light on what you can do for these patients with periodic alternating nystagmus.
DR KOWAL: Okay. The periodic alternating nystagmus is a subgroup of idiopathic infantile nystagmus. Many of them will be diagnosed on the history. So the parents will tell you — or will show you photos, where three photos show a face turn to the left, and the next ten photos show a face turn to the right. Or it’ll be obvious in your examination. But in children, it’s a little different, to the acquired PAN in adults. In children, it’s the periodicity — is often very asymmetric. It may be five minutes to one side, and only a minute to the other side. And unless you’re watching the child all the time, you will miss it. Or it might be five minutes to one side, and then back to primary. And unless you think of it, you will miss it. If you think of it, then what I think you should do is do the base-out prism test. You put up 7 diopters base out in each eye, with -1, and if that fixes the PAN, then you don’t need to look further. Then it’s PAN with a convergence null for distance. And the prisms will fix the face turn. The prisms will improve the acuity, if the nystagmus is degrading the acuity. And the prisms will enlarge the null zone, and the child will function better. If the prisms work very well, and the child or parent wants the child to be independent of prism, you can do a BMR. I have — when I do the BMR, I’ve always also done —
DR ADIO: Bimedial recession?
DR KOWAL: Bimedial recession. Bimedial recession. The world’s early large experience on this was from France. Dr. Spielman. She always did quite large recessions, and had a low but definite incidence of consecutive exotropia. I have always tended to do small recessions. If 15 diopters of prism produces a convergence null for distance, I’ll only do a bimedial recession of 3. Sometimes that turns out not to be enough, and I’ll go back and do a little bit more. And that’s how I would diagnose and treat PAN. Periodic alternating nystagmus. I’m very lucky in that I have a nystagmus laboratory. And so I have Larry Abel, is in my city, and he just measures — he does beautiful eye movement recordings. But what I’ve described, you don’t need eye movement recordings. Now, I see there’s a question. Explain the treatment modality of infantile nystagmus with abnormal head posture with a null point. I tend to… Is Richard Hertle known in Africa?
DR ADIO: Is what?
DR KOWAL: Richard Hertle? Is he known in Africa?
DR ADIO: Yes, I was going to ask you that. Because he does a lot of nystagmus surgery, disinsertion and reinsertion. I didn’t know what to think about that. Maybe when you answer this one…
DR KOWAL: Well, he is famous for tenotomy resuture operation. And it’s an operation that he doesn’t do very often. The commonest operation that he does are the ones that are Kestenbaum-type operations or Anderson-type operations, or the combination. That’s, I think, they’re the number one and two surgeries that he does. The bimedial recession that I refer to, so-called artificial divergence surgery, and the tenotomy resuture operation is about 10% of his surgical case load for nystagmus. So he will do that in a patient with periodic alternating nystagmus who does not have a demonstrated convergence null. He will do that in a patient with nystagmus whose eye movement recording shows poor foveation time. Unfortunately, you can’t demonstrate that in any other way, other than by eye movement recordings. If an eye movement recording shows poor foveation time, that tells us that the nystagmus itself is compromising the acuity. And if we can improve the foveation time, we may improve the acuity. So that is one indication for doing the tenotomy resuture operation. It’s a very uncommon indication, and is often successful.
DR ADIO: Okay. So for the nystagmus surgery, this person was asking — infantile nystagmus with a null — how do you treat that?
DR KOWAL: I pretty much follow all Richard Hertle’s surgical recipes. And for horizontal and for vertical, I pretty much follow his recipes. I’m not sure about torsion. I tend to do the Lueder surgical recipe that I mentioned in my talk. Greg Lueder. But these are not common.
DR ADIO: Can you explain that Lueder technique?
DR KOWAL: I think you need to look at the paper. On one eye, he disinserts the anterior half of the superior oblique tendon. And on the other eye, he does quite a large recession of the inferior oblique. And that combination fixes the head tilt. I think you need to look at his paper, and you need to follow his recipe as accurately as you can. No one will do many of these surgeries, so you need to, I think, just follow his recipe as perfectly as you can.
DR ADIO: Now, the question says — for infantile nystagmus with a null point, the null point is on the left. How would you do that?
DR KOWAL: Well, if a child has — with a nystagmus, has a null — has a face turn to the left, so they have a null in right gaze, first thing I would do is to see if they have a convergence null for distance. If they have a convergence null for distance with prisms in the consulting room, then I prescribe prism glasses. And I either see them in two or three weeks, or ask the parents to send me photos in two or three weeks with a progress note of how they’re going. If prism glasses are clearly successful, that is a good first treatment. If prism glasses are clearly unsuccessful for any reason, including the desire not to wear glasses, then I would do an operation. And again, I follow the Hertle recipes. Less than 20 degrees, I would just do two muscles. So for a left face turn, I would recess the right lateral and the left medial. And if it’s more than a 20 degree face turn, I would do four muscles. Recess/resect on each eye, using Richard Hertle’s surgical doses. And that’s what I would do. I see there’s another question. When do we opt for surgical management in abnormal head posture? Well, I think there’s two questions there. Maybe nystagmus and not nystagmus. So if a patient has an abnormal head posture that’s not due to nystagmus, you offer surgery if you understand what’s going on. And if you are likely to help that patient. And if the patient — if on discussion with the patient, when you offer your treatment options, the patient finds them attractive. And the third question there: What should be the approach for a general ophthalmologist to be sure he doesn’t misdiagnose any mild abnormal head posture? I don’t think in general a mild abnormal head posture is important. So don’t worry about a mild abnormal head posture. Unless I’ve misunderstood the question.
DR ADIO: I think what the question is trying to find out is: How do you know if someone has an abnormal head posture? What do you do to be able to know someone has an abnormal — because if they come in with their (inaudible), you tell them to read the visual acuity chart, and then if they can see the smaller letter, (inaudible) and you pay attention to — and if they are preverbal, just show them something that is interesting. And you see the abnormal head tilt. When they’re trying to see exactly what… So you can miss it. So the additional thing now is to check whether it’s a visual head tilt or whether it’s not, by adding the patch either to one or the other eye. And then another thing is to tell the patient to lie down. And then also see if the abnormal head posture or the movement of the eye that is abnormal… (inaudible) when the patient is lying flat. (inaudible) and take pictures also. I’m a great believer of taking pictures. I take a lot of pictures (inaudible).
DR KOWAL: Yes. And getting the parents to take photos is very important. Unposed photos, when the child is watching television. Unposed photos, when they’re using their iPad. We have this wonderful international experiment. Billions of children using iPads around the world. And we can do all these wonderful evaluations.
DR ADIO: If they have both a squint and an abnormal head posture, like an ET, esotropia, and then you also have an abnormal head posture… Maybe you have face on, or you have head tilt. Which one would you tackle first? And would that have any bearing on how much dosage you would use for the Kestenbaum?
DR KOWAL: These are very difficult questions, Dr. Adio. Very difficult. Because if you have too many patients like this, you’ll go gray. That’s my explanation for my grayness. No. I did my fellowship in Philadelphia, and one of my chiefs was Dr. Reinke. And this was one of Dr. Reinke’s great interests. He produced lots of tables to modify the Kestenbaum operation for different types of associated strabismus. Fortunately, it’s not a common problem. Unfortunately, it’s often difficult. And you often… I will often try and fix them both at the same sitting. And often successful. Sometimes not. Sometimes need a second surgery. There is no magic to this. There is just… Approach it carefully, discuss it with your colleagues, discuss it with your fellow, and try to produce the most logical operation. If an eye is amblyopic, that’s easier. Because that eye will never be driving a face turn or a head tilt. But it’s just… It’s difficult. There is no easy answer.
DR ADIO: It seems there’s no easy answer for anything. So all we can do is do the examination. You might ask for a second opinion with that patient. But the general advice is to make sure that the abnormal head posture is stable first, before you do the (inaudible) procedure for the patient. What do you think is the minimum or maximum age — minimum would be best — what do you think is the minimum age before you start doing surgery for abnormal head posture? How long do you want to wait?
DR KOWAL: I’m not sure of the answer to that. Dr. Hertle — his answer is as soon as the child is walking. And certainly I have seen children with bad head postures where it seems to have resulted in late walking. And maybe if they had had their head postures fixed earlier, they would have walked earlier and better. Maybe. So Dr. Hertle, who is, I think, the most experienced person in the world… He would say the earlier the better. I’m not sure. I’m not sure what the answer is. I don’t think I’ve ever operated on an abnormal head posture for nystagmus in the first year of life. Or maybe not even in the second year of life. But certainly in the third and fourth year of life. Yes. I have a corridor in my office, and I will ask the child to run to a parent at one end of the corridor, then to run back to me at the other end. And if the child runs with a very bad face turn, or a head tilt, then I will operate. I’ll recommend surgery. And the parent will see that it’s sensible.
DR ADIO: Okay. Okay. So that’s a good one. Because sometimes you get worried. The parents really don’t know what to say. Whether they should wait a little bit and the child is bigger. Whether it will change, and sometimes even in the consulting room, it doesn’t show every time. You know? Or it’s bad sometimes and then it becomes… When you examine more, when the child is paying attention, you see a very bad head tilt — so like you said, it’s manifest most of the time. And affects the child’s quality of life. That should be a good time to do something for that. I think there are some other questions. Somebody is saying that… What else can be done after you have corrected for astigmatism and there’s still residual abnormal head posture? And someone else said… You have a minute or so… What is the Kestenbaum surgery? And then finally summarize the management of this patient (inaudible).
DR KOWAL: Okay. Well… There’s a question: What is the Kestenbaum surgery? I think in the 1950s or ’60s, there were two papers that came out in the same year. One from Australia, by Anderson, and one from New York, by Kestenbaum. On treatment for mostly face turn in congenital nystagmus. As they called it then. And both — the Kestenbaum approach was more aggressive. Recess/resect on each eye. The Anderson approach was recess only. So for your example before of a face turn to the left, the child who prefers right gaze, I would recess the right lateral. Anderson would recess the right lateral and the left medial. And Kestenbaum would recess both of those and resect the other two muscles. And I think it’s a little bit of a degree. The four muscles will have a bigger effect on a big face turn. The two muscles will have a big effect on a small to medium face turn. So I think it’s just a matter of… The bigger the face turn, the more surgical dose you want. That’s the Kestenbaum. A child who still has residual head posture after correcting for astigmatism… If it’s nystagmus, you just… If it’s a face turn, two muscles or four muscles, as I’ve just described.
DR ADIO: We have a lot of albinos here in Nigeria.
DR KOWAL: Wow. Wow.
DR ADIO: Albinos. And they have a lot of nystagmus. It’s a big challenge. You know? Usually we give drops. Azopt drops.
DR KOWAL: Azopt drops? Do they work? Do they ever help?
DR ADIO: It works. Yes, we don’t have eye movement recordings, but I have videos of before and after. Just plain videos. We don’t have eye movement recordings. But we have pictures of eyes moving with very poor foveation times, and then we have recordings of after we give Azopt, and they are still moving, but (inaudible) a little bit more prominent. And maybe doing this recess/resect… Tenotomy, tenectomy…
DR KOWAL: Resuture.
DR ADIO: Resuturing. Might be very important for them. I’ve been a little bit wary. I’ve not done any. But they’re doing well with those drops. But something like (inaudible)…
DR KOWAL: Well, I have used Azopt in a number of patients. And none of them continued to use it. None of them continued. None of them continued. So in my cohort, it doesn’t seem to be that effective. If I had a patient with albinism and if they had a convergence null, I would do a small bimedial recession and tenotomy resuture. And there’s a little bit of a problem with bimedial recession in albinism. The albinos that I see all have a positive angle Kappa. And if you do a bimedial recession, you may bring this to the parents’ attention. Even if you do not produce a consecutive esotropia, the parents may blame the surgery for the positive angle Kappa that has always been there. Do you have positive… In Caucasians… In Caucasians with albinism, we have — they have positive angle Kappa. Do you have this in your cohort too?
DR ADIO: Very few. But I’ve seen it, yes.
DR KOWAL: Very few?
DR ADIO: And in fact, we are warned not to do those on people like that. Those who have positive angle Kappa. If you do surgery for them, it doesn’t work well.
DR KOWAL: So if you do surgery for their nystagmus? Is that what you’re saying?
DR ADIO: Well, the positive angle Kappa…
DR KOWAL: Well, you can’t do surgery for that. But patients who have albinism…
DR ADIO: It’s an ET…
DR KOWAL: They look like XT.
DR ADIO: Yeah. (inaudible)
DR KOWAL: Okay. So… If you don’t have eye movement recordings, if they are straight and if they have a positive response to prism test, and if they wear prisms, and it works, then you should consider bimedial recession. And if they don’t have that, I would think that tenotomy resuture is such a low morbidity operation that I would be… If I had no way of measuring the foveation time, I would still be happy to offer it. It is such a low morbidity procedure. And that would be my attitude.
DR ADIO: So you would do all four horizontal muscles?
DR KOWAL: All four horizontal muscles.
DR ADIO: Okay. Interesting. All right. I think you’ve answered most of the questions now. It we talked about managing. Would you like to summarize finally and then end? The management of AHP?
DR KOWAL: Management of AHP? It’s simple and it’s difficult. You have to approach it logically. You have to ask the question. Is the abnormal head posture — is it definitely driven by vision? Or is it not driven by vision? If it’s driven by vision, is it there only with both eyes open? Only with left fixation? Only with right fixation? Or is it there with either eye fixing? You have to answer those questions before you can understand what’s going on and how to help the patient. That’s the summary.
DR ADIO: That’s the summary.
DR KOWAL: And someone has just asked: Can you please explain the mechanism of the drops for nystagmus? I don’t know that anyone understands the mechanism.
DR ADIO: Nobody. Nobody.
DR KOWAL: No.
DR ADIO: (inaudible) it works in some. It doesn’t work in others.
DR KOWAL: I have another small subgroup of teenagers, adolescents, aged 16 to 20, whose vision is not good enough to get a driver’s license. Here, to get a driver’s license, they have to be 20/40. What is it in Nigeria? Is it similar?
DR ADIO: 6/9, yes.
DR KOWAL: 6/9. 20/40. And I will sometimes use drugs, Neurontin, gabapentin, to get — to improve their vision by a line or two, so they can get their driver’s license. And Neurontin sometimes helps. If a child might have PAN, baclofen sometimes helps. And improves acuity. So these are just in that small subgroup of adolescents.
DR ADIO: Well, we’ve had a very stimulating time.
DR KOWAL: Thank you very much.
DR ADIO: Some interesting questions. Thank you, Dr. Lionel Kowal.
DR KOWAL: Thank you, Dr. Adio.
DR ADIO: All the way from Australia. We appreciate you. Thank you so much. It’s a very complex topic. I’m not sure one hour will do justice to it. There’s still a lot to be read about. There’s still a lot to find out. Even the world’s expert, Dr. Hertle, keeps saying he doesn’t know everything about nystagmus and abnormal head posture. But it’s something we have to tackle as pediatric ophthalmologists. So you are all very welcome to have been with us for the last one hour. And I hope you were not confused and were able to understand some things. Some new information also about how to examine this patient. Thank you very much.
DR KOWAL: Thank you for having me. Bye-bye.
October 6, 2019