Authors Sarah L Morgan BSc (Hons), MCOptom, MPhil, FAAO, FBCLA

Reference Age six – the refraction milestone? By Sarah Morgan BSc (Hons), MCOptom, MPhil, FAAO, FBCLA. Originally published in Optometry Today, 08 August 2020

Introduction

In 2015, the World Health Organisation (WHO) placed myopia on the world health agenda.1 One of the chief concerns, is the future burden both to the patient and also the economic health costs of myopia related pathologies such as myopic macular degeneration.   From an epidemiological standpoint, the prevalence of myopia has been growing rapidly around the world, and for patients in their late teens, over 90% in East Asia and 31% in Australia have myopia.1  Whilst the prevalence of myopia in UK white children is lower than in East Asian countries where most children leaving school are myopic, almost one in five teenagers in the UK is myopic and this is predicted to increase.2  Given that the age of onset of myopia typically occurs between age 6 and 14 years of age, this article proposes that a full optometric examination at age six is the best opportunity to assess the individual risk of future myopia – in advance of the onset.

Background

It is common sense that a child with undiagnosed (and correctable) poor vision should be identified, so they do not miss out educationally or suffer detrimental effects to their social development with potentially long-lasting effects into adulthood such as reducing their career opportunities.3  Whilst vision screening may be offered to some pre-school children, even for those that are screened, refractive status is not typically included in screening assessments.4  Once a child has started school, an ad-hoc ‘examine whenever complaints occur’ is generally the current approach.5  This reactive approach not only risks myopic children going undetected ‘until they complain’ (or perhaps someone else notices they have a vision problem), it also leaves a percentage of children with amblyopia undiagnosed (if a strabismus has been missed, or their reduced vision in one eye was not picked up during screening) putting the child at threat of partial sight, or worse, if they later lose their functioning eye from trauma and/or pathological cause.  The benefits of a comprehensive eye examination at this key refractive milestone at age six should not be underestimated by optometrists and parents.6

ClassroomA classroom scene through the eyes of an uncorrected myopic child

Current practice

When seeing children for eye examinations, there appears to be no firm ‘call to action’ given to parents when compared with other key milestones in the growth stages of a child, e.g. height and weight tracking of children, immunisations, dental checks.7-9  Most parents assume that their children’s eyes have been checked via other healthcare professionals,10 perhaps by a paediatrician at birth, a health visitor, school vision screening and during visits to the family doctor – a tacit ‘someone will let me know if there is anything wrong’.  Of course, these healthcare professionals are unlikely to be experts in the eye and vision and it is doubtful that they will have checked the  refractive status of the child (they are rarely familiar with refractive status norms).

A school age child is typically brought for a comprehensive eye examination if something or someone has caused the parent to react:

  • child complains of blurry vision/ can’t see
  • child complains of tired eyes
  • parent has concerns that their child may have a vision problem
  • school screening test has recommended an eye examination
  • child tried a friend’s spectacles on and said they could see better
  • child’s teacher has some concerns about vision / educational progress
  • parent’s optometrist has recommended to bring the child in to be examined

Given the above, taking a child for a routine eye examination is not on the checklist for the majority of parents, and not even those for whom it should or could be such as, parents with a history of squint / amblyopia / significant refractive error).10  Parents respond well to key milestone advice,10 the simplicity of which helps to cut through the busy, daily lives of parents and brings into sharp focus key healthcare checks.  It is interesting to note that dental information discusses the consequences of tooth decay in terms of number of school days missed due to pain and treatment, so there is a glaring opportunity for optometry to provide information on the countless hours of lessons ‘missed’ simply by not being able to see in the classroom; a similar argument can be made for extracurricular activities such as sport or music.

Six is the magic number
It is hoped that the majority of children in the amblyopia/high refractive error group will have been identified in earlier checks, but the silent onset of myopia is not on the radar.  Myopia is insidious in its onset, often going unnoticed until the child or someone else notices there may be a vision problem, and optometry is well-positioned to identify those children at risk ahead of the onset.

Reliability of refractive error at age six
Refractive error can change dramatically over the first five years of life, so the results determined around age six more clearly inform the future vision correction needs of the child.6  Beyond a small subset (5-10%) of the paediatric population with known risk factors,5 examinations for the majority occur by ‘chance’ rather than a scheduled ocular health initiative.  However, for children who have not been examined before six years of age, this represents the best ‘fall back’ time to refractively assess children.  The refractive status at this age is the best single predictor of the risk of a child developing myopia in their teens or sooner,6 and examining children at this key milestone along with a careful explanation of the findings and likely future changes and examination intervals represents a very useful guide for parents.  Zadnik et al state that ‘Children examined in Year 1 (age 6 years) with less than +0.75D of hyperopia are at increased risk for developing myopia. This predictive model should enable clinicians and scientists to evaluate the risk for myopia in a child using simple, feasible measures’.  Further to this, research has shown that age of myopia onset is a predictor for high myopia in later childhood.11

Letter recognition
Once a child starts school, one key focus is learning to read.  Whilst letter recognition is not an essential component of visual acuity measurement in a child, research has shown that this is much improved by age six (Year 1 children) compared with children who are in their first year of school (Reception).12  This difference (seeing a child at age six versus age five) provides the optometrist with more confidence in their subjective evaluation, as well as giving clear evidence of visual difficulties to the parent attending the examination with their child; this latter point is commonly under-appreciated.

Children learning their letters in school

Opportunity to communicate and educate
Eye care professionals are extremely familiar with myopia, and this is perhaps the greatest distinction between them and the parents of the newly diagnosed myopic child – context.  Parents rarely know what myopia is, so are even less likely to be aware of the way in which myopia typically progresses.  Additionally, where one lay person may have some sense of refractive error running in families, another will not have made any connection.13

In a survey of myopic parents with children aged 8-15 years, nearly 50% had not considered that their child could also become myopic.13  It is vital that optometrists appreciate this huge educational gulf between their knowledge and that of the parent (and child).  Parents deserve to be carefully informed and educated both when a child requires a refractive correction or when such a correction is likely to be required in the near future.  Such conversations are not straightforward and are made much easier if the possibility of a need for refractive correction has been predicted at an earlier examination.  If no such forecast has been made previously – as in the case of a ‘reactive’ approach to optometric care for school age children – the parental discussion is generally one of explaining ‘bad news’.  Many parents see a need for vision correction as disadvantageous for their child.  There are several pieces of ‘bad news’ the optometrist must deliver, along with some negative responses:

Bad news

  1. your child cannot see as well as they once did
  2. your child has myopia
  3. your child needs to wear glasses to see clearly (e.g. in the classroom)
  4. your child will need to be examined again soon (a further visit)
  5. your child will likely need a stronger prescription next time
  6. your child’s myopia will continue to worsen as they grow
  7. your child will be dependent on vision correction for the rest of their life
  8. (probably unsaid) your child is at increased risk of myopic pathology with age

Negative responses

  1. parents may feel ‘guilty’ that they did not notice the vision problem sooner
  2. parents may not ‘trust’ the outcome of the examination (even if the child most definitely is myopic and requires spectacles) – especially if the parent has not noticed the child has a problem / the child has no complaints (e.g. only a teacher concern)
  3. subsequent examinations typically require ‘stronger’ prescriptions, which, if not carefully discussed ahead of time, can cause parents to worry that wearing the spectacles is making their child’s eyes worse

Prescribing for the first time for a child with myopia is not uncommon for the optometrist, but it is often a ‘first’ for the parent (and certainly for the child).  It is worth considering how different this could be had the child attended for a previous eye examination.  Such a child might show low levels of hyperopia, the best single predictor of their individual future risk of myopia.6  At this visit, the optometrist would have the opportunity to discuss what is then only a ‘possibility’ of their child becoming myopic – no prescription for spectacles would be necessary on that first occasion.  Effectively, the news at the first examination is largely positive for the time being, with the only ‘prescription’ being advising the parents to encourage their child to spend more time outdoors.

The parent (and child) can be counselled on signs that relate to increasing myopia, and what ‘everyday tests’ the parent and child can watch out for (e.g. subtitles on the television at a certain distance, the digital clock on a kitchen appliance).  Discussions can be had with members of the family to consider if this is something that might be familial in origin, and of course, other siblings and relatives can be considered (and examined).  There is also the opportunity to mention future possibilities such as myopia management options, such as contact lenses.  All of these points are much easier to discuss, and much easier for the parent to listen to and process, at a time when there is not abject panic that a child now needs spectacles along with the parental guilt of wondering for how long their child has been suffering from poor vision.  The outcome of the initial examination at age six also informs both the optometrist and the parents about the recommended schedule for future examinations.

Parents can be educated on signs their child could be myopic

Conclusions

One of the primary objectives of an eye care professional is to correct refractive error in order that a child can attain the best visual acuity possible.  Having the opportunity to examine a child who may be at risk of uncorrected refractive error is key, and a clear message to parents of when, by whom and where to have their child seen is vital.  The current approach is ‘open’ at best, and moving ‘an eye examination at age six’ to the ‘must do’ list of key milestones in the child’s developmental healthcare plan is a great opportunity to put optometric care and management on the parental checklist.

A child at risk of developing myopia, if seen at this key ocular milestone, provides a valuable moment in time for both the child and the parents.  An initial examination where no action is required, is a positive experience all round.  This places the optometrist in a good position to counsel both the child and the parent(s) on the future possibility of a change in vision, dependent on how their eyes grow as the child grows, and allows them all to be on the lookout for visual changes.  Just as examining a pre-presbyope gives the optometrist the opportunity to discuss presbyopia and forewarn the patient about these impending changes, a child at known risk of myopia can also be pre-handled in this way promoting a trusted relationship for the years ahead.  Should the child fulfil these statistically predictable changes, not only will the parent (and possibly even the child) have witnessed first-hand the changes over time, they are able to bring the child to see the optometrist at the earliest opportunity, so the first prescription can be given and further conversations around the future management of the progression of the myopia discussed.  No parent wants their child to miss out, but without proactive advice and direction, they remain ignorant.  Children deserve the opportunity to ‘see the best they can see’ so that they can ‘be the best they can be’ during their early years education right through to high school and beyond.

Sarah Morgan is an optometrist and staff development consultant. At The University of Manchester, she lectures and leads clinical sessions where she holds the post of Vision Sciences Fellow.

This article was supported by a grant from CooperVision.

References

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