– Treatments for Myopia –
Orthokeratology for myopia control
Orthokeratology is the most common and most popular option selected by patients and parents for the treatment of myopia. The aim of treatment is to slow the progression of myopia (also known as ‘myopia control’). Orthokeratology, or OrthoK, are rigid contact lenses that are worn overnight and gently mould the cornea (the front clear surface of the eye). This means that, when the cornea is moulded to a flatter shape, the eye becomes focussed with the need for glasses. So no glasses or contact lenses are required for vision during the day! This keeps active children free to be kids everyday – they can play sports without glasses, jump in a swimming pool, do karate or gymnastics, even just wear normal sunglasses outdoors. The only thing required is that the contact lenses are inserted every night to maintain the clear vision the next day.
Even though this has many great benefits for your child’s lifestyle, the best benefit is the myopia control effect of orthokeratology. Many studies have conclusively shown that these orthoK lenses can also work to slow down myopia progression1. It is because of the shape moulded across the cornea with orthokeratology lenses. Although it focuses light centrally on the retina, it defocuses peripheral light in front of the retina. This optical effect is what is theorised to stop the eye from growing longer and has now been duplicated in soft contact lenses and glasses. But orthokeratology is the original myopia control option for children, and the one practiced most often because of it’s fantastic benefits:
Benefits of Orthokeratology for myopia
- Many studies supporting the evidence of orthokeratology as one of the most effective forms of myopia control
- No glasses or contact lenses needed throughout the day
- Contact lenses are only worn at night, under parental supervision
Although children are most often sceptical about whether they can handle or wear contact lenses, most take to lenses easily after some practice. Every child is different and some do require more education and practice than others, but more than 95% of the children we recommend orthokeratology lenses are successful in wearing the lenses. But for those who are hesitant, the fitting process does include an overnight trial of the lenses, in order to ascertain whether your child is a good candidate for the treatment option.
Multifocal Soft Contact Lenses
Another form of treatment to prevent myopia progression is soft multifocal contact lenses. These are designed to emulate the optics of orthokeratology contact lenses. These soft lenses are for children who are sceptical about sleeping in lenses or perhaps find the rigid material of orthokeratology lenses a “deal-breaker”. Parents who wear soft contact lens also understand the wear schedule of this treatment option better, and this option is often selected as an easier option for a family to introduce into their busy lives.
Like orthokeratology contact lenses, these soft multifocal lenses focus light on the central retina for clear vision, but defocus peripheral light in front of the retina for myopia progression prevention. Also, like orthoK, multifocal soft lenses wearing children are also free of their spectacles during the day, great for most sports (although there are limitations with swimming).
Soft lenses are very easy for young children to adapt to, as their soft material makes them comfortable within just a few minutes of insertion. If anything, the biggest sensation a child will have with the insertion of a soft lens on eye is the feeling of water, like a raindrop has fallen into their eye. After a few blinks the lens clears and is quite comfortable to wear all day. Insertion and removal of lenses is something that requires some practice, but children do pick up the skills easily with time. And a child would never leave the Myopia Clinic with soft contact lenses without being proficient at these skills, even if it takes a few sessions of teaching. Having taught children as young as 4 years old and adults as old as 92 years old the art of contact lens handling, we pride ourselves on teaching these skills in our one-on-one sessions to make sure your child’s contact lens journey is successful.
Myopia Control Glasses
For years, optometrists have wanted to prescribe glasses that were able to slow down the progression of myopia in their patients. Although the contact lens options for myopia progression prevention are wonderful, many children and parents aren’t keen to try them, so having an option for myopia control in glasses has been sought. Many studies have explored bifocal and progressive lenses as a means of controlling myopia, however the effect of these correction options has been limited, with as little as 0.25D reduction in progression per year1. Also ‘under correcting’ Myopia in spectacles is now an outdated treatment and has actually been shown to mildly increase the rate of Myopia progression, and therefore is not a viable option for myopia control.
Recently, several companies have launched new lens designs that have been created to mimic the optics on the retina that orthokeratology contact lenses create. Simply explained, the centre of the glasses lenses have the child’s full myopia prescription to provide clear vision for daily tasks. However, the periphery (edge) of the glasses lenses are either under-corrected or blurred in some way, to prevent the eye from growing longer by not focussing light on or behind the peripheral retina (something that is done by standard single vision glasses). One example of these new design spectacle lenses is called ‘MyoVision’ (produced by Zeiss). Early studies show these spectacle lenses do have an effect of slowing myopia progression in younger children (ages 6-12)2.
There are several pros and cons for this option of myopia control:
Advantages of myopia control glasses
- Ability to introduce optical myopia control in those children who may be unable or don’t wish to wear contact lenses
Disadvantages of myopia control glasses
- Not the most effective for myopia control
- Spectacles need to be worn full-time
Atropine for the treatment of myopia
Atropine treatment for myopia involves the daily use of medicated eye drops to slow the progression of myopia. Atropine eye drops have two temporary effects when used on eye: they make the pupils larger (pupil dilation) and create an inability to focus on close objects (cycloplegia). How great this effect is and the length of time this temporary effect lasts depends on the concentration of the eyedrop. Typically, atropine given in bottle by the chemist or used in office to dilate pupils is either 1% or 2%, which creates a very strong effect in the eye. However, for children, the drop is made in Australia by a compounding pharmacist and the concentration is reduced to between 0.01% to 0.05%, a fraction of the full-strength version. This then creates a very small focussing and pupil dilation effect, that is not noticed much by the child. However, this mild effect has been shown in research to significantly inhibit the growth of the length of the eye, thereby reducing the progression of myopia. But in order to have a lasting effect in preventing the progression of myopia, these drops must be used for at least 1-2 years.
Advantages of atropine treatment:
- Relatively simple treatment for myopia – 1 drop per day in both eyes (usually before sleep)
Disadvantages of atropine treatment:
- Must be used every day for at least 1-2 years
- Possible glare/light sensitivity from mild pupil dilation
- some reported cases of systemic effects including dizziness and nausea, as well as hypersensitivity reactions
Comparing Treatment Options for Myopia Control
This small table represents a comparison of myopia control treatments (a compilation of 30 studies). The percentages of reduction show how much children with that treatment option progressed compared to children who did not use a myopia control treatment option.
|Treatment||% Reduction of Progression|
|Atropine (medicated eye drops)||45|
|Multifocal soft contact lenses||33|
|Progressive/bifocal lenses in spectacles||12|
|Single vision spectacles||0|
*data compiled using meta-analysis by Huang et al. 3
1. Li SM, Ji YZ, Wu SS, et al. Multifocal versus single vision lenses intervention to slow progression of myopia in school-age children: A meta-analysis. Surv Ophthalmol 2011;56:451–460. [PubMed]
2. Sankaridurg, P.; Donovan, L.; Varnas, S.; Ho, A.; Chen, X.; Martinez, A.; Fisher, S.; Lin, Z.; Smith, E. L.; Ge, J.; Holden, B.; Holden, B. “Spectacle Lenses Designed to Reduce Progression of Myopia: 12-Month Results.” Optom. Vis. Sci. 2010, 87 (9), 631
3. Huang J, Wen D, Wang Q, et al. Efficacy comparison of 16 interventions for myopia control in children: A network meta-analysis. Ophthalmology 2016;123:697–708.
Although not a lot of research has been completed in the area of combined therapies, early results of studies where therapies are combined (for example atropine drops used in conjunction with orthokeratology lens wear) are very promising, showing rates of axial length progression even slower than either therapy individually. This proactive option is usually reserved for children with long axial lengths and a strong family history of myopia, who require more aggressive treatment options to prevent their myopia progression.
Prevention of myopia
Visual hygiene tips
In the last few years several studies have come out that have explored the environment in which myopia is most likely to progress. While the best option for myopia control involves a scientifically supported treatment, we know from recent studies that certain visual habits and environments result in less myopia. A few tips for healthier eyes are:
- Spend more time outdoors: if children spend at least 40 minutes outdoors each day they are less likely to develop and have
- Take breaks when doing near work: the 20/20 rule- every 20 minutes take at least a 20 second break.
- Limit screen time: less than 3 hours screen time/day if possible. Also make sure that iPads and phones are held a suitable distance away when viewing.