Accommodative esotropia is a common strabismus entity. This lecture discusses several variations from the expected findings and clinical course that occur with important frequency. The problems of decompensation, delayed resolution, and the role of bifocals are addressed.
At the conclusion of this lecture, you will be able to manage patients with accommodative esotropia more efficiently and provide better information to patients about the final outcome.
Lecturer: Dr. Edward Raab, Professor of Ophthalmology and Pediatrics at Mount Sinai, New York, NY, USA
(To translate please select your language to the right of this page)
DR RAAB: My name is Dr. Edward Raab. I’m speaking to you from Orbis’s offices in New York, where it’s a nice warm morning. Thank you for joining us. I realize that our audience is from a lot of different places. And it comes at different times of your day, and probably competes with something important to you. So we’re very happy that you chose to be part of this. Our subject for this morning is accommodative esotropia. And you probably saw that this lecture was titled accommodative esotropia and its complications. Now, the complications are really not what we really think of as complications, as we might from a surgical procedure. Complications — I could have used a better description. Because it really talks about departures from my experience, from what is most often taught about accommodative esotropia, and how to manage it. So think of complications in that sense. I’m gonna try to point out to you an experience of mine that made it, in many ways, easier to manage these patients. And for those of you who practice in environments where patients have difficulty coming for follow-up, can’t afford glasses, or other kinds of treatment, anything that would shortcut and not compromise care would probably be valuable for you, and we’re gonna try to get to some of those. And I’m sure you’ll recognize what they are. So the first thing to do is to talk about the usual description and definition of accommodative esotropia. You all know that it’s an overconvergence in response to a neurologic stimulus that demands accommodation. In order to see clearly, both at distance and at near. And all intermediate distances. And we have to start by talking about something that we call the linkage of accommodation and convergence. We can induce convergence without accommodation by using graduated powers of base-out prism. And that would force convergence, without necessarily affecting accommodation. We cannot stimulate accommodation without also stimulating convergence. So stimulating convergence doesn’t necessarily bring out accommodation, but accommodation does bring out what we call accommodative convergence. And that linkage is typically described as the AC/A ratio. So accommodative esotropia really has two major classifications. One of them is the demand for accommodation, in order to see clearly, when optical correction is not provided, is normal in amount, but the linkage to convergence is in favor of a very high convergence response to what might be a very normal need for accommodation. So that’s one classification. The high AC/A ratio type of accommodative esotropia. The other type is based on excessive hypermetropia. Now, there the linkage between the accommodation stimulus and the convergence stimulus might well be normal. However, the demand for the accommodation is great, unlike in the previous group, where the demand is normal, but the response is excessive. Now, it is possible to have in the same patient elements of both problems. Now, the AC/A ratio can be derived as a number, but the number really doesn’t help us. It’s a concept. It’s a concept based on a clinical substitute that we use as the distance-near comparison. No one really measures the AC/A ratio, even by the so-called gradient method, where you judge the patient’s convergence response as you put up minus lenses, in order to induce a certain amount of accommodation. The reason it’s never really measured is that we are measuring the relationship between innervational stimuli and not so much the responses. So unless you found a way to put electronic sensors on both the accommodation arc and the convergence arc, you’re not really measuring the AC/A ratio. So don’t think of it as an important number. Think of it as a concept that — as a useful substitute, we use the comparison of distance in alignment based on the difference in accommodative demand for distance and near. Now, there’s one other variety of accommodative esotropia that very few people talk about, and you don’t see talked about much. And that’s probably an overlooked problem. It has to do with some individuals who — even putting out normal accommodation innervational stimuli don’t respond, except in a very diminished way. Now, a good example of this in everyday practice would be a patient with cycloplegia. When you induce cycloplegia, the patients may try to accommodate, even when they can’t. This would put out additional accommodation stimulus, neurogenic stimulus, and the convergence linkage would kick in, and they would overconverge. So that would cause extra effort. In which case it acts like increased hyperopia. And also, the extra effort would make it like the AC/A ratio, because the accommodative demand at close range is greater. Now, another example of hypoaccommodation, not only cycloplegia, would be the aphakic patient. Aphakic children can have accommodative esotropia, when they don’t have intraocular lens, or they’re not wearing their contact lenses or spectacles, they still try to accommodate, especially at near, without having an organ of accommodation. The lens. So that’s the same as what happens with the cycloplegia. So accommodative esotropia based on hypoaccommodation is a third variety, and much more difficult to treat, because the hypoaccommodation cannot be increased, and therefore they could have a very prolonged, if not lifelong clinical picture of accommodative esotropia. We may find it important, in patients whose accommodative esotropia does not disappear after a certain time to check their accommodation amplitude. Because if their accommodation amplitude is diminished, then they fall into this hypoaccommodation group, and your treatment will not be successful. Either as completely or as rapidly as if they are not just functional hypoaccommodators. So now let’s start with a question. I haven’t given you the information. This is really a survey to see how the audience thinks. And when you see the answer based on my response, you might have to adjust your own thinking. So let’s take a moment to look at the choices. Should I read it to them? Okay. So why don’t we cast our votes? Here are the results. Those of you who thought that accommodative esotropia typically begins prior to age one year — only 6% of you. At 13 to 18 months, 19%. At 2 to 3 years, 69%, and at 5 to 6 years, 6%. 2 to 3 years is the correct answer. And that’s choice C. So most of you got that. The typical age of onset is between 2 and 3. However, a small percentage actually do occur prior to age 1 year. And another small percentage at 13 to 18 months. Original onset at age 5 to 6 years, unless it’s a child who’s been made aphakic by removal of cataracts, for instance, is unusual but possible. Because those cases are unusual, the onset of accommodative esotropia at those ages are uncommon. So here are the result of two studies. One of them by Dr. Marshall Parks, who I’m sure just about all of us would recognize as the great-great-grandfather of pediatric ophthalmology. And here’s a child under age 1, and you can see there’s obviously a crossing of the eyes. This is not congenital esotropia. The child was straight until the age of about 10 months. At which time the eyes became crossed. And you can see that putting on the appropriate glasses straightens that. So a small percentage will be present by age 12 months. And most at age 36 months. And the point here is to show you that, whether the AC/A ratio is high or normal, this same distribution of age of onset occurs. So there is not a predilection for one or another type. The two types that we discussed — or even the third type, hypoaccommodation — to occur differently, based on age. So here, again, is the result. Age 2 to 3 years was the correct answer. Based on my experience, and that of a very well recognized senior member. Now, here’s something that I always assume, when I encounter a case of accommodative esotropia. Because it is not like congenital esotropia, where the eyes are crossed almost immediately after birth, in many instances, the onset, even for those who have it in the first year of life — they have a very early period, where the eyes are straight. Either because they don’t exert their accommodation, because their visual demand doesn’t require it, or because their hyperopia is simply not high enough that early — and so I make the assumption that if their eyes were present early in life, even for a matter of months, they have the visual system capacity for binocular vision with fusion and stereopsis if their management gives them that opportunity. Every strabismus, based on correcting misalignment, does not put capacity for one or another sensory result in a patient’s system. It gives them the opportunity to develop and exert what nature has already given them. In this case, I assume optimistically that they will fuse, and may even have stereo, with appropriate treatment, early enough. And that’s usually before age 6 or 7 years. So now, when we talk about the two types, the high AC/A ratio and the normal AC/A ratio with high hyperopia — and it turns out, both in Dr. Parks’s reported study and in mine, that statistically, each group is responsible for about half of the occurrences of accommodative esotropia. We have to modify that a little bit. These two studies were not done when hypoaccommodation was taken into account. Maybe 5% of cases are due to the hypoaccommodation response that I mentioned before. So the remainder, the high AC/A and the normal AC/A, where accommodation is normal in those patients, it’s just the convergence is abnormal — they are roughly split half and half. The difference in percentages here are not statistically different. So now we have another question. Does accommodative esotropia tend to decrease with age? That is, the AC/A ratio? Does it decrease with age? Does it decrease with surgery? Does it decrease with orthoptics? What is the cause of the decrease of the AC/A ratio, when it occurs? So let’s take a second to respond to that. Okay. The responses are… 77% of you said that the AC/A ratio, when it changes, will decrease with age. 15% say it will decrease with surgery. 8% say it will decrease with orthoptics. So let’s discuss that. The AC/A ratio does tend to decrease with age. Nothing really increases the AC/A ratio, unless, again, the cycloplegia question, and the aphakia question might do that. But typically, if the AC/A ratio changes, and it doesn’t always, it will be a decrease, and age will do that. Surgery — especially recession, weakening of the medial rectus muscles — will also do it. Orthoptics does not do it. Orthoptics may improve fusional amplitudes, but does not change the AC/A ratio at any age. So A and B were the correct answers. And then this is based on not only my experience, but that of Dr. Parks. And most others who have considered this question. All right. We talked about the AC/A ratio. Let’s talk now about hyperopia. Now, again, whether the AC/A ratio is high or normal, the distribution of refractive errors is fairly typical. The normal AC/A ratio — the ones that cross because of the excessive accommodative demand — have a hyperopia and cycloplegia — for Dr. Parks 4.75 diopters, for my study, just about 4 diopters. Those are comparable. And for the high AC/A ratio, where the linkage is what’s disturbed, and it’s the convergence that’s high — the typical refractive errors under cycloplegia were under 3 diopters. And those are statistically significant differences, if we were to apply an analysis to that. And I’m sure this is well known to most of you. Okay. Now I’d like to do — diverge and talk about: How do we do cycloplegic refractions? Which is a very important element of the management of accommodative esotropia. So let’s start with what drug. The general world seems to favor atropine. Atropine is a long-duration cycloplegic. It begins and reaches maximum intensity at about 20 to 24 hours after first instillation, and can last about 7 to 10 days, during which time the patient is grossly incapacitated without the glasses, compensated hyperopia. So atropine, in my practice, is not useful for any patient with accommodative esotropia. The reason atropine is considered better than cyclopentolate, cyclogyl, is that the cyclopentolate may not bring out the maximum cycloplegia. That’s because many people refract after giving the drop too soon. Giving cyclopentolate and refracting 20 minutes to half an hour later will miss the maximum effect, which comes out between 45 and 60 minutes. It is routine for me, and most of the time my office schedule gets backed up, so that I have no trouble following that routine — to do the cycloplegic refraction after cyclopentolate after about an hour. Now, Dr. Parks, the same doctor we’ve been mentioning, his study was where he used atropine in order to make patients accept their glasses when full strength hyperopic corrections were being rejected for blur. He would have the patients use 1% atropine once a day for 10 days, having done a cycloplegic refraction, and based his prescription on that. And he found that after 10 days, of atropine, the cycloplegic refraction was not different than the office refraction, after one hour of cyclopentolate. So that atropine doesn’t really do a better job, other than the fact that it’s generally used more appropriately. Now, the regimen, if you’re going to use atropine, well, let’s talk about the regimen for cyclopentolate. I usually give 1%, not 2% cyclopentolate, with or without phenylephrine, in order to increase dilation, but not cycloplegia. In order to get a better orthoscopic exam. But I give 1% cyclopentolate, one dose, repeated in 5 to 10 minutes, with the refraction done about an hour later. With atropine, the standard recommendation is three times a day for three days, and once again on the morning of the examination. Well, the drop given on the morning of examination doesn’t do anything to supplement what’s been given for the previous three days, because the maximum effect of that will not come about until the following day. So there’s no point giving that one. Three times a day for three days will induce toxicity. Especially in younger, fair-skinned children. If I’m gonna use atropine, which, as I told you, I never do, — what you hear in the background is a fire drill. Sorry for that. I hope you can hear me anyway. If I was using atropine, I would use it twice a day for two days, and omit the dose on the same day of the examination. That would limit toxicity and probably give — I haven’t studied this — but I expect, based on the pharmacology of that drug, would give you the result. So that covers how often to use it for both of those drugs. The only time I would use mydriacyl, which is a weaker-acting cycloplegic, would be for the much older patient, who’s been in very good control, and is approaching teenage, and I am probably in the process of diminishing or reducing their dependence on glasses. So the main drug for me is cyclopentolate. All right. Here we have another question. And let’s see what your opinion is on this. What happens to… We talked about the changes in AC/A ratio. Mostly diminishing. What about in hyperopia? Does it begin to decrease from whatever the original level is? Does it begin to increase from the original level? Does it increase from the original level and then decrease later? Or does it tend to remain the same? So let’s hear your opinions about that. All right. Has everybody cast their votes? Here are the results. Those who said there was a steady decrease from the original level — just about half. 48%. For those who said it continues to increase after the original level, 3%. For the increase from original level followed by decrease, 39%. And for those who said no change, 10%. So let’s see. My experience is — and it’s been confirmed by other studies — is that whatever the level, high or low, of hyperopia — we’re not talking now about those who start out myopic — but those who start out hyperopic, at whatever level, there’s an increase up to about age 7 years, and then followed by a decrease. The increase from the original level, up to age about 7 years, puts you on guard that you have to follow with refractions the level of hyperopia, in patients whose control on the most recent prescription you gave them may not be any longer complete. The decrease, after about age 7, is important, because that’s when we can start lessening the well-controlled patient. We can lessen the amount of their hyperopic correction, because their hyperopic requirement is decreasing. That is why I put that question in there. Because it bears on our management in two stages of a particular patient’s condition. And here’s the backup for that. My study was based on several hundred patients. The study of a Dr. Brown — and this is a different Dr. Brown, for whom Brown syndrome is named — found the same thing. In several thousand refractions, the initial increase from age 1 to 7 years was about the same. About 2/3 increased, and then about a quarter decreased, and only a small percentage remained the same. So the correct finding is that about 2/3 to 3/4 increased before they decreased. And we only, on our question poll here, had 50% of you feeling that way. So I would urge you to test your own results, and your own patients, and see whether or not you might want to revise that. Because it’s important in your management. Okay. So now we know about the AC/A ratio, and how it changes. Now we know about hyperopia, and how it changes. So let’s translate or implement those into our treatment. My treatment of a new case of accommodative esotropia is to eliminate all the accommodative effort, initially, by giving the full cycloplegic correction, as determined — if you like by atropine. For me, it’s by cyclopentolate with an interval of an hour before refraction. When I show that a patient can be well controlled doing that, later on, particularly after age 6 years, as we saw in the previous slide, we try to taper to eyes that can stay straight or have only a small esophoria within 10 prism diopters, let’s say, with the least hyperopic correction we can do. Obviously if they have astigmatism at the same time, we want to maintain the astigmatic correction. When control is maintained stable, that’s when we look at repeating refractions. There’s a great tendency here in my country, in the United States, to tell doctors managing accommodative esotropia whether or not the patient’s controlled, to follow the cycloplegic refraction every 3 to 6 months. I have found that to be totally unnecessary. If the patient is well controlled on the prescription I have given them, I have no reason to care, particularly, whether his hyperopia is increasing or decreasing. When I’m trying to taper the patient down, and use the least hyperopia correction that I can, I also don’t care what his cycloplegic refraction is? I will taper him down, even if for some reason the hyperopia is still continuing. Because the goal is to have the patient rely on the least treatment you can supply. You want to have them expand fusional divergence, not with orthoptic exercises, necessarily, but just in the conditions of everyday viewing, where if they’ve been tapered down to a very small esophoria, you want their fusional divergence to build up within their own visual system, to compensate that. So for me, usually I don’t repeat the refraction and the dilation for anywhere up to two years in the controlled patient, and part of that is because I do think they should have another ophthalmoscopic examination, and I only depart from that rule and do it more frequently when I think it’s unstable, and it may be because I haven’t adequately kept up with the hyperopic demand. Now, the other way to treat is with anticholinesterase miotics. Which have largely fallen out of favor, at least in the United States. They may be a useful substitute where patients live far away, and don’t have access to glasses — especially for changes of glasses. But where those are not the problems, anticholinesterase miotics, for me, have not been helpful. The advantage is that you can use them in infants instead of glasses. I’ve shown you a couple of illustrations where infants have tolerated glasses, even bifocals, very well. Another advantage, it’s said, for anticholinesterase miotics is that you can control at intermediate distance, not just at far distance and at near. And you can do this without bifocal. That’s probably true, but it doesn’t really override what I consider to be the disadvantages, which I will get to in a minute. The supposed advantages — they’re not advantages, in my view — is that if you have a patient that you’ve examined, looked at their hyperopia, and are not sure that they’re really accommodative esotropia, you can give a trial on miotics for the case that you can’t make a firm decision. Now, the trouble with that is: The effect of anticholinesterase miotics is not as reliable as glasses that are properly accepted. So to make up your mind about the indeterminate case, you would do it with a miotic with less than the best evidence. And for that reason, I think it’s only a supposed advantage. And then of course there’s a compliance issue. Parents will tell you: My child simply can’t wear glasses. All right. You might say let’s try miotics. The problem with that is… You’re gonna have the same compliance problem with the miotic. The child is gonna object to drops or ointment instilled. And the parents are gonna give in to that. So when you have compliance problems, you’re not dealing with the children anymore. You’re dealing with their guardians and caregivers. A firm hand on the part of the parent or the adoptive parent or the caregiver is what you need to overcome compliance problems. The child doesn’t have a vote in how he’s treated, any more than you gave the child a vote as to obtaining immunizations. If they needed vaccination or other immunizations, they got it. They weren’t asked their opinion about it. And the same thing should be true here. All right. Now, there’s no information on this slide. I have this slide to introduce the topic of bifocals. How important are bifocals? Well, whether we give bifocals, if we’re not using miotics, as I recommend you don’t — we give bifocals in the high AC/A ratio type, or the high distance-near comparison type of accommodative esotropia, and we also would in the hypoaccommodation group, which is very small. We typically don’t need it in the high hyperopia group, because their AC/A ratio is normal, and their distance-near comparison will reflect that. But we need bifocals at near because the accommodative demand at near is even greater for distance. We all know that. And so one strength of spectacle is not going to take care of that. We need a bifocal. There are those that say if the eyes can be made straight for distance, it doesn’t matter if they are still esotropic at near. And I don’t like that reasoning. I don’t like it because if you’re treating the distance because you want straight eyes, why not under all circumstances? Why only under some circumstances? Particularly when, the younger the child, the more their visual activities are based on the visual world at near. They’re not driving cars, they’re not going to movies, they’re not looking at street signs. Why should they be allowed to overconverge at near, when you find it necessary to eliminate their overconvergence at distance? So the reasoning for that I don’t understand. And there was a debate about this, which I participated in, at the American Academy of Ophthalmology subspecialty day a few years ago, in which I gave that argument for bifocals. So now let’s talk about one of the so-called complications, which is really not a complication. It’s an adverse secondary result. Decompensation or deterioration is when you have a child who has been controlled on optical treatment or miotics, bifocals or not. But now is no longer straightened merely by discouraging accommodation with those measures. When there is decompensation, that becomes a surgical problem. And the goal is to restore straight eyes not by eliminating the accommodative element, but only the part that’s no longer regarded as an accommodative element. That is to say, doesn’t respond any longer. In most cases, except in teenagers or adults with persisting accommodative esotropia, if you substitute surgery for non-surgical treatment that discourages accommodation, you will have a large percentage of secondary exotropia. So that’s one of the so-called complications. The rate of decompensation is anywhere, depending on the study you read, 11% to 48%. My own particular rate of decompensation, as you see here in this slide, was 17%. And it turns out… Well, I’ll give you the answer. The turnout will be based on question four. Who is more likely to decompensate? The high hyperopia cases with a normal distance-near relationship? The high AC/A with an increased distance-near relationship? Or is it the same in both types? So take a second to cast your vote about that. Okay. I only gave you three possibilities. So we shouldn’t be taking too much time to do that. Here are the findings. 25% of you said that the high hyperopia cases are more likely to decompensate. 61% of you said that it’s the high AC/A ratio cases. And 14% of you said it doesn’t matter what the AC/A ratio is. Either one is prone to decompensate Within the range that we talked about. Well, here’s the answer. In my experience, and that included 106 patients with a normal distance-near, and 87 with a high distance-near, there was no statistical difference between the rate of decompensation and the overall rate, as I showed you in the previous slide, was 17%. So only the minority of those who responded picked this point. And I would encourage you to go back among your own patients and see whether — and I would be happy to hear from you about this by personal communication — whether you concur in what my experience is, and also if you concur about what happens to hyperopia with time. So the answer is… It was the same in both types. Again, I encourage you to scrutinize your own experience in this, and to let me know what it is. Okay. So now we’ve talked about accommodation — decompensation of accommodative esotropia. And our next complication, if you want to call it that, is: What about those that don’t go away after 6 or 7 or 8 years? Well… Here’s my study on this. I found that slightly more than half were still present by age 10 years, despite the fact that their hyperopia typically is expected to decrease at that age. And that 29% were still present after 12 years. And I had a few patients in whom it never disappeared, even into childhood, and these were not aphakic patients, or those on extended cycloplegia. So you may have to deal with some accommodative esotropia persisting forever. And dependent on optical compensation. Okay. Now, here’s another study I did. This is important to those of you whose patients have trouble complying either by coming to see you or by obtaining — because of the cost — of what you prescribe. Let me diverge a minute to say that I recognize two types of non-compliance. There’s what I call willful non-compliance. Who are those? The ones who don’t care to follow what you tell them, the parents who give in to their children who don’t want to wear glasses or take drops. That I call willful non-compliance. The other type of non-compliance are those who just can’t afford to be treated or afford to show up. That’s really too bad. For those patients — not for the other group, who just don’t do what you want them to do — here’s a study that may help you. Or simplify your treatment. So I did a study on my own patients to see if we could reduce the number of visits without lowering the quality of care. I was brought up that to follow even well compensated accommodative esotropia — every three months. And what I found while doing that was, if I compared my notes from three-month visit to three-month visit to three-month visit, I found I wasn’t doing anything different from one visit to maybe the fourth visit down the line. And in the well compensated patient, that was usually a visit to start decreasing their compensation. So what I found was… That I would not miss any decompensation that would require surgery in patients who I got controlled. If I controlled the patient well, with the initial treatment, with the initial spectacle treatment, which is what I typically used, and they came back in 6 to 8 weeks, and I could see that they were well controlled, I could let them go at least a year without seeing them again. Because very few of them would decompensate. None in the first year after successful treatment. Only 2 out of 54, which is about 4%, at 18 months, and only about 12% at 2 years. So you might say: Well, what if you wait two years, and you miss some decompensation, and you haven’t done timely surgery? Well, it would be nice to do timely surgery. But even if you waited two years, and a few had decompensated in the mean time, restoring their compensation, especially because they had a period of time either before they became accommodative esotropes, or for a time after you successfully treated them, they had normal binocular experience at a young age, so that they can recover. So if you can’t for logistical and cost reasons see your patients as frequently as every 3 months, I would tell you it isn’t necessary when your first treatment led to a successful result at the 6 to 8 week post-treatment visit. You can safely let them go at least a year, and if you had to, even two years. I didn’t have enough patients to include the further data, but I can tell you that the same result continues beyond that. So my conclusion from that study was: Most patients did not require a stronger treatment in the first two years after control, providing they’re controlled. If they require stronger control, they’re not more likely to decompensate if you delay providing it. And it doesn’t matter if these were early onset cases or late onset cases. Age was not a risk factor for decompensation. I think those are very important clinical points. Especially where patient access to you and access to the appropriate treatment may be limited, for reasons that neither they nor you can control. So what I recommend from that is that after — again, it depends on whether they were controlled at the 6 to 8 week visit after you gave the treatment. The next exam, at age 9 to 12 months, or even later, is sufficient, and does not compromise quality of care. Are there exceptions? Yes. If you’re treating amblyopia at the same time, you shouldn’t let a patient under amblyopia treatment go for two years. Their regimen may be needing readjustment. If you’re dealing with coexisting vertical and oblique muscle overactions, they may have vertical deviations, where that precludes fusion. So even if their eyes were horizontally okay, when they look just a little bit to either side — I’m not talking about mild overactions, but substantial overactions — you probably would want to monitor those more closely. And if it’s a patient on miotics, you want to monitor for any side effects, such as iris cysts or tags or — it is said that they’re prone to retinal detachment. That turns out, in children, not to be particularly true. Okay. We’re almost at the end. And then we’re gonna take some questions from you, if you’ve been writing them in. Accommodative esotropia typically exists by itself. But it can exist with other conditions. Like Brown syndrome, that I think you know about. Duane syndrome. And also congenital nystagmus. It is not strictly a separate entity. Okay? It also can occur after surgery for infantile esotropia. Congenital esotropia. A child, 6 months old. Operated. Nothing to suggest intermittency. Or that the patient at that age is really exerting all the accommodation they need. They can be straightened, and later on develop accommodative esotropia, as though they hadn’t had any surgery previously. It isn’t that you didn’t make the correct diagnosis. This is a consecutive appearing deviation. And you have to watch it, especially if the hyperopia increases. It’s not so much about the initial hyperopia. But the increase. That’s a group you might follow with more than every two years’ determination. After surgery for intermittent exotropia, some patients, about 7%, will have a persisting overcorrection that has an accommodative element to it. Now, you can’t do anything about that, because intermittent exotropia requires, for the best result, an initial overcorrection. Most of us would agree to that. But you should warn parents about it. As you should with anything. With any strabismus case. When you’re doing surgery. That there is probably a need in about — anywhere from 10 to 30% of cases, for one reason or another, to require more surgery. So here I just want to show you about Brown syndrome. Look at the upper pictures. The patient has, in the downgaze pictures, nothing to suggest an anomaly. In the upgaze pictures, there’s a big divergence in straight upgaze, number B, and a bilateral Brown syndrome. Inability to elevate the abducted eye. If you look below, here’s the same patient, and guess what? The esotropia she has is accommodative. Didn’t get rid of the Brown syndrome, but she has accommodative esotropia. I have a report in the literature of three such cases, and I’ve seen three or four more. In Brown syndrome. Several more in the intermittent overcorrection that I or other people got, and several more in the nystagmus cases. I think that we’ve come to the end of it. So now we can consider any questions that you might have put in. So I’ll read the question. And give you the answer. Here we have one. When the high hyperopia is detected for the first time and glasses given, the children will not be comfortable. In these children, do you give home atropine eye drops, along with the glasses? The answer is I do not do that routinely. I do that if there’s evidence that the child is rejecting the glasses or wearing them but reporting blur. And it can be done with home atropine, or even atropine — or even cyclopentolate. And here’s another question. How much amount of hypercorrection do you induce for cyclopentolate and atropine? I’ve already answered that I give full — whichever cycloplegia you’ve used, in the beginning, I want to get rid of all the accommodative overconvergence, and so I give the full amount. And another viewer asks: How much do you reduce glasses, and what are the intervals after 7 years? Well, when they come into the office, it isn’t based on a cycloplegic refraction. When they come into the office, wearing their glasses, and they’re over age 7, and they’re well controlled, I’ve tested them for some fusion and for stereopsis. You may even want to see if they have fusional amplitudes. You don’t have to do that. You can presume that they have them. What I do is I put a trial frame up over their glasses, and I put in, to start with, -75 sphere in both sides. And then I check again, to see if they have not a phoria, but a manifest esotropia, with a cover-uncover test. If they don’t have a manifest esotropia, then I test them for phoria. And if I get a phoria of somewhere around — no more than 10 to 12 prism diopters, and they’ve been straight with a cover-uncover test, I give them a new prescription, reducing the sphere by that amount. Now, I may even carry it further, to see what they do if I put in a -1.5, to see what they do. But I don’t do that, because I don’t need that information, because I don’t, at any one sitting, reduce it by more than 0.75. Okay? And at what intervals do I do that? Going back to the other question… Dr. Parks used to do it very frequently. He would do it at three-month intervals. The logistic question for me, about whether they can afford so many changes, or whether they can get to me, if they’re coming from a long distance, I tend to do that more like every six months. And I always tell the caregivers: You don’t have to change the frame. Even if you do, make sure you keep the old lenses, because in doing this, if it turns out we’ve done it a little too much, we may have to go back to the previous ones, and you can save some money by saving the previous glasses. So here’s another question that says: The cycloplegic drugs at different ages? No. My routine is for atropine — almost never. Except to get them used to the glasses. And that’s not for determining the refractive error. Cyclopentolate at all ages, except at maybe teenage or adulthood, I would depend on tropicamide, mydriacyl. So here’s another question that says good morning. And I return your greeting. Good morning. Which miotic can be prescribed in these cases? It used to be DFP. Diphenyl fluorophosphate, which has to be compounded, in order not to degenerate — decompose. So that was expensive, because it had to be put up in peanut oil or similar. Nowadays you can use anticholinesterase miotics — phospholine iodide. I don’t use it very much. The only time I really use it is if a patient comes to me, having been treated by another doctor, is already on a miotic, and although I told you the miotic is not reliable, if the patient on the miotic is not showing side effects, and is correctly compensated, I don’t change them to glasses. I would continue them on miotics. So now here’s another one that says… For a two-year-old kid with accommodative esotropia, the cycloplegic refraction is 2 diopters hyperopia, and that controls the distance ET but at near, it requires a +3 add to correct the near. Can you prescribe +5 single vision for a child who will not use bifocal? I wouldn’t do that, because he’s going to reject the +5 for distance. So he’s now gonna reject the glasses for a different reason. I would give the bifocal, as you indicated in your question. I would see them in 6 to 8 weeks. And if the report is — or if you ascertain that they’re not using the bifocal — that’s when you can give them a 10-day course of atropine, 1%, once a day for 10 days. That’s how Dr. Parks discovered, if you remember, that it wasn’t necessary to use for cycloplegia. But then if you give them that for 10 days, they will depend on the near deviation, because they’ll have a very big blur, even wearing their +3 for distance. And as the atropine is stopped and then weans off slowly, the idea is that they will continue to use the bifocal. So I will not advise giving the +5 just for the bifocal, because they’ll reject for other reasons. Now, the question: What is the mechanism for increasing hyperopia in the initial 7 years of life? Based on repeated cycloplegic refraction. No other way that I know. Instead of bifocals, do you prescribe progressive? Well, of course, progressive is a bifocal. It’s a multifocal. The answer to that — in a child, I don’t. I would like to see where the junction is. It should be prescribed with the junction at midpupil, and as a flat-top bifocal. Typical or optical dispensing is that if you have a plus correction, they will give a dome-shaped bifocal. Whereas what you really need is a flat-top. And usually I would either give a progressive — in which it’s all the way across — or I would give a flat-top 35 millimeter width, W-I-D-T-H, 35-millimeter wide segment. And in either case, you specify in the prescription the junction is to be at the midpupil. Some people say the lower border of the pupil. I say midpupil, because the glasses tend to slide down the child’s nose, typically, and you want to make sure that it’s up high enough so that they can be used without extreme downgaze. So I would not use progressives, because you never can tell what the patient is using, if you don’t see the junction. Obviously when they’re older and well controlled, and you can rely on their compliance, you can go to a progressive. So here’s one that says: After you do cycloplegic refraction, do you do subjective refraction in another visit before prescribing? And the answer is no. They will either adapt to it, or with the use of an atropine course for 10 days, they will adopt to it. I’m not interested in giving them less. I want to give them the full amount. I anticipate that it will ultimately be fully accepted. So I don’t cut it, and therefore I don’t need a subjective refraction. The other is: How much of an add in case of bifocals? Again, if I’m starting to knock out all accommodative esotropia, I would give them a full +2.50 or +3. When later I’m trying to reduce the correction, I would separately use the -0.75 over the distance correction and over the near, and you may find that you have to diminish it differently whether it’s the upper segment or the lower, and so the — how I do it is the same. But I would do it at near with the -0.75 with the bifocal portion. For infants, what would be the concentration of cyclopentolate? Under 6 months, which you won’t typically be using, I would probably use 0.5%. Anything over 6 months, I would use 1%. I would not use 2% at any age, because it gives psychological side effects, which are not desirable. And can generate fevers, and aberrant behavior. And so I prefer not to use 2%. The time to start using glasses… Decrease the chance to keep good stereo? Yes. The later the treatment, the less of the chance. However, if the onset was late, and they had long experience with straight eyes, then that wouldn’t diminish the chances. Only if it’s neglected or lately started… You know, tardily started treatment, that it would be that. What about pilocarpine as a miotic? Yeah. It doesn’t have the same effect as phospholine iodide, but you can use it that way. With at least two instillations a day. I would give it morning and not at night, because you don’t care for the effect overnight. I would give it morning and mid-afternoon, for instance. And that would cover waking hours. Is accommodative esotropia related to all three types of Duane’s syndrome? I can’t answer that. I have too few cases to answer that, and I wouldn’t look at it that way. I wouldn’t see why it should relate to the type of Duane’s syndrome. Next? Okay. We are at 10:00. And so I think we have to stop. Anybody whose questions we didn’t get to, I’m sorry. If you want to email me personally, can I state my email address for them? It’s eraabmdjd. That’s J for John. eraabmdjd, with no dots in the middle of that and no capitals, at aol.com. And I would be very happy to answer these or any other questions, if you forward them to me. And I have been very happy to share this hour with you, and I hope that I’ve given you some personal insights that may depart from what you see in textbooks, and that may be helpful in your practice. So I wish you a good day, or evening, for the rest of what you have today. For me, it’s gonna be the rest of the day. Thank you, and goodbye.
June 23, 2017