Dr. Freeman: Welcome to PracticeUpdate. I'm Paul Freeman, Co-Editor of the Eye Care site on PracticeUpdate. I'm an optometrist at Allegheny General Hospital in Pittsburgh, Pennsylvania. It's my pleasure today to interview my very good friend and colleague, Dr. Len Press. Len is a developmental optometrist with a consulting practice in Lakewood, New Jersey, and is Editor-in-Chief of the journal Vision Development and Rehabilitation. Today, we're going to talk about the treatment of amblyopia. Welcome, Dr. Press.
Dr. Press: Thanks, Dr. Freeman. It's good to be with you.
Dr. Freeman: It's good to be with you as well. Let's start by answering a question maybe that a lot of people have. Most people consider amblyopia to be a lazy eye. Is that a reasonable description?
Dr. Press: I'd agree that that's what most people call it in the vernacular, but I don't actually feel it's a very good description, for a couple of reasons. One is that when you say "lazy eye," it almost makes it sound like it's the person's fault to some extent, that if they wanted to see better through that eye, they could. That's certainly not the case. It's totally involuntary.
The second reason I don't think it's a good descriptor is that it implies that the problem is with the eye. What we know through current research is that the problem is just as much, if not more so, in the brain than it is in the eye. So, if you wanted to call it a lazy something, you could just as soon call it a lazy brain. There are other reasons why I don't think it's a good descriptor that we'll probably get into.
Dr. Freeman: Yes, that makes sense. So, I know that when I came into practice in the '70s, the primary... way that we looked at amblyopia treatment involved patching the better eye. Is that still kind of the current thought processes? Are there other things we think about when working with an amblyope?
Dr. Press: Very much so other things. The practice of patching the so-called better eye to improve vision in the fellow eye came about because most people looked at amblyopia as a one-eye phenomenon, that the fellow eye was perfectly normal, which we know now not to be the case. In amblyopia, the relatively better eye isn't entirely normal either.
But the biggest difference is that we now understand that amblyopia really is a binocular phenomenon. In other words, the issue resides in the conflict between the two eyes. It's not a one-eye problem. Therefore, patching the better eye, which is punitive, doesn't really make much sense. Because all the while you're patched, the brain doesn't have the opportunity to integrate both eyes better. All it knows is when the conflict is totally eliminated, then the eye that's poor can perform better. But as soon as you take the patch off, the brain says, thanks very much for the try, but I still don't know how to integrate both eyes well, so over time, I'm going to slide back. So you have these ebbs and flows, you patch, things get better, you un-patch, gradually you slip back where you came from.
Dr. Freeman: Well, let me ask you this then, despite the patching issue, does it make sense or is it important for somebody who's amblyopic to wear their glasses? Does that benefit the patient?
Dr. Press: Very much so. We know now through what are called PEDIG studies, the Pediatric Eye Disease Investigator Group, that the single most important thing, in most cases of amblyopia, is to wear the appropriate prescription. So, even in what's called strabismus amblyopia, which is about half of the cases, where one eye tends to misalign relative to the other eye, and there's also the need for prescription glasses to see more sharply, wearing the ideal prescription that helps you see the best that you can see and integrate both eyes as well as can be done is more important than anything else, and in some cases, is more the key to success than patching. Patching has all kinds of compliance issues.
If you were a young child and an adult came along and said, "I have this great idea, we're going to punish you so that when you put this patch on, you're in a fog. But when you take the patch off, everything seems fine." You probably would say, I think there's seriously something wrong with the way these adults are thinking.
Dr. Freeman: That makes some sense.
Dr. Press: Above all, we should really reinforce that it's not only wearing the glasses [that is] a crucial component of success, but even after the child has improved, it's almost like a retainer after you've had braces. Don't think just because things have gotten better, "Okay, we're done." The glasses are very important for maintenance as well.
Dr. Freeman: Right. So I know, again, going back to when I first started practice, there was a thought that there was an age after which amblyopia therapy would not be effective. Is that the current thinking now? Has the thinking changed since the '70s?
Dr. Press: The thinking has changed. We used to call it a critical period for the development of binocular vision or a deterrent to amblyopia, and that's really a misnomer. There may be sensitive periods. Perhaps you could have a true critical period, let's say a child born with a cataract in one or both eyes. Then it's critical to address that within the first year of life. If you don't, you're going to have all kinds of complications that are irreversible. But absent that extreme case, in most cases, it's never too late to treat amblyopia.
So, there isn't a window that closes at around age 7 or 8, as we used to think. Granted, when you get older, it's harder to get as good an outcome as you could get at a younger age. But as a wise patient said to me, many years ago, "Doc, you don't have to make it perfect, you just have to make it better."
Dr. Freeman: Well, that's good information. Do you have any last-minute thoughts you want to share with those who are listening?
Dr. Press: I do. In reverse order, I would say it's important even if someone tells you that you're too old or you should just live with the condition that you have, if you have amblyopia, if you're willing to work at it, don't let the doctor make a value judgment for you. Just present me with the options and let me, as the patient, make an informed choice. Part of that information should be that there isn't any upper age limit to success, if you define success as significant improvement.
Also, amblyopia affects a lot of aspects of life. We know now from research that it's not simply, oh, one eye doesn't see as well as the other eye, but so what, I still have a decent spare tire, so to speak. It impacts many things in development from reading to life skills, in terms of eventually driving, and other things that you might take for granted that are very important in terms of how well you're able to use both eyes together as a team.
Dr. Freeman: Great. Well, thank you. This has been very informative. Thanks for sharing your time with us. Thank you.
Dr. Press: My pleasure. Thanks again for having me.