What is myopia control?

Myopia, or short-sightedness, is becoming increasingly common with each generation. In the UK, the prevalence of myopia has doubled in the last 50 years. Typically, myopia starts between the ages of 7 years to 14 years and then progresses for a few years. As a general rule, the later that myopia starts the less it is likely to progress. If it starts as young as at 5 or 6 years, then it is likely to progress to be a high degree of myopia. Myopia is often classified as follows:

· Low (physiological): up to -3.00D

· Intermediate: -3.00D to -5.00D

· High (pathological): over -5.00D

One of the most common activities of eyecare practitioners is to correct myopia with glasses, contact lenses, or laser surgery. A few optometrists have a special interest in myopia control. This involves controlling (reducing) the rate of progression of myopia. At the moment, this means adopting strategies to slow down myopia progression. In the future it is hoped optometrists may be able to reverse myopia and maybe even cure myopia.

We were one of the first practices in the country to offer myopia control. Professor Evans has lectured on this topic and wrote this summary of recent thinking on myopia control as a guide for patients and as an outline of the methods of myopia control which are available at Cole Martin Tregaskis Optometrists.

Why worry about myopia?

Myopia is easy to correct with spectacles or contact lenses, so why bother trying to control myopia progression? Low degrees of myopia are not a major problem, and indeed when people reach their 40s and the eyes lose their ability to focus close to, there are advantages to having a low degree of myopia. But intermediate and high degrees of myopia cause people to be visually impaired without their glasses. For example, a high myope may not be able to see the alarm clock when they wake in the night. For high myopia, glasses will be thicker and less attractive, although modern high index spectacle lenses can make glasses thinner than used to be case and contact lenses are another option. More importantly, high myopia is associated with an increased risk of significant eye diseases, such as retinal detachment, glaucoma, and myopic macular degeneration. If myopia control slows the progression of myopia in a child, this might mean that they only ended up with an intermediate degree of myopia, say -4.00D, instead of a high degree, say -6.00D. This would reduce the risk of eye disease in later life and improve quality of life.

What are the risk factors for myopia?

There is a genetic component to myopia, and this partly explains why in some Asian countries (e.g., Singapore) up to 80% of young people have myopia. If one or both parents are myopic then this increases the risk of a child being myopic. For example, in one study children with two myopic parents were over six times more likely to become myopic than children when neither parent is myopic.

If you would like to assess your child’s risk of developing myopia there is a very good free online calculator at www.myopia.care

Environmental factors have also been linked with myopia, and many people have wondered whether part of the reason for the high prevalence of myopia in countries like Taiwan may be linked to intensive studying from a very young age. In particular, experts have wondered whether the eyes constantly focussing close to on books may be a trigger for myopia. The evidence suggests that this is not the sole cause of myopia, but may be a contributory factor in some cases. Encouraging children to keep their reading at least 30 cm from their eyes, taking breaks from near vision every 30 minutes, and spending school breaks outdoors all have a slight effect at reducing the risk of myopia progression. However, these strategies are not usually effecting at stopping myopia from progressing.

Peripheral defocus and new developments in myopia control

Recent research has highlighted an important factor associated with myopia development. The central area of the retina (fovea or macular) gives us sharpest vision and traditionally the emphasis has been on how sharply spectacles and contact lenses focus an image on the fovea. But recent research indicates that the way in which light is focussed in the peripheral retina may be very important for myopia control.

For children who are becoming myopic, it seems that the peripheral image focus is behind the retina, and this might trigger the eye to grow, which leads to myopia progressing. There are now three options available in the UK to correct this peripheral defocus. The latest development is a new type of spectacle lens, called MiyoSmart. Cole Martin Tregaskis Optometrists are one of the first practices in the UK to use this lens. The other two approaches both use contact lenses: dual focus lenses and orthokeratology.

MiyoSmart spectacle lenses

Professor Evans became aware of research on this lens when it was presented a couple of years ago and we have been eagerly awaiting the arrival of this lens. We were delighted when, in early 2021, we were selected as one of the first practices in the UK to use this product. MiyoSmart can be fitted to normal spectacle frames and does not require the child to use drops or contact lenses. Therefore, this is likely to be the safest form of myopia control. Research published in the British Journal of Ophthalmology found that this slows myopia progression by between 50-60%. It is therefore the only spectacle lens option that is as powerful at slowing myopia as the contact lens options described below. To watch a video about MiyoSmart, click here.

Dual focus contact lenses

In March 2017 the practice was selected as one of the first in the UK to prescribe MiSight, the first daily disposable soft contact lens specifically designed for myopia control. These soft multifocal contact lenses are worn during the day. They are comfortable and give good vision, so are popular with children. More information can be found about wearing soft contact lenses in the page of our website about contact lenses.

A European study published in 2018 finds an average effect at slowing myopia of 39%. A large and ongoing research study involved fitting this lens to children from several countries, including the UK. The latest results show, after wearing the lenses for 3 years, a slowing of the myopia (compared with a control group) of 59%. The lens is only available through specialist practices and Cole Martin Tregaskis is one of these practices.

Orthokeratology

Orthokeratology, also known as corneal reshaping treatment, involves fitting the eyes with rigid gas permeable contact lenses to be worn overnight. The contact lenses are fitted with great accuracy using a corneal topographer and the lenses are precisely manufactured so as to reshape the cornea overnight. The reshaping of the cornea is temporary, but usually lasts for a day or two. The idea is that the cornea is reshaped in a way that corrects myopia, so as long as the contact lens is worn overnight then no glasses or contact lenses need to be worn during the day. Another area of this website is dedicated to Orthokeratology.

For many years, Orthokeratology practitioners noticed that when myopic children were fitted with Orthokeratology the myopia seemed to progress much less than usual. This is now believed to be because the reshaping of the cornea corrects the peripheral defocus. Research studies indicate that Orthokeratology may reduce myopia progression on average by about 45%.

A word of caution

Three points need to be stressed. First, none of the interventions described here are likely to stop myopia progression, just to slow it down. Second, although the approaches described above on average slow myopia progression by about 50%, these are average results and cannot be guaranteed in an individual case. For some children, the myopia progression may be slowed more than this but for others it may be slowed less, or not at all. Third, in medicine a treatment is only taken as being “proven” when supported by several large research studies of a particular design (randomised controlled trial). These should include prolonged follow-up to make sure that the effect of treatment persists. This is not yet the case for these treatments, although the preliminary results are encouraging and show not only slowing of myopia progression but also slowing of the eyeball growth. This is likely to lead to the children having lower degrees of short-sightedness in adulthood and should reduce the risk of complications of short-sightedness in later life.

How to investigate further

If you would like to predict the likely progression of your child’s myopia, with and without myopia control, then there is an excellent online calculator at

https://www.brienholdenvision.org/translational-research/myopia/myopia-calculator.html

If you would like us to investigate the options for myopia control in your child then please contact the practice and ask for an appointment. We will check the eye health, refractive error, and carry out additional tests to assess factors that are relevant to myopia control (including measurement of near esophoria and accommodative lag). We will then discuss the options for myopia control.

Return to Cole Martin Tregaskis home page.

Updated April 2021