Should we start myopia control for an asymptomatic low myope?

How should a young asymptomatic low myope be managed? Should you monitor with no correction due to lack of symptoms, or start myopia control from the first indication of myopia? The case discussion is as follows.

Binocular vision can play an important role in myopia onset and progression. Read more in our blog Four reasons why binocular vision matters in myopia management. Managing any potential binocular vision issues is in the patient’s best interest to ensure a comfortable, robust visual system.

The clinical findings indicate an accommodative lead and difficulty in accommodating through a -2D lens. This suggests a potential issue in the child’s accommodative system. Since childhood accommodation can influence refractive error results, an accurate refraction is required to confirm the low myopia. Read more about techniques, when to use cycloplegia and alternative options in How to achieve accurate refractions for children.

There has been a school of thought suggesting that under-correcting myopia in children may reduce myopic progression, and indeed even in the current day around 20% of eye care practitioners still believe this. This has been disproven: under-correction of 0.75D (blurring the child’s vision to 6/12 or 20/40) has been shown to speed up myopic progression and axial elongation.¹

However, Sun et al found that myopic progression and axial length elongation occurred at a lower rate in a group of children who were uncorrected for their myopia compared to their fully corrected counterparts.²

A systematic review published in 2020 found that there was overall no benefit to under-correcting myopic children, and their full correction should be prescribed. The review also highlighted the difficulties in fully evaluating the effect of under-correction, given that children will often experience this in between eye exams due to myopia progression.³

What should you do? Use your clinical judgement. Even if a child has no symptoms, their unaided acuity and binocular vision function may not be normal, and need correction.

1. If the child has good unaided acuity and normal unaided binocular vision function, you could potentially review them again in six months. Six monthly reviews are recommended for myopia management by the IMI Clinical Management Guidelines.
2. If the child has reduced unaided acuity they need vision correction. At that point you can then consider using a myopia correction which also provides myopia control - myopia controlling spectacle or contact lenses, or atropine as a first line treatment with spectacles.

We don't know the child's unaided acuity in this case. Clinically, it does appear that 6/12 or 20/40 unaided vision is the clear line in the sand where optical correction is necessary, to avoid under-correction and also ensure a child can function normally, given the World Health Organization defines this as 'mild vision impairment'.

The first consideration would be to assess the child’s risk factors for myopia progression, and she has three that indicate significant risk for progression, indicating the imperative for early intervention with a myopia control strategy.

1. Her age - particularly being under age 9 at myopia onset⁴
2. Both parents are myopic⁵
3. South East Asian ethnicity.⁶

Ethnicity is important because Asian ethnicity is a key risk factor for myopia onset and progression, compared to other ethnicities, regardless of country of residence. Each of these three risk factors – age, parental myopia and ethnicity – are of course not modifiable, but important to identify as a myopia managing practitioner. You may choose not to discuss ethnicity as a risk factor with parents, where there may be sensitivity or it may not seem helpful, but even so it is worth keeping in mind clinically to help drive a proactive treatment strategy.

The commenters mostly suggest prescribing myopia controlling spectacle or contact lenses. As the patient may have some accommodative issues, she could potentially benefit from spectacle lenses with a near addition while doing near work. Atropine was also initially suggested, with consideration given to possible side effects - any impact on accommodation or pupil size can be managed with progressive addition or bifocal spectacle lenses, with or without photochromatic treatment.⁸

As for all myopes, It is also important to emphasize the importance of managing near work and outdoor time in for both delaying myopia onset and reducing risk of progression. The key ‘rules’ to provide to parents are:

• The outdoor rule: Spend at least 90 minutes a day outdoors, on average
• The two hour rule: Try to limit leisure screen and near work time, after school, to less than two hours a day
• The elbow rule: Keep a forearm (hand-to-elbow) distance between books or screens and the eyes
• The 20/20 rule: Every 20 minutes take a break for 20 seconds and look across the room

For more help with the main messages on visual environment, read Keys to communication in myopia management.

Read the latest science on these visual environment topics in our exploration of the following key meta-analysis papers.

• The association between near work activities and myopia in children
• The association between digital screen time and myopia
• How outdoor time influences myopia prevention and control

1. Myopia management can be implemented from the early stages when a child is pre-myopic or in the early stages of myopia. It is important to evaluate the child's visual function in cases of low myopia, and risk factors for myopia progression in determining the strategy to discuss with parents.
2. Whether optical correction and/or myopia control is prescribed or not, asking questions and providing advice on near work and outdoor time habits is important.