How to manage the very young myope

The rates of myopia globally are increasing, and earlier onset of myopia progression is being observed.¹ Earlier onset generally leads to higher levels of final myopia and more eye health risks, so management of the very young myope is of utmost importance.

Most myopia control intervention studies employing spectacles or atropine enrol from age 6, and most contact lens studies enrol from age 8. So how should we manage myopes younger than this?

In this blog we'll give you some guidance on managing myopes under age 6-7 with low and moderate myopia. These are the children for whom we know we should intervene but don't have the research evidence to back our management as we do for the typical myopia control study participant who is aged 8-14 years with myopia of 1 to 5 D.

Measuring visual acuity can be a challenge in these younger children. Children as young as three may be competent of reading a modified chart such as LEA symbols or HOTV with high levels of accuracy.² Retinoscopy in children is very important, as they may be too young to provide accurate subjective refraction, and is the most sensitive test for detecting refractive error in children when done by an eye care professional.³ Read An Ode to my Retinoscope for a deeper understanding for just how dedicated we are to our favourite clinical test for paediatric refraction. Cycloplegic refraction is an important tool, and is considered the gold standard for refractive assessment by the International Myopia Institute where indicated.⁴ 'Where indicated' does not mean you have to undertake cycloplegia to manage myopia - it may not be available in your country, may not be suitable for that child, or may not be needed if ocular accommodation is otherwise controlled. As an eye care professional, you know best when cycloplegia is necessary, and it can be very useful in younger children to ensure refractive accuracy.

There is an established degree of congenital myopia in infant children, reported as 4-6%. These children do have a possibility of natural emmetropisation, with rates of myopia declining to 2% by school age.5 When children are particularly young, such as toddlers around two and three, correction may be important to avoid amblyogenic outcomes if the child doesn’t have clear vision. Undercorrection, although not appropriate for older children as it likely increases myopia progression,6 can be indicated when under age 4 to not interfere with emmetropization.7 Where amblyopia is not a concern in these very young low myopes, it may be appropriate to watch and wait. To see this in action, read this Clinical Case on A two-year-old with low myopia - to correct or not?

These are our key indications for prescribing in younger age groups. In her open access paper To prescribe or not to prescribe? Guidelines for spectacle prescribing in infants and children, Susan Leat wrote that when considering prescribing glasses for a child up to six years of age, the following questions must be considered. For more detail each of these questions, you can read her paper via the link above.⁷

1. Is the refractive error within the normal range for the child's age?
2. Will this particular child's refractive error emmetropize?
3. Will this level of refractive error disrupt normal visual development or functional vision?
4. Will prescribing spectacles improve visual function or functional vision?
5. Will prescribing glasses interfere with the normal process of emmetropization?

Key indications for correction are provided below from Leat's paper, for astigmatism, anisometropia and myopia. For hyperopia (not the subject of this website) you'll have to read the paper!

Consider referral and/or co-management, depending on the scope of practice and appropriate clinical pathways in your country, for the following children:

• Where referral and/or co-management is prudent or required for strabismus, amblyopia or other eye health issues
• Children whose dioptres of myopia exceeds their age in years. These children could be at higher risk of systemic syndromes associated with myopia
• Children under age 6 with high myopia (more than 5-6D). Read more about these latter two types of children in this Clinical Case entitled How to manage the highly myopic toddler.

Spectacles are likely to be our first line solution for vision correction in toddlers and young children. Consider firstly giving them clear vision and perhaps monitoring myopia progression for 6-12 months while educating parents on myopia control interventions.

Spectacle lens interventions like progressive addition lenses (PALs) and bifocals are likely to be best tolerated in this group, although they've only been studied from age 6-8. Read more about which to prescribe in When to prescribe spectacles for myopia control.

Atropine eye drops have been studied on children as young as four in the context of myopia control, and new studies employing commercially prepared, stable formulations are recruiting down to age 3. Read more about these in our blog The Latest and Greatest Research on Atropine.

For parents, atropine may seem a simple and appealing treatment, provided compliance can be achieved. Keep in mind management of the potential side effects of large pupils and reduced accommodation response, which can be managed with the appropriate spectacles. Read more on this in our blog When to prescribe atropine for myopia control.

Contact lens fitting - whether soft multifocal contact lenses (MFCL) or orthokeratology (OK) - is a challenge in the toddler and preschool aged population. Fitting infants and younger children with contact lenses is not unheard of, for example in cases of congenital cataract post-surgery. However CL fitting in a child under age 6-7 for myopia control may not have the same risk-to-benefit picture as what we may consider more medically necessary CL fitting to avoid amblyopia; and has no research evidence base. Most MFCL and OK studies focus on the 8-14 year old population, and whilst some include younger children, none include children under 7. Recent paediatric contact lens prescribing surveys have shown that while CL prescribing for myopia control is skewed towards a younger age than non-myopia control fits, the median age is 13 years and less than 5% appears to take place in children under 8 years of age.⁸

Another paediatric CL prescribing survey showed that whilst 11% of CL fits took place for children under 10,⁹ only 0.1% were for infants and 1.6% for children aged 6-12. Studies that look at feasibility of CL and adverse events related to contact lens wear tend to include youngest age at 8.¹⁰

This is not neccessarily because CL's are less safe in younger children; it's more likely due to patient, parent and practitioner factors. Bullimore examined soft CL safety in children down to age 7 and found that the risk of adverse events in children to age 12 appeared to be lower than in teens and adults, likely due to close parental supervision of younger CL wearers.¹⁰ OK has also shown a good safety profile in children - read more about both in our blog Contact lens safety in kids.

Parents who have prior experience with contact lens wear themselves; and younger kids with the maturity and willingness to cope with CL handling are likely to present the best candidates. It can also be helpful if older siblings wear CLs. Clinically, we have fit children from age 6 with contact lenses for myopia control provided these conditions are met. In many cases, parents may commence putting CLs on and off and undertaking cleaning, with the child taking an increasing role as their confidence builds.

This is important for any myope. Discuss our key goals of increasing outdoor time to around 2 hours a day on average; and managing near work and screen time. The Australian Department of Health and the American Academy of Paediatrics recommend that children under two years of age should have no screen time, and children aged 2-5 years should have a maximum of one hour a day of screen time.

Key resources for parents on our website MyKidsVision.org are as follows.

• Close Work and Screen Time in Kids (blog)
• How Much Time Should My Child Spend Outdoors? (blog)
• Three simple close work and outdoor time habits to promote healthy development in children (How-To video guide)

The lack of myopia control evidence in children under age 6-7 years doesn't mean it won't work - it's more likely a reflection of what ethics committees permit in research studies, and the risk-to-benefit-to-hassle consideration in including younger children in research or prescribing them particular interventions.

Myopia can onset and progress before this age, and earlier onset means faster progression and a greater risk of high myopia, so doing something is better than nothing. Of crucial importance in this age group is ensuring clear vision and avoiding risk of strabismus and/or amblyopia. Consider refractive correction first and myopia control next - starting with explaining to parents the long road ahead for myopia management, and what this could include.

What you prescribe will depend on the child's individual presentation, parental preference, the child and family's compliance ability - as it does for any myope. Our very little myopes, though, need special attention to ensure they enjoy clear vision now and the best chance of lower lifelong myopia.

• How to achieve accurate refractions for children

• Case study: A two-year-old with low myopia - to correct or not?

• Case study: How to manage the highly myopic toddler