Insights into Childhood Myopia

Denise Balch: 0:00

Welcome to the next in the Canadian Association of Optometrists Podcast Series. My name is Denise Balch and today we will be speaking with Dr. Deborah Jones about myopia. Dr. Jones is a clinical professor at the School of Optometry and Vision Science, and a Clinical Scientist at the Center for Ocular Research and Education at the University of Waterloo. Welcome to our podcast today.

Doctor Deborah Jones: 0:24

Thanks very much.

Denise Balch: 0:26

I'm going to, as I usually do in these podcasts, I've got a list of questions here, but I'd like to start with a definition of myopia. So perhaps you can explain to our listeners what myopia actually is, and maybe some more details in terms of the typical age of onset and how it actually affects the vision of those who are diagnosed.

Doctor Deborah Jones: 0:49

Yeah, absolutely. I mean, I think it's always important to make sure we understand what we're talking about. So myopia is also called near-sightedness, it's sometimes called short-sightedness. And what it means is, without a vision correction, you can see clearly up close and you can't see in the distance. So that's the kind of plain and simple definition. In terms of age of onset, I mean, certainly when I first graduated way back - hard to imagine now - way back in the 1980s, we typically saw the age of onset around 11 or 12, and that's when I first started wearing a vision correction. Now we're seeing it much earlier, so we're seeing our children at six and seven, and eight, and even younger than that, coming into their optometrist with complaints of poor vision, and finding out that they too have myopia at this early age. So we are seeing quite a big shift in the age of onset.

Denise Balch: 1:45

And if we're seeing that shift, how big of a problem is myopia and specifically childhood myopia?

Doctor Deborah Jones: 1:53

And that's really the important thing that we're worried about now, is that with myopia comes a whole myriad of potential consequences, particularly if your prescription is high, and those consequences can lead to serious vision impairment later in life. So just a few examples: glaucoma, retinal detachment, myopic maculopathy, which is a term basically for retinal damage at the back of the eye to the central part of your vision. And all of those things, and there are others, can cause vision impairment where even with the best pair of spectacles, you still don't see well. And we know that the risk of vision impairment is higher, the higher the prescription. So if your number is bigger than your risk is also bigger. So, for example, if you have a prescription of minus six, then you're 40 times more likely to have macular problems later in life than if your prescription is perhaps minus one. And when we see children who develop myopia at an early age, we know that it follows a typical growth pattern as the child grows and typically continues to change up until at least the age of 15, or 16. And, in fact, about 50% of young myopic children continue to progress beyond the age of 16. So it comes down to almost a basic mathematical equation. If you start at six and you progress for 10 years, then your prescription is going to be higher than if you start at 11 and progress for five years, and you can imagine, you know, you could expect a child who starts at the age of five or six to have double the prescription that they might have done if they started at 11 or 12. And that therefore increases their risk for vision impairment later on. One of the other things, which kind of resonates with parents, I think more so is, the higher your prescription, the less likely you are to perhaps have successful laser vision correction later on. So if you've got a very high prescription, you may actually not be eligible for laser vision correction, or the outcomes may not be as good as if you have a low prescription. Also, without your correction on if you have a low prescription, it's much easier to navigate. You know, if you're in the swimming pool without your glasses on and your prescription is minus two, it's way easier to navigate than if you're minus eight. So there's lots of reasons why we worry about early onset and high prescriptions.

Denise Balch: 4:29

Yeah, no, absolutely. And you know, we've all seen the the small children that have glasses and just keeping them on their head is a challenge, and you know, I don't know what it's like now for kids in school, but nobody wanted to be the kid that was wearing glasses. I know when you get older you get the cool frames and, you know, it's a cool thing to do sometimes, but there certainly can be some social stigma when you're a child and you're you're wearing glasses. So is this problem getting worse? Like, how many people are we talking, or how many children are we talking about that are diagnosed with myopia? And I guess the other question is, how many do we think are undiagnosed?

Doctor Deborah Jones: 5:11

Well, that's a great question. So it has been termed a worldwide epidemic. And certainly the the World Council of Optometry really has taken this on and tried to make sure that there's a global awareness of how serious this problem is. So there's been a prediction, and it's very well quoted, that by 2050, 50% of the world's population will have myopia, and of that 50%, 10% of the world's population will have high myopia, and that's a prescription over minus six. So globally, a massive problem. And you may think, well, okay, whatever, you know, that's somewhere else., it doesn't apply to us here, but we did some work and looked at the prevalence of myopia, just actually locally in our Kitchener Waterloo region a couple of years ago, and we found that 30% of 11 to 13 year olds had myopia. And what was interesting was a third of those had no idea. So we were the first ones to pick it up when we were doing this project within schools looking at children's vision and measuring that prescription. So it's a massive problem for want of a better word. I mean, I would hate to say that anybody has myopia is a problem. I mean, it's a natural thing. But it's that high myopia we worry about. So yeah, worldwide, it's becoming an issue, and certainly within Canada, we are seeing that increase. And even just anecdotally, I'm seeing a lot more patients, and I'm seeing them in a lot younger age when I myself are in clinic seeing patients.

Denise Balch: 6:54

So the rates of myopia are on the rise, then.

Doctor Deborah Jones: 6:57

Correct? Yes, absolutely. They are on the rise.

Denise Balch: 7:01

Now, we often hear about screen time, and there's a lot of misinformation, I'm sure, out there. So is there anything that makes someone more at risk for developing myopia, and maybe what can parents do?

Doctor Deborah Jones: 7:19

Yep, there's some really good evidence that screen time, or extended viewing at near distances, can certainly lead to the onset of myopia. And if you imagine, you know, if we talk about evolution, if you think the visual system is spending a lot of time focused at near, you can imagine that there will be a natural adaptation to be in focus at that nearer distance and start to ignore the far away distance that just isn't being used as much. And we do have some good evidence from many countries in the world. I was just at a conference recently, and there was a study that came out of Ireland, and they very clearly demonstrated an increase in myopia with children – young children –who spent more than four hours a day on screens. Now, the CAO came out with some guidelines a few years ago on screen time, and while that wasn't just related to vision itself, it certainly is a good guideline to follow, and basically, toddlers – no screen time at all. So zero to two, there's absolutely no reason why a child at that age ever needs to be on a digital device. And when we talk about screens, we're really talking about the cell phone, the tablet, the close working distance TV – still a screen, but it's not quite being used in the same way. And then your two to five year olds, really, again, is there any reason for them to actually be on screens, but certainly, no more than about an hour to two a day. And then over five, it comes down to creating a family plan, and really customizing what works for you as a family. what that child needs, perhaps there's some educational content, you know, schools are now doing a lot of schooling – high schools often give out something like a Chromebook to their students, and that's what they do their homework on, and that's what they use in the classroom. So it's not that we have to avoid screens, and in some cases, we just can't, if that's what homework is being done on, or if mom needs to go and put the laundry in, or dad needs to go and back the car out of the garage, you know, maybe you do give that tablet to the child for that five minutes or 10 minutes. You know, we've all had moments where you need to make sure your child is safe and occupied. But it shouldn't be the first thing we do, it shouldn't be that surrogate babysitter, and certainly seeing children in strollers with iPads hooked to the stroller so that they can be entertained while you're walking down the street. Really, that's a big no-go.

Denise Balch: 9:56

Yeah, I'm seeing in my mind's eye that when I drive by cars, and they have small children, and both children have a screen attached to the back of the driver and passenger's front seats, and they're watching movies, and I was like, whatever happened to the games that we used to play with our parents, which I guess gets us to the next point, and that is, you've talked about screen time. And thank you for giving us some insights into that. But what about outside time? Because seems to me that our kids aren't spending as much time outside because they're inside. Is that true?

Doctor Deborah Jones: 10:36

That is a great point. And yes, it is largely true. And one of the things that we have some really, really solid evidence on is that spending time outside can delay the onset of myopia. So if a child is at risk of myopia, perhaps they have two myopic parents, there's nothing you can do about the gene pool. That's where they came from. But what we can hope to do is delay onset and spending time outside has been shown to delay onset. And it's for two reasons: one is if you're outside, unless you're sitting under a tree with an iPad in your hand, you're probably not on a screen. The other thing is there is some benefit of natural daylight, there's actually a mechanism that happens when you're in daylight, there's a reaction in the retina that inhibits retinal growth. So, coming back to the definition of myopia, I talked about vision, but the reason the vision is blurred in the distance is because the eye elongates, it gets physically longer. So from the front to the back, it gets physically longer, and that's where that retinal stretching happens, which leads to the retinal degeneration. So if you imagine blowing up a balloon, the more you blow it up, and the more that rubber stretches, the thinner it becomes, and the more likely it is to burst, or pulling saran wrap over a bowl - if you've got that really big bowl, and you're pulling that piece that's not quite big enough, then it stretches and potentially tears. So there's a mechanism that sunlight creates, that actually slows down that elongation, or stops the messaging to elongate. So if we can delay the onset, circling back to that mathematical equation as if you start at six and finish at 16, you've got 10 years of eye growth, if you start at eight or nine or 10, because you've spent lots of time outside and we delayed the onset, then your risks are less. So there's a direct correlation, and yes, you're right, if you're outside playing, hopefully you don't have a digital device in your hand that you're playing a game on.

Denise Balch: 12:47

Yeah, no, absolutely. Oh, really excellent information. Thank you. And so you mentioned, just to go back to one of your earlier points, that when you did the local study, you found that I think it was around one third of the children that you examined, did not have a diagnosis already of myopia - the ones who are myopic, one third, were not diagnosed. So if a child is diagnosed relatively early on, say their parent is taking them on a regular basis for eye exams, and they are prescribed a corrective lens, is that going to reduce their risk or other eye diseases or slow down the development of myopia or is it just a fait accompli, it's a foregone conclusion?

Doctor Deborah Jones: 13:38

That's a great question because it depends what they are prescribed. So the first thing

is: 13:43

the take home message has to be that children have to get their eyes examined. So that's always a take home message. And then when we discover a child has myopia, we're hopefully discovering it with a low prescription, because either they're coming in for a routine eye exam every year, or perhaps the child has started to indicate that they're not seeing very clearly. And then at that point, we can start start talking about the options of myopia control. So myopia control is a method to slow down progression of myopia. It can't reverse it, and it can't stop it necessarily in its tracks. But I often say to patients, you know, your child is on the myopic train. Let's see if we can put the brakes on and slow that train down. We don't want it to be a fast express that's just racing along. We want to try and slow that down. There are three basic methods, so contact lenses is one, spectacle lenses – a particular design of spectacle lens – and then there are some eyedrops, so the contact lenses, again, particular types of contact lenses, not just regular straightforward lenses, the same with spectacles and drops. So that's the conversation to have with the eye care professional to say, okay, what options are available in my jurisdiction, what's available to me, and what's going to work best for my child in terms of lifestyle. So maybe the child is a gymnast, in which case, spectacles are maybe not going to be the best thing. Or maybe the child is a swimmer, in which case, perhaps soft lenses are not the best thing because you can't wear lenses in the pool. Maybe my child is completely freaked out by the thought of contact lenses, they just want the spectacle lenses, but perhaps they are really young, and we want to add drops in as well. So there's that conversation, to custom design, the best method of management for the child happens between the parent, the child, and the eye care professional.

Denise Balch: 15:48

I think that's excellent information, because as a parent myself, I wasn't aware of the option for eye drops. And so that's very interesting. What about eye examinations for children? Because we haven't really talked about that yet. So when should a parent first get their child or they're infant's eyes examined.

Doctor Deborah Jones: 16:12

So the recommendation that comes out of the CAO and other authorities on eye care says, first eye exam should be at about six months of age, which, you know, parents often are completely shocked, they say, well, what are you going to do at six months? And that's really just to make sure the child is on track. So obviously, all the testing is objective, you know, we're not asking a six month old to read the chart. But we can check to make sure the eyes are working together, everything looks healthy, and everything looks on track. And then the recommendation is somewhere around two to three years of age. And then basically, annually, kind of at school age. I actually usually say six months, and then annually, because I think parents get it into their head, okay, September is the time I take my child, and they just, you know, register every September, it's time to have an eye exam again. So you need to talk to, again, your eye care professional, make sure they're comfortable with seeing children at that age, which most should be. If they're not, maybe they're specializing in a different area of optometry, and perhaps not as familiar with children then ask for a recommendation of somebody that does see children and is very comfortable with the younger age group. And then obviously, once we get into the school age, it's a lot easier to examine a child, you know, you get some feedback from them. But a lot of the testing is still objective. So you don't have to worry if a child is not very good at their letters, or isn't very confident with reading, we can still have a really good look in a good assessment, particularly of that prescription. Are they bordering on being myopic, so we also know that we expect young children to be far-sighted, so we expect them to have a positive prescription. So their eyes do a little bit of extra focusing as they're younger, and then they tend to outgrow that. And if we're not seeing that positive prescription in a young child, then we are certainly more alert to the fact that they might be about to board that myopia train, they might be just about to step on it. And then we can perhaps recommend a shorter recall time, maybe we'll see that child in six months, rather than leaving them for the full year. So the take home message

is: 18:28

always, absolutely, get those children in for eye examinations and make it a regular thing, not, oh, I did it at three and now I'm bringing them back at eight. It needs to be just like the dentist, you know, you get them in regularly.

Denise Balch: 18:42

Yes, I think often, when we're a new parent, we may not even think about having our child's or infant's vision examined. But obviously it's important to do that and to catch any visual irregularities including myopia as early as possible. And of course, corrective wear would generally be covered for both adults and children under a group benefit plan, so people should check their group benefits coverage as well.

Doctor Deborah Jones: 19:14

And of course, dependent upon what province you're in, so I work in Ontario, and children's eye care is covered through OHIP. So there shouldn't be a financial barrier to having your children's eyes examined.

Denise Balch: 19:27

Great. Now, if parents would like to learn more about childhood myopia, there are sources are there sources that you can recommend?

Doctor Deborah Jones: 19:38

The best source is your optometrist, hands down, that's the individual that knows the most about eye care, and will be able to certainly direct a parent on to the best management for their child. So I would always recommend, again, coming back to how important eye examinations are and having that discussion. In terms of other resources, I think parents often have good access to online parenting resources, and there's lots of myopia information available. Again, just like all of the Google searches, you need to be a little bit careful on what you're reading, and certainly circle back to a professional. The Canadian Association - opto dot CA - has some information on myopia. And while they can't provide specific information to patients or parents, they can certainly perhaps guide them to another resource if somebody has specific questions. But lots and lots of resources. And obviously, this podcast is a resource, so hopefully we shared lots of information that will really encourage people to make sure they have their children's eyes examined. And if there is myopia, don't accept that just a regular pair of spectacles is the way to go. Because we have much better options now for children to try and slow down that progression

Denise Balch: 21:00

Great, and, of course, many of those are covered under the group benefit plan, so it's important to explore your coverage options as well. And for plan sponsors, I know many employers, they're big into wellness these days and want to educate their employees. And certainly, once again, if you are looking for additional resource information or referrals on how to create some communications to your employee population, and certainly give the Canadian Association of Optometrists a shout, and they will be more than happy to redirect you to the appropriate resources. So Debbie, Dr. Jones, thank you so much for being with us today, I really appreciate the insights you've been able to provide to us about myopia. I think everybody would have learned something from the discussion that we've had today. And once again, thank you for sharing your insights and your valuable time.

Doctor Deborah Jones: 21:54

You're absolutely welcome, and it's been my pleasure to be with you. Thank you so much for the opportunity.