Myopia progression in young adults

It is very common to see children develop myopia and get worse over time. We know that adults typically don’t have myopia progression because their eyes have fully developed and stopped growing, just like their height. However, in real life, some young people do have increased prescription numbers year after year. Researchers observed that college students continue to have increased myopia previously in Europe and the US. Now a new study [1] from Australia followed young people for 8 years (20 to 28 years of age) and confirmed this finding.

Among 516 subjects with no myopia, 14% were found to have developed myopia after 8 years. Among 698 subjects with myopia less than 6 diopters, 0.7% were found to have developed high myopia (more than 6 diopters) after 8 years. Among 691 subjects who were included in the progression analysis, 37.8% had myopic shift of 0.50 D or more. On average, the myopic progression was -0.04 D (ranging -0.03 to -0.06) per year, and axial length increase was 0.02 mm (0.014 to 0.025) per year. 

We can see that this is a small myopic shift, but it is a true shift and statistically significant.

So what kind of people are more prone to develop this myopic shift as adults? They found that East Asians were more likely than whites, females were more likely than males, those with myopic parents were more likely than those without myopic parents, and those who spend less time outdoors were more likely to develop more myopia as adults. Interestingly, they used an objective way to evaluate outdoor activities, conjunctival ultraviolet autofluorescence area, as the larger the area, the longer exposure to the sun.

These are also the risk factors of myopia progression in kids. So having myopic parents, being a female, being an East Asian, and spending less time outdoors are just not good in terms of myopia, kids or adults alike. You will notice that no one can change the first 3 risk factors, but the last one is highly modifiable. 

The take home message is that myopia progression can continue into adulthood, though at a much slower rate. And spending more time outside is always a good thing if you don’t want your glasses to get thicker.

Reference: 

[1] Lee SS, Lingham G, Sanfilippo PG, et al. Incidence and Progression of Myopia in Early Adulthood. JAMA Ophthalmol. Published online January 06, 2022. doi:10.1001/jamaophthalmol.2021.5067

Low dose atropine drops and ortho K combo work better than ortho K alone in myopia control

Many parents ask whether their children should be on both atropine and ortho K to control myopia. There were small studies, some showing better result with the combo treatment. There was also a small scale study that I talked about that showed when ortho k failed to control myopia progression, additional atropine did not help.

Now a new research that analyzed 5 clinical studies involving 341 children revealed that ortho K + low dose atropine worked better than ortho K alone in controlling myopia progression [1]. On average, using the combo treatment results in 0.25 mm axial length elongation compared to about 0.35 mm in ortho K alone after 12 months of treatment. This is a small, but statistically significant finding.  

I think having this data is helpful. When a child has sub-optimal control with ortho K alone, I can recommend adding atropine. If a child has fast progressing myopia and parents are anxious, I can recommend starting with both treatments to maximize the control.

Would you be interested in seeking both treatments together right from the beginning?

Reference:

[1]https://journals.lww.com/claojournal/Fulltext/2021/02000/The_Efficacy_of_Atropine_Combined_With.7.aspx

10 year use of low dose atropine for myopia control

We know that low dose atropine has been used to control myopia progression for a number of years now. It is still not approved by the US or Chinese FDA partially because long-term safety data are lacking. Previous studies demonstrated 2 years of using to be safe and effective. But myopia control is a long-term thing, maybe up to 10 years if a child starts to develop myopia from an early age (6- 8 years of age). 

Well now there is a study in Taiwan following children using low dose atropine for 10 years. This is a cohort study, no controls, and with only 23 subjects. Every child (that had myopia) was on low dose atropine for the entire 10 years and monitored every 2-4 months to check their refraction and axial length. It is certainly not a controlled or randomised study, and with a low sample size. However, I think it gives us a lot of information in a clinical setting on what to expect once a child is on low dose atropine for myopia control long term.

They also adopted a commonly used clinical approach, stepwise increase in treatment dosage if the treatment effect is not enough. For example, every myopic child started with 0.05% atropine. If a child did well on this, they continued this dosage throughout the 10 year period. If however their myopia continued to progress more than 0.50 D every 6 months, then they were switched to higher concentrations of 0.1%, 0.25%, and until 0.5%. A high concentration of 1% was not used.

In my clinic (and perhaps many others), I usually start with even lower concentration, 0.01%, which has been clinically proven to be effective in myopia control and with the least side effects including pupil dilation, light sensitivity and blurry near vision. I would go up to 0.02% and 0.05% if myopia control is not achieved, and I seldom go higher than 0.05% because at this point the side effect is noticeable and may interfere with normal study and life of a child. Eye doctors in Taiwan are more aggressive in myopia control in terms of using atropine and I thank them for the study. I always wonder whether I should ramp it up, and if higher concentrations are effective, then maybe it’s worth the side effects (and potentially risks of using this for 10 years).

This study answered my question to some degree. First of all, 65% patients were only using 0.05% atropine throughout the study, which means 35% patients did not respond well to the initial low dose. This is a high number. Remember 0.05% is already a higher concentration than the most commonly prescribed 0.01%, and still ⅓ of children do poorly on it. When we encounter children like this (and we will), do we further increase the dosage? In their study they did, and what they discovered was that for those who did not do well in the initial low concentration of atropine, despite the stepwise increase in the atropine concentration, their myopia control was still worse than the kids who responded to the initial low dose atropine. There were vast inter-individual differences, but the mean numbers look like this: the responding kids started with -1.5 D and progressed to -4.7 D after 10 years, whereas the poorly responding kids started with -0.9 D and progressed to -6.6 D. Their study did not have a control, but based on natural history of myopia progression in their population, they predicted about -7.7 D if no myopia control was done at all. So for those that respond to atropine, a reduction of 3 D of myopia over 10 years is quite good, especially it prevents these kids from developing high myopia (more than -6.0 D), which is associated with more retinal related complications. On the other hand, 10 years of high dose atropine in children who were poor responders resulted in only 1 D of myopia reduction, it seemed less worthwhile, considering the burden of using drops daily for 10 years and the side effects associated with dilation. Of course, this is purely based on a mean value, and individuals can be quite different, and for some, maybe 1 D reduction is still something that helps. 

But the lesson here is that if a child responds poorly to low dose atropine, merely increasing the concentration may not be the answer. They may be better off with additional or alternative control methods, such as ortho K lenses or multifocal soft contact lenses. 

Another outcome is that they did not find significant side effects with 10 year use of low dose atropine drops. The study also claimed that the children were not prescribed PALs. That is interesting, considering that atropine at concentration of 0.1% or above will have significant dilation and cycloplegic effects. Given that they used higher concentrations, it can be assumed that 0.01% atropine can also be used without significant side effects for up to 10 years.

So the take home message is that long term use of low dose atropine (10 years) may be safe and effective, but if a child responds poorly to low dose atropine, then they may benefit more from other methods of control. But keep in mind that this is a limited study with small number of patients. We still wait for larger scale and better controlled study.

The study cited in this article:

Chuang, MN., Fang, PC. & Wu, PC. Stepwise low concentration atropine for myopic control: a 10-year cohort study. Sci Rep 11, 17344 (2021). https://doi.org/10.1038/s41598-021-96698-6

Can you use ortho K lenses and atropine together to control myopia?

We know that ortho K lenses and low dose atropine (0.01%) both can slow down the rate of myopia progression by about 50%. People often wonder whether by combining the two, we can slow down the progression even further.

Here is an article looking at a combo of the two in 73 Chinese children who have very fast myopia progression. They discovered that additional atropine 0.01% did not result in significant difference compared with ortho K lens alone in terms of axial growth.

This is disappointing. However, this study looked at children with fast myopia progression despite using ortho K lenses. Also only a small number of children were evaluated. In addition, this is a retrospective study, meaning authors looked at the data later, rather than a randomized controlled study, so there could be factors stewing the results.

Anyway, we await more studies to see whether the two have synergistic effect.

Reference:

Chen Z, Zhou J, Xue F, et al, Two-year add-on effect of using low concentration atropine in poor responders of orthokeratology in myopic children British Journal of Ophthalmology Published Online First: 11 March 2021. doi: 10.1136/bjophthalmol-2020-317980

Increased myopia among children during COVID-19

Covid-19 has really affected so many aspects of our lives. With all that isolation inside, and the remote learning with digital screens, parents worry about their kids’ health. Many worry this will do great havoc to their eyesight, and they are not wrong.

Research has shown that confinement to home due to covid-19 is associated with an increase in myopia. Scientists have been monitoring the refractive error of 123 535 Chinese children since 2015. While the refractive error was showing a pretty steady trend in kids 6 to 8 years of age from 2015 to 2019, there was a sharp and dramatic change toward myopia in 2020 (Figure 1). Many Chinese children already don’t get enough outdoor activities and spend way too much time studying, and the covid-19 put extra strain in terms of even further decrease of outdoor time and increase of screen time.

Figure 1. Young children show a dramatic increase in myopia in 2020 compared to previous years [1]. Figure from reference [1]

I only hope that with universal vaccination and a good hygiene habit that we have formed during the past year, children will be able to be back to school and enjoy normal outside activities soon. If you think you child may have trouble seeing, please bring them to an eye doctor.

[1] Wang J, Li Y, Musch DC, et al. Progression of Myopia in School-Aged Children After COVID-19 Home Confinement. JAMA Ophthalmol. 2021;139(3):293–300. doi:10.1001/jamaophthalmol.2020.6239

Myopia and anxiety

A friend who is a rehabilitation therapist in China told me some interesting observation he has had while treating myopic children. He noticed that for those children who are more anxious, their myopia progressed faster, versus those who are calmer. So he asked me whether anxiety and other psychological factors may contribute to myopia development and progression.

Now I know that when I was 10 and started becoming myopic, I had a lot of anxiety and depression, for the reason that I could not see the blackboard in class! Every school year we went to the hospital to have physical exam and the vision exam was the most anxiety-inducing. I would squint, guess, and peek at the tumbling E beforehand trying to memorize them. My face became red and my hands sweaty. Yes I am ashamed to admit that I cheated in the vision screening in elementary school to get away with a failed report to the teacher and my parents. Why did I do that? As a child I could not describe it exactly. But I did not want to wear glasses and became different from everyone else. Plus, as a straight A student, a failed test in any form was not acceptable.

More and more I found it difficult to see the board. I would nonchalantly walk up to the board then back to my seat (fortunately I sat in the middle so did not have to walk too long to disturb the other students). I would peek at my desk mate’s notes to see what’s going on. I became afraid of math classes because the numbers were small. Eventually I had to tell my parents that I had trouble seeing the board. I remember feeling ashamed when I had to tell them. It’s as though I contracted a disease that I should not have. Though the science at the time was not clear, at least to me, I knew that I was to blame for becoming near-sighted. I was always reading, day and night. Not necessarily school-related, but I was hooked by fictions, story books, magazines and newspapers, anything that had prints on them. Outside classroom, I would read on my own. During summer and winter vacation, I would still be reading books from the library. My dad who’s a teacher and scholar, was the role model that I took after. He did not stop my prolonged near work. My childhood home was very dark, with rather dim lighting. Plus my dad also had myopia though my mom had hyperopia. Thus odds were really against me and no surprise I was among the early ones in my class to wear glasses. That was in the early 1990s, at age 10 I developed myopia while majority of my classmates were still emmetropic. Today probably majority of kids in a 4th grade classroom are wearing glasses. Times have really changed.

I remember going to the hospital to have my eyes examined. The doctor put eye drops in my eyes, I had to wait for a long time, before someone put a strange-looking frame on my face and showed me a bunch of different lenses. I was asked to read letters on a chart, and I felt strange that I was able to see some tiny letters. I had to say that this cycloplegic trial frame refraction was up to American standard even to this day. Thanks to my small town ophthalmologist, I was finally able to see. I was -2.00 in both eyes that day and I no longer had to walk up to the board to see small prints.

Back to our question on myopia and anxiety. My own experience told me that as a myope without glasses, I definitely felt anxiety. After wearing glasses, my vision was back, but I felt a kind of depression because I had to rely on glasses and I hated having to glasses. I went through all 5 stages of grief: denial, anger, bargaining, depression and acceptance. I thought that if I looked far away long enough, my eyes would be back to normal. I was mad at myself for abusing my eyes without a break on those stupid books. I constantly regret it and promised I would trade in some years of my life in exchange for normal eyesight. I was depressed that I had to wear glasses and looked ugly. Eventually of course I accepted this imperfect aspect of me. After all, there were so many other things that were not perfect so why focus only on myopia?

As an optometrist, myopia is one of the most common conditions we treat. It’s so common we almost consider it ‘normal’, routine and benign. We rarely considered the psychological aspect of myopia, when in reality this condition hit children and adolescents, who are at a vulnerable age.

Now the science part of this article. Research has shown that myopic teenagers had more anxiety than their peers, and boys with myopia had more anxiety than girls with the same condition 1. However, personality profile and psychophysical stress do not seem to play a primary pathogenetic role in myopia 2. So that is good, you can feel tortured by the fact that you need thicker glasses, but the sadness alone does not make your eyesight worse.

References:

1.            Łazarczyk JB, Urban B, Konarzewska B, et al. The differences in level of trait anxiety among girls and boys aged 13-17 years with myopia and emmetropia. BMC Ophthalmol 2016;16:201-201.

2.            Angi M, Rupolo G, De Bertolini C, Bisantis C. Personality, psychophysical stress and myopia progression. Graefe’s Archive for Clinical and Experimental Ophthalmology 1993;231:136-140.

Will eating sugar make myopia worse?

Myopia has become a global epidemic, affecting kids of school age, sometimes as early as 6 or 7. Left untreated, myopia may progress 1 diopter each year, resulting in high myopia when kids become adults. Myopia is not just an inconvenience, it is an eye disease that significantly increases a person’s risk of developing retinal detachment and myopic macular degeneration, both can lead to blindness.

Naturally parents become concerned when their kids fail the vision screening at school and have to wear glasses to see well. As food is a key part of our health, many often wonder if food contributes to myopia development. For example, does eating sugar and refined carbohydrates increase myopia? Surely sugar is bad for your teeth and just bad for your health in general. Is it also to blame for myopia?

Will sugar coma cause you to see worse?

When I was a student at New England College of Optometry in Boston, we learned extensively on myopia, which is a major topic of interest for optometry. While many factors affect myopia, for example, genetics, prolonged near work, lack of outdoor activities, sugar intake was never mentioned as a factor to affect myopia. Yes diabetes can affect a person’s vision by making them temporarily more myopic or hyperopic, but that is reversible and after blood sugar levels are controlled, the eye returns to baseline refractive state. Most people, especially school aged children, do not have diabetes or constantly fluctuating sugar levels. So is there any evidence for a role of sugar in myopia that is not in context of diabetes?

It turns out not many studies have been done on this topic. In 1956, Gardiner proposed that carbohydrates and fats in the diet could cause myopia 1, but this hypothesis was discarded later in the scientific community. When this happens, it’s either because not enough research was done to support it, or that it did not hold water by subsequent research. In deed there was a scarce of literature on this topic. But one actually found that more sugar intake did not increase risk of developing myopia in children 2. This study in turn, found out that too much saturated fatty acid in the diet correlated with more myopia.

Most recently a French study evaluated 180 children aged 4-18 via questionnaire about their diet habits, and discovered that for girls, more sugar and refined carbohydrates correlated with more myopia, but in boys, this was actually the opposite, that is, when boys eat more sugar/carbs, they show less myopia development 3. This type of study has flaws in that it relies on questionnaire which can be highly subjective. In addition, many variables were not controlled, such as outdoor time, reading and screen time. Even if it’s to be trusted, the study like many epidemiological studies, evaluate a correlation, not causation. Besides, how do you interpret the data that sugar reduces myopia risks in boys? Would you recommend boys to eat more sugar and refined carbohydrates? I don’t think so.

In summary, little evidence exists to indicate sugar or refined carbs increase or decrease risks of myopia. Maybe this is just a factor that has not much to do with myopia. To advocate better oral hygiene and health, we certainly want children to control their intake of sugar and refined carbs, possibly for everyone really, not just kids. However, if you think that by eating less sugar you will not develop myopia, you are up the wrong tree.

References

1.            Gardiner PA. The diet of growing myopes. Trans Ophthalmol Soc U K 1956;76:171-180.

2.            Lim LS, Gazzard G, Low YL, et al. Dietary factors, myopia, and axial dimensions in children. Ophthalmology 2010;117:993-997 e994.

3.            Berticat C, Mamouni S, Ciais A, Villain M, Raymond M, Daien V. Probability of myopia in children with high refined carbohydrates consumption in France. BMC Ophthalmol 2020;20:337-337.

Does ortho K increase risk of glaucoma?

The ortho K lens is popularly used to reshape cornea, correct vision and slow myopia progression. Read my previous post here (https://bostoneyeblink.com/2016/09/09/ortho-k-why-do-it-and-is-it-risky/)

People are often concerned about potential side effects or complications of wearing ortho K lenses. We previously discussed that corneal infection is a concern, but proper hygiene and care minimize this risk. It is a hard lens that touches on the cornea, will this have any effect on glaucoma or eye pressure of the eye? A colleague of mine recently saw an 18 year-old patient interested in ortho K for his myopia, who has a family history of glaucoma, and showing some questionable visual field finding himself. My colleague is worried about what ortho K may do to patient’s eye pressure and risk of glaucoma.

First of all, glaucoma is exceedingly uncommon among kids and young adults. Second, even if someone has glaucoma, it is not a contraindication for wearing ortho K lenses. Research has actually shown that wearing ortho K lenses overnight reduced eye pressure slightly [1, 2].

Of course, if you have glaucoma, you need to regularly see your glaucoma doctor to check eye pressure, health status of the optic nerve and visual field function, whether you wear any type of contact lens including ortho K lens or not. But people with or without glaucoma, if eligible for ortho K lenses, can certainly choose to wear them.

References:

[1] M.R. Romano; A. Calossi; F. Romano; G. Ferraioli, Intra–Ocular Pressure After Overnight Orthokeratology, ARVO Annual Meeting Abstract, Investigative Ophthalmology & Visual Science May 2006, Vol.47, 2391

[2] Chang CJ, Yang HH, Chang CA, Wu R, Tsai HY. The influence of orthokeratology on intraocular pressure measurements. Semin Ophthalmol. 2013 Jul;28(4):210-5. doi: 10.3109/08820538.2013.768679. Epub 2013 Apr 29. PMID: 23627528.