Myopia Measurement
Using Refractive Error to Identify Pre-Myopia in Children

Identifying children at risk of developing myopia can be done by evaluating risk factors such as family history of myopia, refractive error, lifestyle, certain vision disorders, and age of onset.

Myopia can be predicted before onset in young children. This Myopia Moment provides a brief overview of how to use refractive error to evaluate pre-myopia in a child.

CLINICAL BACKGROUND

Children can be at risk of developing myopia even if they present with minimal refractive error, including emmetropia or less hyperopia than expected for their age.
What is considered normal refractive error expected for a child’s age can be influenced by ethnicity.

SITUATION GLOBALLY

Population-based data on what is accepted as “normal” development of refractive status in children is not available for many parts of the world and across ethnicities.

WHAT CAN YOU DO?

Develop an understanding of the normal refractive development of the population you serve in your community.
Use your own insight and clinical experience, in conjunction with evidence from well designed studies, to evaluate whether a child is less hyperopic than he or she should be at appropriate age milestones.

Who’s more at risk of developing myopia?

+0.50 D Age 6

+1.25 D Age 6

GENERALISED DATA

International Myopia Institute: Pre-myopia is defined as a refractive state of an eye of < +0.75 D and > -0.50 D in children where a combination of baseline refraction, age, and other quantifiable risk factors provide a sufficient likelihood of the future development of myopia to merit preventative interventions.

IMPORTANT

Using a baseline refraction to define a child as pre-myopic is helpful but should be considered in conjunction with other risk factors that may be present.

Risk factors (modifiable):

<2 hours of outdoor time per day
Significant time spent on near work, such as use of digital devices.

Risk factors (non-modifiable):

Age: younger age of onset
Family history: myopic parent(s) and ethnicity
Other vision disorders

Remember that a child may pass a vision screening and still be at risk of developing myopia.

Children should be seen for a full eye examination early, prior to beginning school, and regularly to monitor refractive status and assess overall risk for myopia.

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Prepared by the World Council of Optometry Myopia Management Resource Committee 2021. The World Council of Optometry Myopia Management Standard of Care initiative is supported by a grant from CooperVision.

Flitcroft et al. IMI – Defining and Classifying Myopia: A Proposed Set of Standards for Clinical and Epidemiologic Studies. Invest Ophthal Vis Sci. 2019
Jones-Jordan LA et al. Early childhood refractive error and parental history of myopia as predictors of myopia. Invest Ophthalmol Vis Sci. 2010.
Mutti DO et al. Refractive error, axial length, and relative peripheral refractive error before and after the onset of myopia. Invest Ophthalmol Vis Sci. 2007.
McCullough S et al. Axial growth and refractive change in white European children and young adults: predictive factors for myopia. Scientific Reports. 2020.
Zadnik, K et al. Prediction of Juvenile-Onset Myopia. JAMA Ophthalmol. 2015.