Why is myopia a concern?
The rate of myopia is growing across the world, increasing from 22% of the world’s population in 2000 to 33% in 2020 – half of the world’s population expected to be myopic by 2050. Most myopia is caused by the eye length growing too quickly in childhood. When the eye gets longer (it’s axial length is higher), it stretches and puts pressure on the retina in the back of the eye. This delicate retinal tissue is responsible for sending images to the brain that result in clear vision. When the retina stretches, it’s prone to damage. Excessive eye growth raises concern because even small amounts of stretching can lead to increased likelihood of vision threatening eye diseases in later life. For this reason, a child with myopia is significantly more likely to suffer from sight-threatening diseases and conditions like cataracts, macular degeneration, glaucoma and retinal detachment later in life. “Myopia isn’t just a blurry vision thing.”
Why is axial length so important in Myopia Management?
A patient’s prescription is NOT the best way to determine the best route for treatment. It is also NOT the best way to monitor progression.
Example: Julie – who has a higher prescription – is actually at a lower risk for high myopia than her brother Julien – who has almost half the prescription of Julie. This is due to their axial length (length of their eyes). Julien’s axial length put him in the 90th percentile for developing high myopia whereas Julie was in the ~ 60th percentile. Any child who is at or above 50th percentile must start treatment; however, Atropine eye drops will most likely be enough to control their myopia. For children in the higher percentiles, orthokeratology would be ideal. They may also need combination therapy with added Atropine.
Why manage myopia in children?
Myopia progresses fastest in younger children, especially those under age 10. This means that the most important opportunity to slow eye growth is when children are younger. Myopia management aims to apply specific treatments to slow the excessive eye growth to a lesser rate. Experts agree that myopia management should be started for all children under age 12, and typically continue into the late teens.
The short-term benefit of slowing myopia progression is that a child’s prescription will change less quickly, giving them clearer vision for longer between eye examinations. Lower prescription numbers also mean: Thinner lenses and better quality of life. The long-term benefit is reducing the lifetime risk of eye disease and vision impairment. This risk increases as myopia does with the good news being that reducing the final level of myopia by only 1 diopter reduces the lifetime risk of myopic macular degeneration by 40% and the risk of vision impairment by 20%.
Why haven't I ever heard of myopia control?
“I both love and hate this question. First, it gives me the floor to preach from my soapbox about the importance of myopia control — slowing down the worsening of childhood myopia — and the amazing options we presently have available. On the other hand, it casts a shadow on the real problem which is not enough providers offering what should be considered the standard of care. As myopia continues to sweep across the globe like a freight train off the rails, many eye doctors continue to prescribe spectacles in increasing strength to their patients every year. After all, we’ve been doing it that way since the 17th century. Every eye doctor on the planet gets concerned about eye health when they see highly myopic patients, yet we as a profession are reluctant to “blame” myopia for secondary eye diseases. Well that is all changing now. Experts across the globe have concluded with good evidence that myopia leads to further sight-threatening conditions. No patient or parent in this current world should ever have to utter the words “Why have I never heard of this before?” when learning about myopia control options.
Many eye doctors state their opinion that myopia control does not work. They represent the ones who have not tried it or worse, tried it without proper training and education. Myopia control does work. I see it each and every day in my practice and I try to teach other doctors about the power of myopia control.
The future is now and statements like “Why have I never heard of this before?” will hopefully become memories of the past.” – Dr. Paul Levine FIAOMC, FAAO
What are the treatment options for slowing myopia progression
Standard, single-focus long distance spectacles or contact lenses do not slow down the progression of childhood myopia. Instead, specific types of spectacles (not yet available in the US), contact lenses (specialty soft lenses and orthokeratology lenses) and eye drops called atropine have been proven to slow myopia progression in children.
The best option for your child will depend on their current prescription and other vision and eye health factors determined in their eye examination. Dr. Miller will discuss the options with you to determine the best option. Treatment options vary across the world due to availability, supply and regulatory reasons. It is important to note that no treatment can promise the ability to stop myopia progression in children, only to slow it down.
Standard single-focus contact lenses do not slow the worsening of childhood myopia but specific designs do. These specific designs can both correct the blurred vision of myopia and work to slow down myopia progression. The options include soft myopia controlling contact lenses and orthokeratology.
Risks and safety
Contact lens wear increases the risk of eye infection compared to wearing spectacles, with the risks being:
• 1 per 1,000 wearers per year for reusable soft contact lenses or overnight orthokeratology lenses9,10
• 1 per 5,000 wearers per year for daily disposable soft contact lenses
Risk factors for eye infection include not washing hands, not using the correct cleaning solutions, water exposure and not returning for regular eye examinations. With proper hygiene and maintenance procedures, this risk can be well managed. Other side effects of contact lenses to control myopia can be temporary adaptation to the different experience of vision, which typically resolves in 1-2 weeks.
There are many benefits to children wearing contact lenses:
1. Wearing contact lenses improves children’s self confidence in school and sport, and their satisfaction with their vision – as much as it does for teens
2. Children aged 8-12 years appear to be safer contact lens wearers than teens and adults, with a lower risk of eye infection
OPTION 1: orthokeratology contact lenses
Worn overnight and removed upon waking, such that no spectacles or contact lenses are required for clear vision during the day. They can require more appointments for fitting than other types of myopia control treatment. Adaptation to the lens-on-eye feeling can take 1-2 weeks but shouldn’t affect sleep. There are significant benefits for sports and active lifestyles, and since the contact lenses are only worn at home there is low risk of them being lost or broken during wear.
OPTION 2: Soft myopia controlling lenses
Worn during waking hours. They may be daily disposable, or reusable for up to a month. They typically require more appointments for fitting than spectacles but less than orthokeratology. Adaptation to the lens-on-eye feeling typically occurs in a few days. There are benefits in safety with daily disposables being the safest modality, and the number of lenses retained meaning loss or breakage is less of a practical issue.
Atropine eye drops
Atropine is an eye drop that is used to dilate pupils and has proven to be effective in controlling myopia. In a diluted strength, Atropine has shown to be effective at controlling myopia without being strong enough to actually dilate the pupil. It is important to note that contact lenses or glasses are still required to correct blurry vision when using Atropine eye drops.
Risks and safety
The risks and side effects of atropine are as follows:
• Potential side effects of increased sensitivity to light due to larger pupil size, which is typically resolved with light-sensitive glasses or sunglasses. One study found around a third of children requested these types of glasses, but this was the case even in the placebo (untreated) group.
• Problems with close-up focussing, which is typically resolved with glasses providing a stronger power for reading. One study found this only occurred in 1-2% of children treated with low-concentration atropine.
• Eye irritation or mild allergy, which can occur in 2-7% although this can depend on the formulation of the atropine.
Atropine can be toxic and even fatal to small children if it is ingested in high quantities by mouth, but high quantity absorption via the eye is unlikely. Medication safety in the home is extremely important.
Atropine eye drops are typically used at night time, before sleep, so are only utilized in the home environment. They are also ideal if the effective spectacle or contact lens options for myopia control are not suitable or not available for your child.
Spectacles (not yet available in the US, expected mid 2024)
Standard single-focus spectacles do not slow the worsening of childhood myopia but specific designs do. Myopia controlling spectacles can both correct the blurred vision of myopia and work to slow down myopia progression. They are safe to wear and adaptation is typically easy, with the only side effects being related to the limitations spectacles pose for sport and active lifestyles.