Despite all my best efforts to boot G1 out of the house and give him more sunlight exposure, it appears we have not done enough. It probably doesn’t help with his strong genetic component. In the six months since his last eye check, his myopia has progressed significantly from -0.25 in one eye to -1.00 in both. He also has mild astigmatism in one eye.
As I watched while G1 had his eye test, I could tell that things were not going well. Even so, it was still a blow to the gut when the optometrist revealed his results. Plagued with short-sight since I was about G1’s age, I had so hoped to at least delay the onset of his myopia.
Well, we can’t change what’s already happened, but it is important that we try to reduce the progression because moderate to severe myopia can increase the risk of developing serious eye problems, such as retinal degeneration and retinal detachment. What’s moderate to severe myopia? Moderate myopia is any reading from -3.25 to -6.00. Above -6.00 is considered severe myopia.
What can we do to reduce the progression of myopia?
Currently, the only known way to decrease the likelihood of developing myopia is to spend time outdoors. Previous articles have stated that it isn’t certain what it is about being outdoors that prevents myopia. They suggest possible factors such as:
- more distance vision use
- less near vision use
- physical activity (although this study rules this one out)
- exposure to natural ultraviolet light
But I recalled reading that it was exposure to the intensity of natural light that reduces the risk of myopia, so I reviewed the literature again…
Exposure to Sunlight Reduces the Risk of Myopia in Rhesus Monkeys (PLoS ONE – June 2015):
…our study demonstrates that exposure to natural light has an effect to reduce hyperopic defocus-induced myopia, supporting a role for sunlight in protection against myopia by outdoor activity in school-aged children.
New Research an Eye-opener on Cause of Myopia (CNN – June 2011):
Our hypothesis that the mechanism of the effect of light was mediated by retinal dopamine, a known inhibitor of eye growth whose release is stimulated by light, has also been supported by animal experiments.
Why are we Short-sighted? (BBC – January 2015):
A more widely accepted idea is that sunshine triggers the release of dopamine, directly in the eye itself. Short-sightedness is caused by excessive growth of the eyeball, making it more difficult for the lens to focus an image on the retina, but dopamine seems to put the brakes on this and keep it in a healthier shape.
Meanwhile, The College of Optometry (Ohio State University) will be focusing their research on the variables that have the greatest potential for being the reason natural light exposure reduces the incidence of myopia: invisible ultraviolet B rays (UVB) and vitamin D, and visible bright light and dopamine.
Okay, so I stand corrected. Dopamine seems the likely reason, but it is not a determinant factor for preventing myopia. Whatever the reason it works, it is a fact: spending more time outdoors = reduced myopia. And, of all the methods tested for slowing the progression of myopia, spending time outdoors is still the most effective. So even though G1 has developed myopia, we should still try to maximise his outdoor time.
Myopia Progression Intervention
What else can we do? Well, at the point of writing this article, there are four types of treatment demonstrating promise for controlling myopia:
- Atropine eye drops
- Multifocal contact lenses
- Multifocal eyeglasses
- Orthokeratology / corneal reshaping
Atropine Eye Drops
I’d never heard of this one until I read about it online. Of all the interventions for reducing myopia progression, this appears to have the largest positive effect. The biggest concern is the uncertainty of the long-term impact of using this medication and the potential side effects, such as eye discomfort, light sensitivity, and blurred vision. It’s probably moot to discuss even this option because I don’t think it’s even available. You can read more about atropine here.
Orthokeratology / Corneal Reshaping
More popularly referred to as Ortho-K, this treatment involves wearing special contact lenses at night. During the day, the lenses are removed, and your vision is corrected. Ortho-K works by reshaping the eyeball while you sleep. It is not a permanent corrective measure, and you will need to keep wearing the lenses at night to have continued eye-corrective effects.
I remember hearing about this years ago when I was still in University. At that time, I was skeptical because I didn’t know what the long-term effects might be. Now that they have been in use for so many years (giving away my age), I guess they should be pretty safe to use.
But… Contact lenses for kids? Is that wise? Well, it seems contact lenses have been used in infants with congenital cataracts and other eye conditions. Children as young as 8 to 11 years old tolerate them pretty well and are quite capable of handling them without help from their parents. The considerations of contact lenses for kids, therefore, depends on individual factors, such as how well your child handles responsibilities, such as household chores, keeping his room clean, personal hygiene practices, etc.
Eye infections can be a real problem if your child doesn’t take adequate care with his contact lenses. I would not recommend them if there is even a question about personal hygiene practices. Daily disposables are a safer bet for kids. Ortho-K lenses are not disposable and require proper cleaning and disinfecting every morning, so your child needs to be diligent about looking after them.
Multi-focal lenses (also referred to as progressive lenses or PAL) have different powers at different zones of the lens, with the top of the lens (for distance vision) at the full corrective power with a progressive decrease towards the bottom of the lens (for near vision). Studies have shown them to have some effect in slowing the progression of myopia, although the results are varied. Multi-focal contact lenses appear to be more promising than multifocal spectacles while the results for multifocal spectacles are mixed. In fact, given the significant cost of multi-focal lenses, it is not recommended for routine treatment.
The Correction of Myopia Evaluation Trial (COMET) looked at the effect of PALs compared to single vision lenses on myopic progression. The study involved 469 subjects, age six to 11, with myopic prescriptions between -1.25 and -4.50 spherical equivalent. Over the course of three years, they found a statistically significant difference between PAL and single vision lenses of 0.20 D.
Soft multifocal contact lens wear resulted in a 50% reduction in the progression of myopia and a 29% reduction in axial elongation during the 2-year treatment period compared to a historical control group.
If you want to slow the progression of myopia, there is one thing you shouldn’t do – get undercorrected lenses. There is a general premise that we can reduce myopia progression by getting the optometrist to prescribe weaker lenses. The research, unfortunately, shows that this has the opposite effect of increasing the progression of myopia.
The data shows undercorrected children progress faster in their myopia – therefore, it is preferable to give children an updated prescription as soon as their eyes change to help stabilize their vision as best as possible. – Review of Optometry
The Bottom Line
Until further studies emerge, these are the best methods currently for reducing the progression of myopia:
- increased outdoor exposure
- ortho-k or bifocal soft contact lenses
Let’s see how responsible G1 is with his glasses before we make a decision on the contact lenses.
For further information, see also: A Comprehensive Guide to Myopia