Myopia, also known as nearsightedness, has seen a rapid rise in Asia in recent decades.
In many East Asian countries, myopia is a major public health concern that affects between 80 to 90 per cent of high school graduates, of which about 10 to 20 per cent have sight-threatening pathologic myopia.
A very common disorder among children below 20 years, myopia occurs due to the elongation of the eyeball, causing light to converge in front of the retina rather than on it, resulting in difficulty seeing objects at a distance.
The longer the eyeball or the axial length, the worse the myopia. A study done in Malaysia shows that by the time a child is 7 years old, about 10 per cent of them are myopic, and up to 35 per cent are myopic by the time they are 15.
These figures have almost certainly risen since the start of thte Covid-19 pandemic, due to the increased amount of near work and screen time during the pandemic, coupled with little to no time spent outdoors — all of which are factors that contribute to myopia progression.
Why Is Early Intervention Crucial?
Myopia is a degenerative condition and patients with low myopia (nearsightedness of between -0.5 to -3.00 dioptres+) can progress to moderate or even high myopia (-6.00 dioptres and higher) if it is not properly controlled at an early stage.
The younger the child is when myopia sets in, the higher the risk of them developing severe sight-threatening complications in adulthood, such as glaucoma, cataract, retinal detachment, and myopic maculopathy which could lead to vision distortion, or even permanent blindness.
Even a 1.00 dioptre increase in myopia has been associated with a 67 per cent increase in the prevalence of myopic maculopathy. Conversely, slowing down myopia by just 1.00 dioptre can reduce the individual’s likelihood of myopic maculopathy by 40% (3).
Myopia is much like high blood pressure or diabetes; if left unchecked or untreated in the early stage, it could lead to serious vision complications later on in life.
Treatment Approaches For Myopia In Children
Myopia can be controlled with a combination of treatments and lifestyle modifications, provided it is detected early enough.
The types of treatments available for controlling myopia progression include:
- Spectacles: Myopic defocus, bifocals, multifocals and progressive lenses.
- Orthokeratology (Ortho-K) lenses: Used overnight, these are hard contact lenses worn by children before they go to bed. While asleep, the contact lenses reshape the cornea, so the wearers wake up to clear vision the next day without having to use any visual aid. However, the clear vision is only temporary, and tends to wear off towards the end of the day.
- Daily disposable lenses: Multifocal or dual-focus contact lenses that allow the wearer to enjoy clear vision while the lenses are in use.
- Atropine eye drops: Highly effective in myopia control, although side effects have been associated with higher doses. In Malaysia, atropine eye drops can only be prescribed by an ophthalmologist.
Recent findings indicate dual-focus contact lenses can offer significant benefits in terms of myopia control. Studies have found dual-focus lenses have yielded significant results in reducing eyeball elongation or axial length in children with myopia. Reducing axial length slows myopia progression in the wearer, in addition to providing clear vision.
Another study that compared the results of patients using orthokeratology lenses, dual-focus soft contact lenses, and those who did not use any interventions, found that both orthokeratology and dual-focus soft contact lenses were effective strategies in targeting myopia progression.
In practice, eyecare professionals (ECPs) may sometimes combine one or more treatment approaches to suit the preferences, lifestyle, and comfort level of the patient. We usually discuss the different available treatment options with the young patient and his or her parents, before recommending a course of action.
When it comes to lifestyle modifications our emphasis is on modifying the child’s day to day habits, and inculcating good visual hygiene habits from a young age such as minimising screen time, doing homework or reading under proper lighting, taking frequent breaks while doing near work, as well as spending more time outdoors and in the sun.
Contact Lens Safety And Usage In Children
Many parents opt for spectacles to treat myopia in their children, largely due to fears or concerns regarding contact lens safety. In reality, complications arising from contact lens usage is very minimal, and while there is a small risk of eye infections, it usually occurs when the wearer does not take the necessary steps for wearing contact lenses safely.
In my experience, even very young children of five or six years old are able to follow instructions on contact lens usage, such as washing hands before and after fitting the lenses, changing the lens solution regularly, and so on.
Disposable dual-focus contact lenses have a distinct safety advantage as they are easy to use and do not require special solutions, cleaning or storage. The wearer simply disposes them at the end of the day and puts on a fresh pair the next day.
An advantage of contact lenses over spectacles is that its treatment zones are always in focus. This means the child can enjoy clear vision whichever way they look.
With most spectacles, the wearer has to focus in a specific direction, in order for it to be effective, which can be a challenge for younger children.
Contact lenses are also useful in instances when the child is not comfortable wearing glasses for one reason or another. For example, on days when the child has swimming lessons, contact lenses are more practical than glasses.
ECPs play an important role in selecting the right patients, as well as educating the child and their parents, about the correct ways to use them. I typically see a new contact lens user as often as two or three times a week, to assess how they are adapting to the contact lenses.
As they get used to wearing contact lenses, the visits will become less frequent, tapering to just once a week, and then perhaps once a month or every three months.
Woon Pak Seong is an optometrist and the managing director of Vision Space.
- This is the personal opinion of the writer or publication and does not necessarily represent the views of CodeBlue.
