A study of myopia progression in France

Paper title: Progression of myopia in children and teenagers: a nationwide longitudinal study

Authors: Dorian Tricard (1), Simon Marillet (1), Pierre Ingrand (2), Mark A. Bullimore (3), Rupert R.A. Bourne (4), Nicolas Leveziel (1,2,5,6)

1. Ophthalmology, CHU Poitiers, Poitiers, France
2. University of Poitiers, Poitiers, Poitou-Charentes, France
3. University of Houston College of Optometry, Houston, Texas, USA
4. Vision & Eye Research Unit, Anglia Ruskin University, Cambridge, UK
5. INSERM CIC 1402, Poitiers, France
6. INSERM 1084, Poitiers, France

Date: Mar 2021

Reference:  Tricard D, Marillet S, Ingrand P, Bullimore MA, Bourne RRA, Leveziel N. Progression of myopia in children and teenagers: a nationwide longitudinal study. Br J Ophthalmol. 2021 Mar 12: bjophthalmol-2020-318256.

[Link to open access paper] 

This nationwide prospective cohort study investigated myopia progression in French children and teenagers aged between 4 and 17yrs, over a 6yr period.  Myopic progression during follow-up periods was examined in terms of their age, gender and strength of their first optical correction.

From the data of 136,333 children and teens, 86,604 were classed as progressors. Factors found to be associated with faster progression were:

Age

• Myopia was found to progress linearly within separate age group stages, but to be non-linear overall as age increased.
• Children aged 7-9yrs and 10-12yrs experienced -0.43D and -0.42D changes respectively after an 11-24mth period
• The rate of progression was found to be slower for children older and younger than this.

Refraction

• Initial refractions of -1.00D or stronger had a progression rate of -0.33D or more, compared to an average of -0.23D for those with less myopia
• However, irrespective of the baseline myopia, the 7-9yr group showed the fastest progression
• It was also found that if children had a correction of -4.00D or stronger at age 9yrs, their progression rate was likely to increase by approx. -1.6D after a further 4-5yrs irrespective of the initial refraction
• The risk of developing high myopia before a 5.5yr follow up period was calculated as being 58% for an SE of -4.00D to -6.00D, compared to 16% for -3.00D to -4.00D powers.

Gender

• Girls were seen to have more progression than boys (-0.35D and -0.32D respectively).
• This difference was wider at the 6.5yr follow up period (-1.42D compared to -1.24D)

Children with higher myopia, girls and those aged between 7 and 10yrs old experienced more change in their myopia and were at increased risk of higher myopia within 5yrs of their first correction.

Further research is needed into why myopia progression may be slightly faster in girls and the reason for slower progression in younger children.

Children aged between 7 to 10yrs were shown to be fast progressors regardless of their baseline myopic refraction. This makes this age group candidates for myopia management interventions in practice, especially if they are girls.

Eye Care practitioners can also pre-empt lifestyle advice for parents of children younger than 7yrs, knowing that progression will likely be fastest from this age.

This study was able to confirm gender differences in progression found from other studies and other countries. Further research can discover if the reason for this disparity is due to lifestyle differences between girls and boys (varying close work and outdoor time).

Future studies could also investigate if myopia onset and slower progression in pre-school aged children (under age 7) has a different underlying cause to that of school-aged children.

Title: Progression of myopia in children and teenagers: a nationwide longitudinal study

Authors: Dorian Tricard, Simon Marillet, Pierre Ingrand, Mark A. Bullimore, Rupert R.A. Bourne, Nicolas Leveziel

Purpose: Data on myopia prevalence and progression in European children are sparse. The aim of this work was to evaluate the progression of myopia in children and teenagers in a large prospective study.

Methods:  A prospective study involving a nationwide cohort. Myopia was defined as a spherical equivalent (SE) of ≤ -0.50 diopters (D). Data on refractive error, gender and age were collected in 696 optical centres in France between 2013 and 2019, including 136 333 children (4-17 years old) in the analysis. Progression of myopia was assessed between the first visit and the last visit over up to 6.5 years.

Results: Mean age was 11.3±3.8 years (55.0% of female). The proportion of children progressing more than -0.50 D per year was higher in age groups 7-9 years and 10-12 years and in children with SE ≤ -4.00 D at first visit, representing 33.1%, 29.4% and 30.0% of these groups, respectively. In multivariate analysis, progression during the first 11-24 months was higher in the 7-9 and 10-12 age groups (-0.43 D and -0.42 D, respectively), for higher SE at baseline (at least -0.33 D for SE ≤ -1 D) and for girls (-0.35 D).

Conclusions: This is the first French epidemiological study to investigate myopia progression in a large-scale cohort of children. Sex, age groups and myopia severity are associated with differing rates of progression.

[Link to open access paper]