October 01, 2004
18 min read
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Round table: Amblyopia studies changing pediatric ophthalmic practice patterns

Part 2 of a pediatric ophthalmology round table also included discussion of techniques for treating adult strabismus.

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MODERATOR

Robert S. Gold, MD
the Pediatrics/ Strabismus Section Editor of
the Ocular Surgery News Editorial Board,
is in private group practice in Longwood, Fla.

Brian J. Forbes, MD, PhD
is a member of the division of ophthalmology at Children’s Hospital of Philadelphia and an assistant professor of medicine at the University of Pennsylvania School of Medicine in Philadelphia.

Scott E. Olitsky, MD
a member of the Pediatrics/Strabismus section of the Ocular Surgery News Editorial Board, is the ophthalmology section chief at Children’s Mercy Hospital in Kansas City, Mo.

Marc F. Greenberg, MD
is in private group practice, specializing in pediatric ophthalmology, in Atlanta.

Naval Sondhi, MD
a member of the Pediatrics/Strabismus section of the Ocular Surgery News Editorial Board, is a clinical professor at Indiana University in Indianapolis.

Anthony P. Johnson, MD
a member of the Pediatrics/Strabismus section of the Ocular Surgery News Editorial Board, is in private group practice in Greenville, S.C.

Robert S. Gold, MD: The second part of our discussion will be an update on treatment for amblyopia. The studies of amblyopia treatment performed by the Pediatric Eye Disease Investigator Group are moving along fast and furiously. There may be controversies about study design, and certain protocols may need to be adjusted, but there is no question that because of these studies, in my practice I have looked differently on the treatment of amblyopia and become much more flexible in that treatment.

I’d like to first talk about one of the studies that was presented at the American Association for Pediatric Ophthalmology and Strabismus meeting this year. The study investigated the recurrence of amblyopia after patching or atropine had been stopped.

Let me just review a few of the statistics. This was a prospective study, not randomized. The protocol was either 6 or 2 hours of patching or atropine. The study investigators found that 25% of the patients had recurrence of their amblyopia within a year. There did not seem to be a difference between the atropine and the patching groups. The study authors suggest that, if the patching was done for 6 hours, and the patching was not weaned but totally stopped after a certain period of time, there was a greater incidence of recurrence, over 40%. If the patching was weaned from 6 hours to 2 hours, there was less than a 15% chance of recurrence. If the patient had patching for 2 hours and the patching was discontinued, there less than a 15% rate of recurrence.

I’d like to know what everyone does in their practice clinically, either similar to this study or not similar, so that the readership can see what different clinicians do. Would you start, Naval?

Naval Sondhi, MD: To put it briefly, the study found that patients who had undergone patching less than 6 hours a day, if they were taken off the patching or the atropine regimen, did not regress as often as children that received more intensive patching.

That’s been my practice in the past. I used to wean most patients off, but I did that when patching was the primary occlusive method or primary treatment method that I used for treatment of amblyopia.

I have started using atropine a lot more than I used to, and I still stop that pretty quickly, and after the end of the studies I may yet change my practice on that.

My patching occlusive treatment varies based on the cause of the amblyopia. The strabismic amblyopes I start patching at the first visit or as soon as it is diagnosed. The anisometropic amblyopes, on the other hand, I always start them out just with glasses and follow their progress with time, and if they either do not improve or the improvement stops at some point, I initiate the occlusive treatment.

My practice has always been to treat those patients with a minimum amount of patching because my experience has been that they respond nicely with minimal patching. I find that strabismic amblyopes require a little bit more patching.

Given the recent studies that Dr. Gold referred to, my personal treatment or practice has been modified somewhat. I do not patch as aggressively as I did. The maximum I do is what I call 80% patching. In other words, I give at least 2 hours a day off, irrespective of the level of amblyopia.

I would have to say I think my results today have been better or equally as good as my previous treatment regimen.

Brian J. Forbes, MD, PhD: I often tailor my amblyopia therapy based on the age of the patient. If at initial presentation the child is 4 or 5 years old, regardless of strabismic or anisometropic amblyopia, I always start with glasses and usually treat with glasses alone until the visual acuity levels off.

There’s no question that the work by the Amblyopia Treatment Study group has largely changed the way I treat amblyopia. I come from a training program where full-time patching was the rule, part-time was certainly not, and I’ve gone from full-time patching for even moderate amblyopia to 2 hours with great success. I’m sure my patients appreciate it as well.

In the older children, I often initiate therapy after a single visit. I don’t wait for visual acuity to improve with glasses.

As far as weaning, I’m still intimidated by those few patients that I see in my practice who are 12 years old, and I discontinued treatment when they were 9 or so, and they lost lines. So having known these results for some months now I do wean patients more aggressively, but I think our role is to do close follow-up.

Marc F. Greenberg, MD: I was glad to see this study presented because I think the question of who to stop and how to stop clinically in practice, when you’re in your office, is much more important and much more of a question in all of our minds than how to treat the amblyopia. Amblyopia treatment can be done many different ways. There are many ways to skin the cat, and it doesn’t really matter how many hours you’re prescribing a day. It doesn’t matter if you prescribe 6 hours a day or 4 hours a day.

One of the things the amblyopia treatment studies have shown us is that the people at home do different amounts of patching anyway. But your end result is not how much they are patching; your end result is their vision. In all cases, no matter what style of occlusion you use, if the vision is not getting better, you are going to increase it. Your endpoint is equal vision in both eyes, no matter what method you are using. So that is an easy one.

But once you have gotten the vision back, what do you do now if you have a 4-year-old or a 5-year-old patient? The parents have put a great deal of effort into gaining that vision, and no matter what you told them, they’ll always forget, and they want to know when they’re going to be finished.

We all have had patients for whom we’ve stopped therapy, or they’ve stopped on their own, and they have done fine. And we’ve all seen people slip back. I don’t think anyone anywhere in pediatric ophthalmology today knows exactly which patient in the chair is one who is likely to regress. We don’t even know who is more likely or less likely. We don’t know that answer, so that’s a great question to be investigated.

Scott E. Olitsky, MD: I primarily look at two things: how good the vision is in the once-amblyopic eye and how straight the eyes are. In a patient whose vision in the two eyes is equal or nearly equal and whose eyes are straight or nearly straight, I discontinue patching completely. I find that those patients have a fairly low incidence of recurrence. But I also know to follow them closely. If they do have a recurrence, I can get that vision back, and as much as I like full-time patching in the treatment of amblyopia, I don’t want to patch people who don’t need to be patched.

I explain to the parents at the time of discontinuation that there is a chance we may have to restart patching, but I don’t wean them. I stop, and I let them prove to me that they need more patching once their vision is equal. And I agree with Marc. This is an important question because while we want to keep vision equal, we also don’t want to patch people who may not need it.

One of the things this study did not answer, which was asked, was whether it is the amount of patching or the level of vision that the patient achieved that correlates to the recurrence of amblyopia. Hopefully, we’ll look at that in the future.

Anthony P. Johnson, MD, FACS: I try to get the vision equal by patching less aggressively than I did at one time. I am glad to see these Pediatric Eye Disease Investigator Group (PEDIG) amblyopia treatment studies come out, because it validates some of the things I have found as I have decreased the amount of patching to try to maintain or improve patients’ compliance.

It is interesting to look at the regression rate in these studies. I have seen several patients who come into the practice when they are 8 or 9 years old, and they were previously patched, and now they are 20/200. We are not exactly sure what was done, but it’s clear that some effort was placed to treat these kids, and they’ve lost ground.

So in my practice, once I get the vision equal, I will taper down to either 1 or 2 hours a day and patch them until age 9, rigidly. I stop the patching at age 9. If they are anisometropes or accommodative esotropes, I will continue with glasses on a full-time basis. I will see them in 3 months. If they have not lost ground, I’ll see them 6 months later, and then over the next year or 2 years eventually go to yearly checks.

Now with the regression data in this study, it makes me wonder if I should be following them more closely until they are 13 to 14 years old.

Dr. Greenberg:The question of when to stop amblyopia treatment really gets to the heart of what is amblyopia. Why can one child stop patching and his brain continues to use both eyes together, while another child stops patching and the brain unplugs those neurons again?

It’s the question of how did it all start. In some very young children, 6 months of age, say, with a large refractive error, we do the 4-D prism test, and if they don’t seem to have amblyopia at that time, at least by fixation, I’ve given a number of those children glasses and they never did develop amblyopia.

So when exactly does it occur, and when is it cured? When is it reversed? We don’t really know the answer to those questions.

Dr. Gold: Regarding age, I think the PEDIG investigators are taking it to the next level. They are studying children from 7 to 17 in studies to be reported in the future, and hopefully they will be able to tell us more. How long should we go? Who should we go with? It’s exciting for pediatric ophthalmology to have a group delving into those questions.

Dr. Greenberg: It seems we haven’t defined who falls into those categories, the people you can stop patching and the people you can’t. But on a neuromolecular level there’s something different between those two categories of patients. With the patient that you can stop patching, it is not the treatment, it is not that you did better patching or faster patching. It’s not that you treated their amblyopia better and that is why you can stop. There is something different about that individual vs. the individual who regresses when you stop patching.

Dr. Olitsky: I agree, and I think that is a critical thing to look at. We all know those patients recur with a fair amount of frequency, but it would be fantastic to know that this patient is different from another patient, and we’re done with his treatment and he is cured. Not better, but cured. Hopefully we’ll know that with more studies.

Dr. Greenberg: I believe it was Dr. Sondhi who suggested that stereoacuity is a good predictor that you can stop the patching. I believe it probably is. I ran an informal study in my office over the past year, to test that. Normally in my practice I tell everybody that they need to maintain patching because I do not know if their child is one of those people that can stop. It’s up to them if they feel lucky and want to stop. I know some people can stop patching without a recurrence, but I have to recommend to each family that they continue patching.

But over the past year I have changed that, especially in the families of anisometropic amblyopes with good stereoacuity. I offer them a second pathway, suggesting that we can just check again in 3 months, realizing that we might have to start patching again, but that their child seems to be a good candidate to stop the patching altogether. And just about everybody took me up on it. But some of them did regress, and they had perfect stereoacuity, 20/20 in both eyes.

Dr. Sondhi: That really needs to be looked at closely. Is the refractive amblyope different from a strabismic case? I don’t think it’s 100%, but they may be predisposed to a different result.

Dr. Greenberg: I had another impression that I looked at in my office. It seemed like the patients who had vision come back very fast might be the best patients to offer a trial to stop patching.

In other words, certainly for patients with moderate to severe amblyopia I am going to recommend near full-time patching. But if they came back at the first visit with equal vision, I thought maybe they were in a different category. It might be that those patients had something different about them, that their brains hadn’t truly started to ignore the eye in the same way as some other patients. In other patients it took 6 months of patching, and it got a little better each time they came. In those patients, I thought, if I take away their patch it’s going to get really bad.

So I tested that, and again I had some that recurred. They came back to 20/30 or 20/20 the first time I saw them back, and then we stopped the patching, and it went back to the way we started. I think maybe that is a better category for lower risk of recurrence, but I still had some recurrence with them.

Adult strabismus

Dr. Gold: One other topic we want to cover today is adult strabismus. A paper that was presented at the AAPOS meeting this year had to do with outcome contributors in adult strabismus patients, and there was discussion of what the authors termed “value-based medicine.” Can we define what is meant by value-based medicine as it applies to adult strabismus in our practices?

Dr. Greenberg: Value is measured by the person doing the measuring. Ophthalmologists are being asked to justify the value of our treatment to insurance companies and third-party payers, and what they value is sometimes different from what we value. They don’t necessarily value stereoacuity or field of binocular vision. But they do value patient happiness. A lot of times those go hand in hand, but they don’t always.

Dr. Gold: I know some of us in this round table don’t treat adult patients, but let’s discuss some of the specific conditions that we see in our offices or clinics that would benefit adult patients in having strabismus correction.

Dr. Johnson: In my practice, adult strabismus probably takes up about 5% of my time, or perhaps less. The most challenging adult patients, the most frustrated patients that I see, are those with thyroid eye disease. I see probably 12 or 14 severe cases a year, patients who have already had bilateral orbital decompressions when I see them, and they almost all have severe restrictive eye muscle movement disorders. They range in age anywhere from their 40s to their 80s, and it’s amazing to me the span of the age group. Depending on age, they often require two, three, four surgeries, and I find that they are very unpredictable. Sometimes I can’t help them at all, but once they are functional they are the most grateful patients.

Dr. Olitsky: I think certainly there are few physicians, patients or third-party payers who would argue with the fact that the patient with diplopia is somebody that we can help, and that’s a fair percentage of the adults that we treat. Where we really need to be advocates for our patients are with those patients who do not present with complaints of diplopia and who come to us with needs other than visual needs. Those are the patients we can all talk about regarding value. We have had problems with insurers asking why they should be covering their surgery.

Dr. Gold: Are you talking about those that have had either decompensated type of strabismus problems or consecutive strabismus problems from previous surgeries when they were children? Or sensory strabismus issues? Would you like to open up that discussion?

Dr. Olitsky: I think many of those patients, unfortunately, never get a chance to see us because often they are erroneously told that nothing can be done for them. What that patient is being told is, “We can’t help with the development of binocular vision, or improve your vision, or get rid of your double vision, since you don’t have any.”

They are told this is “cosmetic,” which is a word that is used too frequently and should probably be stricken from the record in these patients. And two things may occur. Patients are sometimes reluctant to admit that they want to look normal – not better, but normal. And the referral isn’t made by the person seeing that patient because they don’t feel that they will get any functional benefit from surgical treatment.

Dr. Gold: So if there are people that want to come to you, but they may not get to you, how then do we then discuss what we can provide for these patients? How do we say that we can provide functional benefit for these adult patients that have significant strabismus problems in their daily lives?

Dr. Greenberg: There is no question that we are doing reconstructive surgery and not cosmetic surgery. Reconstructive surgery is done for looking normal, for not wanting fingers pointed at you. Cosmetic surgery is done when you want to be better than normal, when you want fingers pointed at you. The finger-pointing analogy usually works, and people understand that.

In our hospital, we have not had a big problem with being reimbursed for reconstructive strabismus surgery. It’s not like cataract surgery, where if the insurance company cut it out they might save a fortune, but of the few patients that we recommend, almost always we have it done.

Dr. Olitsky: I agree with that. It hasn’t been so much third-party payers. Unfortunately, it’s been other eye care professionals who prevent the patient from coming to us because they are told that they can not be helped.

Dr. Forbes: I don’t treat adults, but I would agree with Scott. I frequently see the parents of children who obviously had strabismus that runs in the family, and the parents have significant cosmetically bad strabismus. Initially I was bashful about asking, but now I ask, “Why don’t you go get the test,” and almost universally the answer is that they have tried to get the test and they were told it’s not offered to them.

Dr. Sondhi: I would like to reiterate a point that you made earlier, to emphasize it. There are functional benefits of strabismus surgery in adults aside from those with diplopia. I entirely agree that diplopia is something that can be tested, felt and measured. Some of the other benefits either are not quite so easily measured or are not routinely measured but certainly can be. Binocular fields and so forth.

So it really needs to be emphasized that this is reconstructive surgery. I like that term. I have not used it, but I will in the future. And I think it behooves us to educate the physicians that these people seek counsel from before they get to us, that these people can be helped.

Dr. Johnson: One thing that is intangible, hard to measure and hard to discuss – and especially hard to discuss for other eye care providers if they’re not interested in it – is the concept of re-establishing peripheral fusion. No matter what the patient’s condition is – amblyopia, a macular scar, there are a variety of things that would prevent them from having good central vision – if you can re-establish their peripheral fusion, their alignment is going to be much more stable after a long, long time.

You can’t really measure the benefit of peripheral binocular function. It is just something that can not be measured. But I tell the patients that the reason for doing this is only if it’s bothering you, the patient. If it’s bothering the patient, it is not cosmetic. It’s functional. The hard part for us is to measure that functionality.

But in our area, we have really not had that much trouble, once the patients get to us, if they’re seeking the help. I can’t think of any case recently in which the insurance company impeded their ability to be helped.

Dr. Olitsky: I agree wholeheartedly with that. I would also say that even patients who have no hope of increasing their binocular dilatation, even if they are completely blind and it is deviated, they still benefit from having their eye straightened. I am sure we can all tell stories about patients who come back and not only feel better, but have gotten a job interview or feel like their place in society is better. I think there is actually evidence out there that shows that. This is information that we need to pass on to other providers.

Dr. Gold: Another issue is what anesthesia techniques we use for adult patients. What approaches are you using?

Dr. Greenberg: I think there is more variability in surgical technique, and there is also better anesthetic technique for adult strabismus.

We started a few years back using propofol sedation with local anesthesia for easy to moderate adult strabismus cases. We use lidocaine with epinephrine, injected with a blunt cannula in the initial snip incision on the conjunctiva. I infuse with a blunt cannula under the belly of the muscle prior to starting the case, after they’ve been sedated.

It is a lot easier on the patients, and the turnaround time is incredibly faster. Since I started doing that, I also started operating in an ambulatory surgery center, which is even more right for that type of treatment. The patients are often able to leave 20 minutes after surgery, and they are not sick or vomiting. I think that’s been great.

Dr. Olitsky: In my adults who are interested, and many of them are, I also perform surgery with a local anesthetic, usually with a sub-Tenon’s infusion, if I am operating in only one eye. I have found that to be a useful technique, and patients are comfortable during surgery.

Dr. Johnson: I am fortunate to operate in an ambulatory surgery center with terrific anesthesia and rapid turnaround times. I have not been confident that I can keep them comfortable with local anesthesia. The turnaround time, the postop nausea, vomiting, all that sort of thing has not really been a problem. I have watched what Marc is doing, and I admire what he’s doing, but I have not taken that approach yet.

Dr. Sondhi: I agree with Dr. Johnson again. I have operated in an ambulatory center. It is an efficient situation with excellent anesthesia, somebody who works with me 50 weeks out of 52. The turnaround time is just not a question at this point. I do probably 99% of my cases under general anesthetic.

Dr. Gold: Since it is two and two, I will break the tie here. I also do the great majority of my cases under general anesthesia. Again, this is because of the comfort with the anesthesia that I have in my area and in ambulatory surgical settings. And part of it is my comfort level as well.

Adjustable sutures

Dr. Gold: It is interesting to come to the AAPOS meetings and hear how much adjustable suture surgery is done. In my practice I do minimal adjustable sutures. If I do, when I do them, I adjust that day, about 4 to 5 hours after the procedure.

Dr. Sondhi: I am not a big fan of adjustable sutures. I have tried them, and for various reasons, when I looked at my own data, I have largely abandoned doing them. When very rarely I use them, I will adjust the same day, generally within 1 or 2 hours. I do that in the recovery room.

Dr. Johnson: I previously did a fair amount of adjustable sutures. Like Dr. Sondhi, after looking back, I didn’t think I gained a whole lot. I saw several patients who were fairly uncomfortable with it. The rare time that I do it now, I do it in the office, not in the operating room. I do it in the office within 3 or 4 hours after the procedure.

Dr. Olitsky: If you do a few, I do fewer. I do none. I have not been convinced from the literature that it is a helpful technique. I hear people talk about those patients, multiple re-ops, who might benefit. But in my experience those are the patients who are most uncomfortable, and they’re probably the least predictable where I want them to be.

I can also say that I have seen many patients who look relatively poor a few days after surgery, and I am concerned a subsequent surgery will be needed, but they come back 6 weeks later and they’re straight. So I worry that I might have adjusted myself out of a good result in those cases.

Dr. Greenberg: It is probably not fair for this panel to go on any further. I don’t use adjustable sutures at all, and I think this panel is probably not completely representative of what is going on in the community. Dr. Olitsky mentioned the literature, and the literature does seem to support using adjustable sutures.

However, once again, the differences in adult strabismus and technique are almost matched by the differences in the types of patients. Any adult strabismus study is difficult to compare to others because all of us, I am sure, have extremely different populations of adult strabismus. If one surgeon is doing thyroid patients and another is doing a patient with a sixth nerve palsy and another doing a fourth nerve palsy, they are all very different and have different success rates. And so it’s difficult to compare one to the next.

Dr. Gold: I will wrap this up by saying that, just like anything we do in our practices, there’s more than one way to do it and more than one technique to do it. That’s what makes pediatric ophthalmology interesting. Whether you do adjustables or you don’t, whether you do general or local anesthesia, it’s your own personal comfort level that hopefully will lead you to the best result for your patient.

For Your Information:
  • Robert S. Gold, MD, can be reached at 225 W. State Road 434, Suite 111, Longwood, FL 32750; 407-767-6411; fax: 407-767-8160; e-mail: rsgeye@aol.com.
  • Naval Sondhi, MD, is a clinical professor at Indiana University. He can be reached at Midwest Eye Institute, 201 Pennsylvania Parkway, Indianapolis, IN 46280; 317-817-1333; fax: 317-817- 1331.
  • Anthony P. Johnson, MD, FACS, can be reached at 131 Commonwealth Drive, Suite 390, Greenville, SC 29615; 864-458-7956; fax: 864-458-8390.
  • Scott E. Olitsky, MD, can be reached at Department of Ophthalmology, Children’s Mercy Hospital, 2401 Gillham Road, Kansas City, MO 64108; 816-983-6730; fax: 816-855-1793; seolitsky@cmh.edu.
  • Marc F. Greenberg, MD, can be reached at 5445 Meridian Marks Road NE, Suite 220, Atlanta, GA 30342; 404-255-2419; fax: 404-255-3101.
  • Brian J. Forbes, MD, PhD, can be reached at Children’s Hospital of Philadelphia, Philadelphia, PA 19104; 215-590-4315.
References:
  • Repka MX, Holmes JM, et al. Amblyopia Treatment Studies. Workshop presented at: Annual Meeting of the American Association for Pediatric Ophthalmology and Strabismus; March 29, 2004; Washington, D.C.
  • Beauchamp GR, Black BC, et al. Patient and provider perspectives on the severity of adult strabismus and on outcome contributors. Paper presented at: Annual Meeting of the American Association for Pediatric Ophthalmology and Strabismus; March 30, 2004; Washington, D.C.