Round table: More to patching duration than PEDIG study suggests

A major study found that 2 hours of patching per day is as effective as 6 hours for moderate amblyopia. But practitioners say other factors must be considered in setting a patching regimen.

Robert S. Gold, MD: We’re going to discuss the recently published article “A Randomized Trial of Patching Regimens for Treatment of Moderate Amblyopia in Children” in the Archives of Ophthalmology from the Pediatric Eye Disease Investigator Group, or PEDIG.

The objective of this study, according to the abstract, was to compare 2 hours vs. 6 hours of daily patching as treatments for moderate amblyopia in children younger than 7 years of age. This was a randomized, multicenter trial with 35 sites. It enrolled 189 children younger than age 7 who had amblyopia of between 20/24 and 20/80, and they were assigned to receive either 2 hours or 6 hours of daily patching combined with at least 1 hour per day of near visual activities during the patching.

To determine the outcomes, visual acuity was measured after 4 months in the amblyopic eye. The conclusion was that when combined with 1 hour of near visual activity, 2 hours of daily patching produced an improvement in visual acuity that was similar in magnitude to the improvement produced by 6 hours of daily patching in these children.

One of the reasons we convened these members of the pediatric section of the Ocular Surgery News editorial board was that one of our members, Scott Olitsky, reported getting some interesting phone calls after the publication of the study. Scott, can you describe what occurred in your practice when the article came out?

Scott E. Olitsky, MD: The study was reported in the local newspaper in the Kansas City area and on the evening news, and the following day I received three or four phone calls from parents about the patching that they were doing. What they took away from the news bulletin was that you don’t have to patch very much anymore to get the same benefit. I tend to be a full-time patcher, so when parents saw that 2 hours of patching worked equally well, they wanted to know if we could move down to 2 hours a day instead of patching all or most of the day.

Dr. Gold: Did you change any of the patching regimens in these patients? How did you discuss that with the family?

Dr. Olitsky: I did not change what I was doing. I explained to the parents that I had some concerns about some of the aspects of the study, what it purported to say and what I think it actually said. I told them I was not really a fan of 6 hours of patching anyway, so that even if 2 hours was the same, it wasn’t being compared to the way I would prefer to patch my patients. I said my feeling was that full-time occlusion would give them a better benefit, or at least a faster benefit. The study looked at a 4-month duration, and I was hoping that in most of the cases, for the parents I spoke to, our patching would be completed in weeks instead of months.

Roberto Warman, MD: I think that’s the main issue here. If you have good, compliant patients and parents with whom you do patching full time or most of the day, you can get them down to a maintenance level of maybe 2 hours a day rapidly, maybe after the first month or at most 2 months. That’s before the child gets tired of the patching.

If you have patients that are not compliant and you tell them to patch 2 hours a day, if you’re lucky you’ll get half an hour. If you tell them 6 and you get 2, at least the study tells you that’s helpful to a certain degree. But those patients are going to need at least 4 months of patching, and I’d rather get the bulk of the problem solved in the first month or so.

Anthony P. Johnson, MD: I have found over the years that a small number of full-time patching patients, especially the ones that were densely amblyopic, 20/200 or worse, would be so disenchanted that I was losing patients. They were so disillusioned that they would just quit altogether. They were totally noncompliant at that point. Therefore, through no real science, I had evolved into doing little full-time patching.

I used to be a full-time patcher, and I see all the merits of it. The speed with which you can recover vision I think is irrefutable. But I have also found basically what this study demonstrates, that with less patching you can still get results. I don’t know if it’s because it’s easier for me, or because I feel like I’m making it easier for them, but I have been a fan of less patching and have seen results.

But it does take longer. They have to realize that they’re going to be on at least maintenance patching until they’re 9 years old. The benefit to them is that, as long as they’re making headway, they feel the benefit of that, and they don’t feel they have to patch all day.

Dr. Olitsky: One of the benefits of the study is to show that with compliant patching, people get better. I like to strike while the iron is hot. When the patient comes in at 20/80, I like to show the parent a dramatic improvement 3 weeks later.

I feel that they really buy into it. The parents feel that, “We’ve made a huge difference in a short period of time, and I’m willing to patch some more.” My concern is that at 2 or 3 months, if they’re seeing maybe one line change each time they come back, they may burn out before they get to their best level of vision.

Dr. Johnson: I’ve found that if you’re patching a smaller number of hours, it becomes paramount that they never miss a day. I tell them that if they miss 1 day, it erases the last week’s worth of hard work.

If you’re doing full-time patching, there’s really no reason to miss a day, but if they do miss a day I don’t think they lose ground nearly so quickly.

Social stigma and compliance

Dr. Gold: The study authors gave the parents a questionnaire after the first 5 weeks of the treatment. They found a decided concern with the social stigma of wearing a patch in today’s society.

This, of course, is the 2- vs. 6-hour treatment, but this also can apply to full-time patching vs. three-quarter time patching. What is your practice experience with this? Are you flexible enough to change if you feel a patient will have this social stigma concern?

Dr. Olitsky: No, I tend not to be. I tend to find that it’s not a big problem if you don’t raise it as a potential problem.

I do see a number of patients who have failed maybe from a compliance problem with part-time patching. When I ask the parents then to go to full-time patching, they tend to cringe. But I explain to them that in many ways it’s easier because there’s no wiggle room. The child has no time where he gets to say, “I don’t want a patch.”

Almost universally those parents come back and say patching all day was easier than trying to struggle with which 3 hours we were going to have the patch on. I think the therapy goes faster, and sometimes if you don’t bring up issues or give children excuses, they tend not to find them.

Regarding the concern for social stigma, that might be a child I would switch to atropine, but it’s not a child I would patch less. If it’s a real impediment, and the child could be penalized, I would probably switch to atropine.

Dr. Johnson: I have found sort of the reverse of what Dr. Olitsky mentioned. In the occasional patient that I started with full-time patching, often when they move to less patching I find they have more trouble because now they have a choice of what part of the day to patch.

Dr. Warman: There’s another issue. It all depends on what the patient presents. It’s not appropriate to make a blanket statement that 2 hours of patching will work with every situation.

If I get a patient that’s orthophoric with 20/40 or 20/50 vision, I often start them patching after school. They patch from 3:00 to 8:00, say. This isn’t a high number, it’s not full time. But I’m not too concerned. Those patients are probably going to get better anyway, and if they were anisometropic, the glasses by themselves are going to help.

If they are esotropic, even if it is a small-angle esotropia, suppression is deep, and I still think you need to hit hard with aggressive patching at the beginning if you want to reverse this.

Dr. Gold: I have found in my practice, a clinical practice in the Orlando, Fla., area, that many of my patients are not compliant with full-time patching, despite my drilling it into them that they must do this. So I’ve become more flexible in trying to get some compliance, whether it’s 6-hour patching or 2-hour patching. In my practice, the 2-hour schedule is new. Because of this study, I have done it to see whether in my own practice this will work.

I’m being much more flexible, listening to the families carefully to get as much patching as I can from the patient. Whether it’s going to be half the time, 6 hours, 8 hours, 4 hours, I try to maximize as much as I possibly can.

I also have them keep a log and bring it into the office so that I know how much patching they’re getting, the number of hours. If they come in after 6 or 8 weeks and they’ve patched a certain number of hours and the child has not improved, I have numbers there that can tell the family, “You’ve got to do more. If you don’t do more, there’s a good chance the child is not going to get better.” It’s right on paper in black and white.

Near vision tasking

Dr. Gold: The study called for patients to do 1 hour of near work during the patching treatment. Does anyone have a comment on that?

Dr. Johnson: We all see patients and their siblings come in, and it’s not uncommon to see 10 or 12 electronic Gameboys in the office with the kids’ heads buried in them. So I would say, whether it’s a near task with reading or with an electronic game or some other computer application, I think these patients are doing a lot of near activity.

This raises a question. It is important for them to be doing this to get the best benefit, but at the same time it’s hard to control this in a study because so many of these patients are doing near tasks anyway.

So, first, I don’t think it’s an onerous task to ask them to do this near work, and second, the majority of them are doing way more than an hour’s worth of near task anyway.

Dr. Gold: The PEDIG group had this to say about near work in their article:

“Our results must be viewed in the context that in addition to patching the sound eye, the parents of the patients in both groups were given a common instruction in clinical practice: to have the child perform near visual activities for at least 1 hour that the patch was worn each day. We do not know whether performing near visual tasks during a portion of the occlusion time contributed to the improvement in visual acuity of the amblyopic eye or whether the observed improvement in acuity resulted from occlusion alone. We are not aware of any published studies that have prospectively evaluated whether performing near visual activities while the sound eye is occluded is beneficial in the treatment of amblyopia, although benefits have been reported in retrospective studies and case series. We are planning a randomized trial to address this issue.”

Dr. Warman: There was a period of time, before any of us in this room were in practice, when they were simulating this with the Cambridge Vision Stimulator and other similar devices, without actual patching, just simulating near work, and patients improved.

As Tony said, most of these kids are doing near work when they’re patching because that’s what they do. Even watching TV, they probably are on top of the TV anyway, and if they’re patching in school they’re doing near work, and if they are playing around with their Nintendo, or if they’re younger and they’re coloring, they are all doing some near activities.

We all tell them to do that. I think it’s good, and I think it does work. I’m not sure that we really need to do a randomized study to prove that.

Dr. Olitsky: I was going to say somewhat the opposite. I guess I’m not convinced.

I don’t know why we might assume that doing something at near will stimulate the fovea or the cortical cells any more than watching TV from a distance or being outside. I don’t separate those activities as being different, and so I don’t make a special mention to patients about doing near work. I tell them whatever time the eye is open and they’re awake is good patching time.

As was mentioned, the near activity was used in both arms of the study. So as far as this study is concerned, I don’t think we can say anything about that.

Limitations, final comments

Dr. Gold: Let’s have a round of final comments.

Dr. Olitsky: I think a couple of other factors limited this study.

One was the endpoint at which they looked at the data, and that was at 20/32. I imagine most of us in our office would not be checking vision at that level, so a lot of these patients who did not reach that level might be 20/40.

If you look at the patients who achieved 20/25 or better vision, it would appear that there was a difference between the two groups. With 6 hours of patching, there were more patients who achieved 20/25 or better vision. I’m not sure why the study picked 20/32.

Another factor is that the study went for 4 months, not to the best vision they could obtain. So we really don’t know that the two arms are equal because we don’t know how much better each group might have gotten. It may be that one would have continued to get better and the other didn’t. So that limits what we can say about the endpoint as far as best obtainable visual acuity.

So I’m not sure we can really say that both ways of patching are equal. All we can say is that at 4 months out they both appeared equal to a level of 20/32, which may not be the vision we’re looking to get.

Dr. Johnson: One other comment I would make about patching less time, these patients don’t have to be seen quite as frequently. This is easier on them, especially families traveling from farther away to come in for the visits.

However, the reverse of that is true with full-time patching. You have more frequent visits early on, and then you get to the maintenance level more quickly. So at least, assuming that you’re having rapid results, at least they are coming during the time that you’re having frequent visits. Those are the times when parents can feel that they’re having to come in too frequently. We risk the reversal of the amblyopia if we let them stay away too long.

So there is some advantage with the less frequent visits for the patients that are doing less patching.

Dr. Warman: In the younger kid, closer to 3 or 4, I tend to do partial patching. This is, first, because then I don’t have to see them so often, and second, because I think I have time. If I don’t see enough response I can always increase.

Then again, if they are really esotropic I may be more aggressive because I’m concerned about deep suppression compared to orthophoria.

But if I get a child, 6 years old with 20/80 vision coming in for the first time, I’m going to follow what Scott Olitsky says and strike while the iron is hot. I don’t have too much of a chance. I want to hit hard.

It doesn’t matter what the study says, I will continue to try aggressive patching at the beginning. I’m not worried about reverse amblyopia, and I am worried that I won’t get what I want if I don’t start soon.

Dr. Gold: All four of us individualize every patient. You can’t go by exact rules and regulations. You have to treat the way you feel is best for each patient, and not necessarily follow the study exactly. You follow your own convictions and your own clinical experience to make the patient best. I think all of us will agree with that.

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.
• 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.
• Anthony P. Johnson, MD, can be reached at 131 Commonwealth Drive, Suite 390, Greenville, SC 29615; (864) 458-7956; fax: (864) 458-8390.
• Roberto Warman, MD, is an associate professor at Bascom Palmer Eye Institute and Miami Children’s Hospital. He can be reached at 3200 S.W. 60 Court, Suite 103, Miami, FL 33155-4072; (305) 662-8390; fax: (305) 661-7862; e-mail: rwarman@eyes4kids.com.

Reference:

• Repka MX, Beck RW, Holmes JM, et al. A randomized trial of patching regimens for treatment of moderate amblyopia in children. Arch Ophthalmol. May 2003;121(5):603-611.