Myopia is becoming relatively more common in children than ever before. In developing countries, the simple use of glasses by school children can help correct vision but despite this, it is not yet as common place as it should be . Learn how to manage myopia correctly in children through this webinar.
Lecturer: Dr. Leo Seo Wei, Dr Leo Adult & Paediatric Eye Specialist Pte Ltd, Singapore
Panelist: Adedayo Adio FWACS, Consultant Pediatric Ophthalmologist
University of Port Harcourt teaching hospital, Nigeria.
Chairperson, Nigerian Pediatric Ophthalmology and Strabismus Society (NIPOSS)
[Adio] Hello, everyone. So NIPOSS is a society of all pediatric ophthalmologists in Nigeria who are committed to ensuring the overall eye health of the Nigerian child. So you’re all welcome to this educational segment of NIPOSS. We’re transmitting from Nigeria, Port Harcourt, where I live. I’m the Chairperson of the Nigerian Pediatric Ophthalmologists. And I’m very glad you’re here with us this morning.
It is here where we are in Nigeria. So by way of introduction, Africa, which some people may call a country, is the world’s second largest and second most-populous continent after Asia. And it has 1.2 billion people in the 2016 census. It’s a continent, it’s not a country. And that’s where we are in Nigeria. Transmitting from Nigeria at the moment. Nigeria is located in West Africa. It has the 36 states, the capital is Abuja. And we have a largely pediatric population with 186 million population, and 90 million are under the age of 18 years. You can see our work is cut out for us.
So all pediatric ophthalmologists are just very few in number. They’re about 37 in number, which is less than 10% of the number of pediatric ophthalmologists in the whole country. And we’re all spread out in different places, about 21 centers, showing by the black dots in the map of Nigeria you’re looking at.
So why this topic? Myopia is very important because it’s now seems to be a great epidemic of public health importance that will affect at least half of the global population by the year 2050. It’s not yet a problem in terms of numbers in Nigeria, at the moment, because we have less than three. But we know that its complications can cause, 3%, its complications can cause irreversible visual loss. It can also, because we’re in a developing country, where we have poor access to good quality spectacles, and we know that most of the population are regularly, parts of the country are gradually getting organized. This is contributing to the myopia epidemic and may possibly happen in the next few years.
Also a lot more kids are living in the cities than ever before. We have more classwork, heavier work, and all that time spent studying because of the high competitive nature of education, more personal devices in use, and more children are being allowed to play less. Because most people are not, they don’t allow their children to play outside. Particularly in urban cities in the country. Coupled with poor access to eyecare, poor access to quality spectacles. And once they’re damaged, replacement is usually difficult because of the expense.
So we need to begin to look at preventative/modifying strategies. And that is why there’s this collaboration with Cybersight. So that we can have experts from all over the world who have been seeing a lot more of these conditions like the special guest of today. Talking to us about what myopia is all about, how that we manage it and all the recent concepts that we need to understand so that we can prepare for this epidemic that is looming.
Our lady of the day, Dr. Seo Wei Leo is going to be speaking to us, she’s living in Singapore and she’s a senior consultant ophthalmologist. She graduated from the National University of Singapore as far back at 1996, with prizes. And she had a basic specialist training in Singapore National Eye Center and the Tan Tock Seng Hospital, where she also had Advanced Specialist training in Ophthalmology. She has a Fellowship of the Royal College of Surgeons of Edinburgh. And has been inducted as a Fellow of the Academic of Science of Medicine in Singapore in 2004.
As expected, she has won several awards, she has published several papers. We’re together members of the scientific board of the World Society of Pediatric Ophthalmology and Strabismus. And she has special interest in strabismus surgery and other conditions, especially refractive errors and learning disabilities in children. She speaks several languages, but at least we’re happy that she can speak English. (laughs) So she’s going to be speaking to us today. I would like you to welcome Dr. Seo Wei Leo to speak to us about myopia. Thank you very much. I know you will enjoy it.
[Seo Wei] Hello everybody, it’s my pleasure and honor to be speaking across continent to our friends in Africa. I’ve never been to Africa, but I hope to be there someday.
In Singapore, we are the country with one of the highest prevalence of myopia in the world. That’s why I think we have a lot of experience in that. So today I’m going to focus on the interventions to retard myopia progression, what are the types of things that have been tried, what is the pros and cons of each type.
Usually in my clinic setting, the parents will walk in with a child and the parents are usually are very worried about the progression of the myopia. As you know, they know that the higher the myopia, the higher the risk of blindness next time from retinal holes, retina detachment, advanced cataract, and glaucoma. So all these blinding complications are what they’re worried about. It’s not just about the thickness of the glasses. So the typical questions they will ask me is what works for myopia, should I try special eye drops, should I try special glasses, or should I try special lenses?
I would like everybody to look at our WSPOS website, since both Adio and I are the Scientific Bureau of the World Society of Pediatric Ophthalmology and Strabismus. We have our current approaches to myopia control, which is one of the consensus statement that is available on the website. I’ve also published a recent article in 2017 in “Current Opinion” on this topic.
As we know that now it’s an epidemic in urban Asia. A lot of our kids are getting myopic. We are seeing increasingly early onset. So the earlier, the younger they become short sighted, the more they progress and the higher the progression.
In Singapore, as you can see, this green line here, we are really top of the charts together with other urban Asian cities like Hong Kong, Singapore, or Taiwan, and South Korea all are up there. So when we talk about myopia control, I like to remind everybody that there’s actually two ways we have to think about it. Firstly, we have to try to slow the onset, that means not even make it come on. And secondly, once it has come on, we have to try to reduce or slow down the progression.
I would just like to start off with an overview. This is one of the best network meta-analysis study that’s been done. It was published in 2016. Basically, this is a summary of everything and then we’ll go through with the details. When we talk about a network approach, it’s an extension of traditional meta-analysis that allows direct and in-direct comparisons, even when two strategies have not been directly compared. That’s why, with this kind of network analysis, it integrates all the relevant data without losing the strength of randomization in individual randomized-controlled trials. So this is a combination of all your randomized-controlled trials. Where we talk about the 16 interventions, all the different types, different dosages of atropine, different types of glasses, different types of contact lens.
When we talk about myopia research, we think of it in two different ways. One way to talk about the differences is in terms of the refraction change. So in terms of refractive error, a positive mean difference indicates that the first intervention is better. That means the more to this side, the more positive the changes the better. When you think about axial length. So you want to slow down the progression, you want to reduce the axial length elongation. So in terms of axial length, a negative mean difference will indicate that the first intervention is better. Which means that you want something that is more positive here and more negative here to be the best sought out intervention.
When you look at the overall summary, it’s very clear that all the yellow ones are atropine. Atropine drops, in different concentrations, definitely works the best. So I just wanted to summarize with this first before we go into all the other details.
So the other interventions, this one in red, is orthokeratology. You will see that there’s not much data in terms of refraction change. Most of their data is in terms of axial length. And these are other sorts of lower down and other sorts of contact lens and single vision lenses. You’ll find that for contact lenses, there’s really not much different in using it as an intervention.
Before we start with something more intervention, what about lifestyle changes? I think it’s now very well documented that sports hours and outdoor hours are very important to reduce the onset of myopia. Because children who spend more time outdoors are less likely to become myopic. This has definitely been shown in the Orinda Longitudinal Study, where definitely lower amounts of sports and outdoor activity will increase the risk of becoming myopic in those children. Especially those whose parents are more myopic, two myopic parents. It makes sense, right? The more genetic respecters you have, the more likely you are to have myopia.
In the Sydney Myopia Study, as well, they found that higher levels of total time spent outdoors, rather than a specific sport, per se, was associated with less myopia. So that’s why I tell my patients, you should just really, to make it less likely to even have the onset, you should spend more time outdoors. It doesn’t have to be a specific sport, per se, as long as you’re outdoors.
In Singapore, closer to home in Singapore, we have the Singapore Cohort Study of Risk Factors for Myopia. And definitely it shows that total sports was negatively associated with myopia. It’s good to have sports, but not indoor sports. We have to stress outdoor sports. Why is that so? We don’t really know the actual reason, but it’s been really very well established that there’s definite associate with time spent outdoors and myopia in children. So there’s a 2% reduce odds of myopia per additional hour of time spend outdoors per week.
What is the protective effect in outdoor play for to reduce the onset? It is suggested maybe sunlight should be 10,000 lux or more, but we don’t really know the underlying mechanism. It has been put forth that maybe there is a release of retinal transmitters such as dopamine, which will inhibit the eye growth in certain circumstances. However, when you actually look deeper into the data, when you have increased time outdoors it does slow the onset of myopia, but it does not seem to affect the progression as much. So this is an interesting thing because by right, both onset and progression of myopia depend on axial elongation. So it’s not really clear how you can differentiate it and regulate it like that. Which means that really outdoor play you increase it, it protects you from becoming myopic more than it protects you from progressing. But there is still some effect. So it is really important to get our kids outdoor before they become myopic.
In Singapore, our health ministry has been very active promoting all these so that we have all the campaigns. We tell them, “Keep myopia at bay, go outdoors and play.” This is part of our Health Promotion Board campaign.
Again, now I will go through the other interventions that have been done. So that to give everybody evidence that based on a different intervention. So I’m going to be talking a little bit about eye drops and other optical treatment.
I think in Singapore, we use a lot of atropine. Atropine eye drops is actually, atropine is a non-selective muscarinic antagonist. It’s been used, actually, for myopia for a long time, as early since the 19th century. In Asia, I think the trend of using that for myopia started in the 1990s. The early studies shows that there was definite clinical effect on reducing the progression of myopia, even though we didn’t really know what was the mechanism of action. But we did know that its effect on myopia was definitely non accommodative. This is because when you use atropine eye drops, in chicks with striated ciliary muscles that were innervated by nicotinic receptors, rather than muscarinic receptors, the eye drop was still effective. Which means it is not on its accommodative action that you are reducing the myopia.
So how does it actually work in myopia? There’s two theories. It is either using the neurochemical cascade, which begins with M1 or M4 receptors at the retina, possibly, the amacrine cell level. Or the other possibility is atropine acts directly on the sclera by inhibiting glycosaminoglycan synthesis via, again, a non-muscarinic mechanism.
So the most definite studies were done in Singapore. ATOM 1, which is a few years ago, it was the first randomized, double-masked, placebo-controlled trial involving 400 Singapore children of primary school age. Where they received 1% atropine every night in one eye, over two years. And there was a significant reduction in myopia progression by 77%. The group that received atropine 1% progressed by .28 diopters in two years. For as the group that did not receive atropine, progressed by 1.2 diopters. The atropine group’s axial length was also unchanged, whereas the control group would have lengthening of the axial length. And we found that the kids could tolerate atropine 1% very well. Multifocal ERG studies showed that there was little effect on the retina function.
However, with 1% there were side effects. As we know, 1% dilates the pupil, so it makes the child scared of sunlight and there’s lots of photophobia. Because it is also a cycloplegic, there is decreased near vision. And as a result, the child will need photochromatic progressive additional lenses. Of course, systemically, there can be some patients who complain of dry eye, mouth, throat, and flushed skin. A follow up study of ATOM 1 participants actually revealed that the effect of atropine on cyclopegia was fully reversible after they stopped the eye drops. However, while they’re still on eye drops they will definitely need photochromatic progressive additional lenses.
These are some pictures of our patients who are on atropine 1%. You’ll find the kids, they use the progressive very well, they’re not like adults who take a long time to adjust. So naturally when you show a child some atropine, this is in the days of 1%, when you show them something near, they will naturally tilt up their head to use the bottom segment to look near. And when you ask them to look at the distance they will automatically use the distance and they use it really well.
In Singapore, it’s still a very sunny place. This is a picture of my son, actually, when he was young he was on atropine 1%. So despite the photochromatic lenses, he would still find these very glaring when he went outside. So advise them to wear caps or hats as well.
With 1% being effective, but with side effects, we explored lower concentrations of atropine. So we tried out ATOM 2 study where they looked at lower dose. 0.5%, 0.1% and 0.01%. After two years, it was found that there was effect in lowering myopia progression by all these lower dose. Obviously, it’s still dose-dependent. The higher doses, the more concentrated atropine worked better than the lower concentration. With call responding differences in the axial length.
So if you combine the results, you’ll find that the lower dosage is less effective, because it’s dose-dependent. Higher dosage atropine definitely it’s more effective. Roughly, 1% would slow myopia by about 80%. .5% slows it by 75%, .1% slows it by 70%, and 0.01% slows it by 60%. However, once you stop the atropine, there can be a bit of rebound. And the rebound is high again, dose dependent. The deep rebound is higher with the higher doses and less with the lower doses.
One year after stopping atropine, these were the rebound. Rebound was greater in the higher doses with corresponding changes in the axial length growth. So what does that mean? This means that overall, if you look at three years of atropine, two years on atropine and one year off atropine, the placebo group actually progressed, obviously, the most. And the lowest concentration, 0.01%, progressed the least because there was less rebound. This means that the lower dose is actually very, very safe and there is negligible effect on accommodation and pupil size and it doesn’t affect your near reading so you don’t need progressive additional lenses. There was minimal local side effects like allergic conjunctivitis and dermatitis. And still it is quite efficacious in controlling myopia progression.
In our country, we are quite fortunate, we have the different formulations available. We have atropine 0.01%, this is atropine .125% that comes in single vials, these are single vials. The preservative-free single vial. We also have the preserved bottle option. We’ve been quite fortunate we have that.
I do want to address the other issue, which is with rebound. Clinically, of course, during the trials they stopped at two years and then they’ll be people with a rebound. So clinically, what we do is we use it actually longer than two years. We monitor the axial length and only when the axial length stops elongating, then I stop the atropine. That is the only way you will get rid of the rebound, there will be no rebound when you stop because the axial length has stopped. But the trials, because they were limited to two years, that is why I think you get a lot of rebound.
The Hong Kong studies have also proven the effect on myopia progression in low dose. The Hong Kong people used 0.05%, 0.025 and 0.01% and they found that, of course, 0.05% was better than 0.01%. Theirs was a more recent study and the main difference with theirs had the control group in the same trial. That means they used 0.05, 0.025, and 0.01, and placebo in control group. Whereas ours, our control group was a historical control group from ATOM 1. I think that’s the difference. To share with you the Hong Kong study, the LAMP studies that also show that definitely the low dose was effective.
What about are there any risk factors, that means, are there people who do not respond so well to that? In our study in Singapore, we show there was about 12.1% of people who still progressed by more than .5 diopters despite being on atropine. And we found that these are people who tend to be younger and they had higher myopic spherical equivalent and they also had myopia parents. So now I always tell my patients that not everybody’s a responder. There are people who don’t respond and these tend to be the younger ones with the higher degree and whose parents are also myopic.
I will say that in my practice, definitely I tell them that atropine eye drops is an evidence-based clinical practice. I use it when there’s a rapidly progressive high myopia. Especially if there’s a strong family history of high myopia. I usually start out with the lowest done, 0.01% nightly. They do not need progressive additional lenses. I do warn them there can be 10% non-responders as shown in our previous Singapore study. But in my own patient population it’s actually much less than 10%. I will start with 0.01%, the lowest dose, if they don’t respond then I would increase to different concentration. 0.1% or even 1%.
The important thing to note is that to avoid the rebound, I never stop abruptly, I will be monitoring the axial length. I think this trend of prescribing atropine, it’s not only in Singapore, even in Taiwan they have shown that the prescription has increased greatly since from years 2000 to 2007. And they have also been shifting from prescribing high concentration to low concentration atropine. They found that atropine was also more frequently prescribed to nine to twelve-year-olds and to children from families with highest socioeconomic status.
For the American Academy of Ophthalmology, they have also acknowledged that Level I evidence supports the use of atropine to prevent myopic progression. Although there are reports of rebound, this seems to be minimized by using the low dose, especially 0.01%.
So what about atropine to prevent the onset? It means your child is not even myopic. Do you try to use atropine? I personally don’t really do that. But there has been a retrospective study in Taiwan that gave kids 0.025 atropine over one year period, even though they did not have myopia. And they found that the myopia shift was significantly lower. So that’s something that can be discussed with parents.
Many years ago I was also involved with the Asian Pirenzepine Trial. This was a gel, which is a selective antimuscarinic agent. It was used to slow down myopic progression by using the gel twice a day. Actually, the effect was pretty okay. There was 40% reduction after 12 months. However, this gel is no longer commercially available. But I did use it when it was part of the trial.
Now we talk about optical measures. There was a lot of excitement about optical measures because from the chick studies, they found that negative lenses, from animal studies, they found that negative lenses cause the eye to grow and positive lenses reduce growth. Which means that when there is a hyperopic defocus, where the conjugate point of the object of regard is behind the retina, it will stimulate the eye growth to move the retina toward the conjugate point. Whereas, if you have a myopic defocus, whereas putting a positive lens, it would stop the eyeball from growing, especially in chick’s eyes.
Because of that, there was a lot of excitement. So they thought that with positive lens should we use bifocal lens? Because it was postulated that maybe bifocals or multifocals may reduce accommodative demand and retina defocus. However, a lot of randomized controlled trials showed that it is actually not effective. So this is not an effective intervention.
Progressive additional lenses with a plus two add, slowed the progression of myopia by a small statistical amount. But this, just like .2 diopters after three years. So this did not warrant any changes in clinical practice, as shown in COMET one and two trials.
What about other special types of glasses or in Singapore we have different brands who comes up with different sort of glasses? There has been one of the brands used is bifocal and prismatic bifocal spectacles on myopia progression. Where they gave kids bifocals or bifocals with three prism diopter base in prism. There were some, a lot of criticism of the results because the randomization was not standard and the investigator was not masked.
Again, a few years ago there was a lot of excitement with all these peripheral defocus in animal work because they find that peripheral vision signals can direct refractive development. So it was thought that peripheral hyperopia could stimulate axial elongation. That is why you could maybe try to see whether this will work to reduce myopia progression. However, when they did more analysis, like in the CLEER study, relative peripheral hyperopia appears to exert little consistent influence on the risk of onset of myopia or the rate of progression. So we don’t really know whether this is a causative role. It’s not been confirmed. So it could be it’s a result of your myopia that is why the shape of the eyeball is like that, rather than it’s because of this that causes myopia.
So because of all these peripheral defocus interest, it was suggested that because your traditional correcting lens, the inner shell is like that, you’ll end up with a periphery defocus. So it was thought that if you had different types of lenses that will bring the peripheral image forward so that you get clear vision centrally and peripherally, whether it was possible to correct the myopia progression. So there was a lot of interest in that. And because of that, there were different lenses and spectacles designs to try to do that, however, I think the results have not been so good. There was no statistically significant difference in using these special lenses. If you look at the different types of, I will say, these special spectacles, I think the effect is not great.
What about contact lens, per se? The normal contact lens, as again, is close to midline, it doesn’t really favor treatment. But there is a special group of contact lenses that we need to look at. So I think the other most popular group is the corneal refractive therapy, what we call orthokeratology. And there are different types of special lenses. These special contact lenses were, again, designed to try to reduce the relative peripheral hyperopia at the site. And so they have these special contact lenses that the refractive power of the lens increase progressively in relative positive power to reach a relative positive power of plus one and plus two. And they found there was some effect to slow down myopia progression. They also tried these soft contact lenses, what we call defocus soft contact lenses. Again, there was some effect, 25%. So all these effect may be a little bit on prior myopia progression, but not as good as our 50% or more that we get with atropine.
Again, they have the different technologies tried and most recently, CooperVision, they have set up shop in Singapore. I’m not sure whether they are in Africa. It’s called MiSight lenses. It’s a dual-focus myopia controlled daily lenses. Again, in their clinical trial where they had, actually I will say it was quite a small trial. 53 test subject, 56 subjects, they found that there was some difference between in the myopia progression. It did slow down myopia progression when you use their dual-focus contact lens compared to the normal contact lenses.
I would say that among other different contact lens, the most effective, I would say, is still orthokeratology. Orthokeratology is also known as OK lens, corneal reshaping lens. This is a special contact lens where the child wears it overnight. Uses reverse-geometry lenses so that it temporarily reduces the myopia by causing central epithelial thinning, mid peripheral epithelial and stromal thickening. And in the day the child does not need any aids at all. The effect is temporary, so every night you have to wear these special reverse-geometry lenses.
So the optics behind this is that there’s a central optic zone that is fitted flat relative to central cornea curvature, surrounded by one or more steeper secondary or reverse-curves. So peripheral to the reverse-curve zone, that are flatter curve fitted in corneal alignment and sometimes an extra peripheral edge to provide edge lift. So this is the optics behind them.
There have been quite a lot of trials done to try and see whether they reduce myopia progression. So when you look at that data, I would say that a lot of the trials were not so randomized-controlled trial. Most of their trials, there were three prospective randomized trials, seven non-randomized, and three retrospective case series. So in terms of Level I evidence I would say there’s only one trial that is Level I evidence. And a lot of times because what happens is, think of it like molding the cornea. So in the day when you don’t wear anything, it’s temporary, you don’t have to wear anything. But your refractive error, you don’t really know the true refractive error because every night you’re binding that. So in a lot of the trials, they only studied the axial length rather than the true refractive error. They found that there was about 50% after two years that was reduced axial length elongation. They found that younger aged group and people with larger than average pupil size, may respond better with Ortho-K. But as in all our other interventions, they can always be rebound after this continuation.
I would say that generally, for Ortho-K, the effect’s less than 50, it’s about 40%. But as in other interventions, the problem is the efficacy. In the fourth and fifth year there was no significant difference between control group and OK group. How does OK lens work to reduce myopia progression? We don’t know. Maybe it could be a combination of the, like we said, the peripheral refraction. Remember now we know that peripheral refraction it’s important somehow. Maybe they convert relative peripheral hyperopia to relative peripheral myopia to slow down progression? And we don’t exactly know how it looks for myopia progression.
But I would like to say that that’s still advantageous. I do have some patients that I ask them to wear Ortho-K. Because it eliminates the need for daytime contact lens or spectacles. So I have patients who are water polo players, synchronized swimming. Water polo players, their coach needs them to open their eyes underwater without, so they can’t be wearing day contact lenses or glasses or goggles. So Ortho-K works for them, more for the optical part of this. But the disadvantage, a lot of these trials, there were a lot of flaws with the choice of control. There were very small numbers and high drop-out rate. And there’s no good control, long term study demonstrating the sustained effect. Because most of the results are very short term. There’s no wash out data, and they can increase the higher-order aberrations of the cornea and decrease contrast sensitivity.
For me, I think for my patients, the main reason they don’t like it is there is reduced vision acuity as the day progresses. Because in the morning, when you take off the contact, their Ortho-K, everything is clear. But as the day progresses, there’s a natural rebound of the cornea back to its original cornea contour. So there’s a slow myopic shift towards the end of the day. So some of my patients, they found that they have to start to wear glasses by the evening if they need to see far. So of course there’s a lot of issues of cost, discomfort, and problems with removal.
But the main issue I have with them is infective keratitis. I think in the literature now, there’s more than 160 cases being reported. The most common organisms we isolated, that’s Pseudomonas and Acanthamoeba. These are the published data, I’m sure there’s a lot more cases that’s not published. The rate now is about 7.7 cases per 10,000 patients. In Singapore what happens is the Ortho-K is prescribed by optometrists, so we don’t see the patients until they get a terrible infection. So I’m going to show these are all pictures of patients that I treated for infective keratitis. So I tell my patients, yes, you can say it’s 7.7 per 10,000 doesn’t look high, but that one case life is really bad. Because they tend to get very bad central infective keratitis. So these are patients with whopping infective keratitis.
And this patient, an Ortho-K, ironically is actually an optometrist herself. And she came to see me with infective keratitis. And this is another of my patient. So they were fitted by the optometrist elsewhere, they only came when they had infective keratitis. This girl, very bad Acanthamoeba, infective keratitis by the time she presented to me. Eventually we needed to do a cornea transplant for her. And she literally had to take one year off school with all these in/out, with all the infections and the surgery.
This is my worst case of infective keratitis secondary to orthokeratology. I was literally shocked when I saw this patient. Really, I feel that the risk of infection really has to be emphasized to patients because the risk is much higher than your normal conventional contact lenses. Of course the other effect on the cornea, there’s a bit of cornea staining, it can be sporadic diffuse punctate staining. Sometimes there’s patchy central staining, sometimes there’s peripheral rings. If it’s more obvious, obviously if the myopia is higher or some patients still report lens binding and reduce tear secretion and tear film stability.
Interesting thing to note is after many years of Ortho-K, these patients always have this iron deposition. These are subepithelial, very common. It coincides with the area of greatest corneal curvature change. You don’t require any treatment, but you can see after they’ve been Ortho-K for some time.
What about the corneal changes, per se? There is a little bit of central corneal thinning with Ortho-K, but the magnitude is very, very small. I would not think that it would cause any ectasia. There is no impact on the density or morphological features of endothelial cell. There has been some decrease in corneal hysteresis and corneal resistance within the first week of treatment, but they do return to normal baseline after some time.
What is a new perspective now on myopia control with Ortho-K? Again, we don’t know whether it really works by causing myopia defocus on the peripheral retina. And that could be a critical threshold of retinal area receiving myopic defocus that is needed before the Ortho-K’s effective. And we don’t know about the impact of duration of exposure. There’s still a lot of unknowns.
Then the other question I get asked by my patients is, “Do we do combination?” That means, do we do atropine low-dose with Ortho-K? I would say that in my patient population, yes. I have a few anxious parents who have actually tried this combination. But these are just a few. In some proper studies, I think there’s been two publications so far. Again, they found that in this China study, they found that in the younger patients, especially when they were on Ortho-K and there was still quite a lot of significant axial length elongation, they would add atropine the second year, and found that there was really a great reduction in myopia progression and axial length elongation, once they do additive effect. That means they started with Ortho-K first, then the add on of atropine 0.01% on top of that. So that could be something to think about, a combination therapy.
I would end off with a few other optical measures. The other common questions that I get asked is, “Do we purposely undercorrect the child?” Because in the past, it was thought that if there was a myopia defocus, maybe we could have a growth response to what’s hyperopia. However, the trials have actually shown that the undercorrected group, if you don’t give them the myopia correction that they need, the undercorrected group can actually have a significantly higher rate of myopia progression. I think the consensus is undercorrection did not affect myopia control and could even worsen the myopia progression. And recent, non-interventional large-scale prospective Chinese cohort definitely proved the lack of effect with undercorrection. So I do not purposely undercorrect my patients. I just give them whatever they need.
What about part-time lens wear? Again, some patients ask, “Do I only wear it sometimes?” The data on 43 subjects shows that there was no effect, that means you don’t need to try purposely only wear it part-time.
So to conclude off, I would think that atropine eye drops are still the most effective so far. Ortho-K that is emerging evidence. The advantage of Ortho-K is that it eliminates the need for daytime contact lens or glasses, however, you got to weigh that with the risk of very severe infective keratitis.
Again, this is our consensus statement. What I usually tell patients to do is if you don’t want myopia to even start, try to increase outdoor play because that will reduce its onset. And to reduce progression I will say atropine is the most effective. For Ortho-K, I would consider it if the child needs to eliminate the need for daytime contact lens or glasses because of their special sports or anything like that. And there is also emerging evidence for retardation of myopia control.
Thank you, very much, for your attention.
[Adio] Great, thank you very much. I would like to find out, Dr. Leo, for those patients here. For those patients who have been given atropine, what is the age? What age group do you usually give, what age do you start the atropine and what age do you stop giving the atropine? We don’t have ready-made atropine here. That’s a second question. We don’t have ready-made atropine here, so we have to mix it with Tears Naturale to 0.01% concentration. So those two questions.
[Seo Wei] To answer all that and also because the questions that have come in, how long can atropine be used and what age does the eyeball stop growing? The trial for atropine was started, the ATOM trials, they were for primary school kids from 6 years onwards. There was when they used 1%. And actually, atropine 1% in the main trials they used it even for up to five years. So because they did the full op trial and all that. However, because now we have low dose, can you imagine if you used 1%? Technically your 0.01% you can use a hundred time more. To me, with a low dose, I am not worried. I have started for kids as young as three to four years old, especially if they’re very strong family history and their myopia is progressing quite rapidly. I don’t start a child that I’m not sure of, I usually monitor them. I see the, and I see them again, so I know progression before I start.
And how long can it be used? I think with the 0.01%, it can be used for a very long time. Because virtually, there’s no effect on the pupils. And what I do is I monitor the eyeball length, the axial length. When the eyeball stops growing, then I will stop the atropine. I actually monitor the eyeball length.
What is the average age? Some patients I stop at 12. My own son, his axial length stops at 12. There are some kids that stopped later, 13, 14, 15. I think by 15 a lot of them would be stable. However, having said that, I have some patient that I stop, they were okay for some time, and then they, in university or in high school, they read a lot and then it starts again. I have some patients who are a bit older, late teens, that are still using atropine. It depends.
[Adio] Okay, someone else said is there any study comparing the use of Ortho-K with atropine and the effect on spectacles?
[Seo Wei] Yes, there is. I think that they did have small trials of that compare directly, Ortho-K and atropine, there has been. I think that’s why I said that, in those small trials there is some effect on Ortho-K, but I think atropine is still more useful. So I think the trial was trying to show that it’s almost the effect of OK lens with the atropine.
[Adio] What do you suggest for parents who don’t allow their children to play outside? What else, talk about indoor sports, that is not as effective, it’s best to be outdoor sports. What do you suggest for those who are living in high rise building who don’t really play?
[Seo Wei] I would think that they’d still try their best and try to look-
[Adio] And how many hours do you suggest is best?
[Seo Wei] I tell them 14 hours per week, actually. 14 hours per week of outdoors is what we recommend. About 14 hours a week.
[Adio] 14, 1-4, okay.
[Seo Wei] 1-4 a week. I mean if they can achieve that, that would be good. And there was a trial, a small study that showed that if you don’t allow them to go outdoor, if you actually in a glass house, because they feel that the light is important in a clean house, in a glass house. Reading is still better, more effective than reading inside, indoors. So you need all the sunlight.
[Adio] Okay, because we have a lot of bookworms (laughs) in Nigeria. Those who like to read a lot.
[Seo Wei] That means they sit outdoors to read. They sit outside.
[ Adio] Okay, okay, that’s something else to do, okay. All right. So someone was asking, do you advise taking off glasses for near work? And to use of tablets and phones and stuff?
[Seo Wei] If you take off the glasses for near work, it will be equivalent to your bifocal trials. Because when you take off to read, you’re leaving them myopic for near. So it’s similarly to doing the bifocal. So I don’t do that because the trials have shown that there’s no effect on myopia progression if they take of to read.
My worry is more logistic because patients who take off to read then, take off, put on, they will end up losing the glasses, a lot of things, it’s more logistics. Of course, for tablets, phones, and other near work, I would like to stress that for near work that definite evidence it’s very conflicting. There are some trials that show that it doesn’t matter, there’s some trials that shows that it works. My personal view that on near work is that it’s very hard to quantify near work. But I feel that there is definite some association with myopia progression, not specifically the blue light, per se, I think it’s the intensity of near work. So I actually do limit them to try to reduce as much as possible, iPhone, tablets, all these kind of near work. School, we kind of expect them not to do, but the rest of the time I try to tell them not to do unnecessary near work on tablets and phones and computers.
[Adio] There’s a question there on fraternal twins, how effective is this atropine for hereditary myopia? For example in fraternal twins?
[Seo Wei] We have what we call the congenital myopia. There has been no trials done, but I have had a few patients on this and it seems to. Because these kids, with the hereditary, they are the congenital type, they present very early and their myopia is really high. And I have a handful of them and it seems to work. But these are not big trials, but it seems to work.
[Adio] I have a patient who has high myopia in my one eye, minus 10, and the other one has a normal refraction, plus one. So what do you suggest for such a trend?
[Seo Wei] First to get them on the proper glasses. When it’s a child, even though it’s minus 10 and plain, they will be able to adapt. They don’t need contact lenses. Then you monitor the progression. If the minus 10 is progressing, you can put atropine, actually. But of course, you have treat the amblyopia and all that first if there’s amblyopia.
[Adio] Yes, there definitely was, very dense amblyopia.
[Seo Wei] Yeah, so we would treat the amblyopia first, so don’t use atropine when they’re still amblyopic. Unless you’re using atropine as amblyopic treatment for the other eye.
[Adio] Okay, all right. There are no more questions.
[Seo Wei] I think there is one more question. For kids above age four, what is the smallest power of myopia you would correct?
Actually, it’s a case-by-case. I always say, you know this, again, this prescription or glasses, it’s not just a science, it’s also it really depends on the situation. If the patent has exotropia, even though it’s a very small amount of myopia, I would correct. But if the patient does not have any exotropia, if it’s less than one diopter, I would tend to leave alone, if it’s .5 or .7. Only if the child has, the eyes are straight. A lot of these, they tend to have a little bit of exophoria, or intermittent exotropia, then definitely we have to correct the myopia.
[Adio] Okay, what I tend to do is, I like to see them at least twice.
[Seo Wei] Yeah, I need to get the accurate power as well and to get-
[Adio] Power, if it is different within a year, by 0.5 or six months, then I start on the atropine. Now would you like to start atropine on someone whose eyes have stopped growing? Like a 12-year-old? Or 13, if you’re seeing them for the first time?
[Seo Wei] I don’t usually start someone that I’m seeing on the first time with atropine because I think we need to discuss and I need to see that there’s some progression. Because if they’ve really stopped progressing then you really don’t need it.
[Adio] No, what I mean is, you’ve seen them, you’ve seen that they are progressing. In terms of whether you’re seen them twice, actually, so three times and it’s progressing. But it’s a little bit old, right? The eyes should have stopped growing by that point.
[Seo Wei] No, like I said just now, sometimes they still grow even after 12. So you can still use, because I have some that still grow. Yeah.
[Adio] All right, so someone has raised their hand here. (laughs) Okay. I think he’s just typed a question. Seo Wei, a new type of question.
[Seo Wei] When and how do you commence treatment after rebound of myopia? Okay it means you stop and it came back and then you have to restart again the atropine. You just have to start. So I usually monitor.
Is there any contraindication for children with glaucoma in the atropine therapy? To me, it’s unless you’re talking about narrow angles, there is no contraindication. That means your patient has, I suppose, congenital glaucoma and later on has progressive myopia. I don’t think it’s contraindicated. But I do usually look at the, I do check the eye pressures for kids and I make sure that they’re not having any narrow angle.
What is the maximum age limit for kids beyond which you cannot use atropine? It’s not the age, per se, it’s really it’s whether the axial length is still lengthening. I have used, even when they’re more than 12, if I still think that they’re progressing and the axial length is increasing.
[Adio] Nice discussion. (laughs) I think we have come to the end of this session. It’s been a very stimulating time. A lot of questions are coming on time to start, time to stop, so it’s really a question of the axial length. So as you’re monitoring this patient, keep checking the axial length and that is when you stop. And of course, before you start, you really should actually have seen the measurements twice. Check that their progression is at least not less than 0.5 or not 0.5 different from where you saw them last, diopter. And then now it’s time to start 0.01% atropine, which is the best with the most minimal side effects.
And I would like to confound, when you stop, that’s once a day atropine, you want to prevent rebound. You’d like to give twice a week, right? Kind of taper off, Seo Wei?
[Seo Wei] Okay, so for me, if they are on 0.01%, because it’s so mild, I don’t taper. But if they’re on the high dosage, then we do tapering.
[Adio] Oh, okay.
[Seo Wei] So if they’re on the high dose, then we taper. But once it’s on the low dose, the 0.01, I find there’s really no need to taper anymore. Yeah, you can actually stop because it’s so low dose. And once everything is stable.
And the other thing, I’m not sure how it is in Africa, but for the Singapore kids, when you tell them to use every night, they don’t really use it every night. So it’s kind of, especially when they are quite. Usually I tend to say more than. If you tell them, “Oh, just use twice a week,” they’ll end up not using, I think. It’s like that. Is it the same in Africa? (laughs)
[Adio] Kids are the same everywhere, that’s exactly what they do here also. They just, sometimes the bottle even finishes a week before they even come back for a refill. (laughs) Sometimes that’s what happens.
Okay, thank you very much, Seo Wei.
[Seo Wei] Thank you.
[Adio] We really enjoyed the time with us.