Can previous progression predict future myopia?

Paper title: Annual myopia progression and subsequent 2-year myopia progression in Singaporean children

Authors: Saiko Matsumara (1), Carla Lanca (1), Hla Myint Htoon (1,2), Noel Brennan (3), Chuen-Seng Tan (4), Biten Kathrani (3), Audrey Chia (1,5), Donald Tan (2.5), Charumathi Sabanayagam (1,2,6), Seang-Mei Saw (1,2,4)

1. Singapore Eye Research Institute, Singapore
2. Duke-NUS Medical School, Singapore
3. Johnson & Johnson, Vision Care, Singapore
4. Saw Swee Hock School of Public Health, National University of Singapore, Singapore
5. Singapore National Eye Centre, Singapore
6. Yong Loo Lin School of Medicine, National University of Singapore, and National University Health System, Singapore

Date: Dec 2020

Reference:   Matsumura S, Lanca C, Htoon HM, et al. Annual Myopia Progression and Subsequent 2-Year Myopia Progression in Singaporean Children.Transl Vis Sci Technol. 2020;9(13):12 [Link to open access paper] 

The SCORM study (Singapore Cohort Study of the Risk Factors for Myopia) retrospectively analyzed the association between myopia progression within a year from baseline and progression in subsequent years.

The CLEERE group supplemented the findings of this study by developing models to predict future refractive error using variables including previous myopic progression.¹  They found that although there was a weak correlation between the progression seen in one year and the next, predictive modelling relied more on a child's age, sex and ethnicity rather than refractive error and axial length changes.

This study recruited 618 children aged 7 to 9yrs who had a spherical equivalent (SER) myopia of -0.50D or worse at baseline and were followed for at least 2 annual visits to measure their progression via cycloplegic auto-refraction.  Their parents completed questionnaires to provide information on maternal educational level, if the child used a distance correction and when this was first required, the number of hours spent outside and books read in a week.

The annual progression rate declined with age with the progression rates being -0.88D, -0.68D and -0.48D for years 1,2 and 3 respectively.

Children who were slow progressors in the 1^st year (slower than -0.50D per year) showed the slowest mean progression in the subsequent 2 years (-0.41D per year).

Faster progressors in the 1^st year (faster than -1.25D per year) showed the fastest mean progression in the subsequent 2 years (-0.82D per year).

After adjusting for co-founders, the multiple regression statistics showed that for every 1D increase in year 1 progression, year 2 and year 3 progression rate increased by 0.37D and 0.20D, respectively.  Myopic progression in the 1^st year was the strongest predictor of fast 2-year progression, followed by the baseline spherical equivalent and age of onset of myopia.

The measured myopic progression in year 1 appeared to have higher accuracy for predicting progression in the subsequent 2 years than the baseline SER or the age of myopia onset for Singaporean children aged 7 to 9yrs.  However, it wasn't high enough to be the predominant predictive factor and other variables such as parental myopia, lifestyle and ethnicity are also likely to have an influence.

The CLEERE study found that previous progression had little bearing on future change and although this study did not find a definitive factor for predicting future progression, it was able to show that at least annual visits for monitoring myopia progression are important for children.

• Faster progression may be missed if children are not seen frequently enough
• Progression rates may also be variable, meaning children who may initially appear to be slower progressors in the first year may actually accelerate in the following couple of years and vice-versa.

An individually based approach for managing expected myopic progression should take into account the extent of a child's myopia in the previous year, their initial SER, their age, age at onset of myopia and their parental history of myopia

• This was echoed by the CLEERE study¹ which suggested that the previous history of progression or axal length was largely irrelevant to the decision of when to begin treatment

This study had recruited 618 schoolchildren, with 82.4% being Chinese. Children in Asia have been found to exhibit faster myopia progression than European children² meaning the results cannot be easily applied to non-Chinese children. Future research into subsequent year progression for European children would inform us of ethnicity differences.

The children were aged from 7 to 9yrs old, with a mean age of 8yrs.  This is an age group where faster progression can be expected before it slows between the ages of 9 and 15yrs.² This means the data cannot be extrapolated to older children. Further research with a larger sample size could provide us with a more accurate prediction model

The results showed that initial cumulative progression may have some influence on subsequent-year progression.

• This may mean that only the previous year's progression may be relevant in order to make future predictions
• The full benefit of annual monitoring of myopia needs to be explored in order to establish ideal review intervals to gauge progression, although the International Myopia Institute recommends six-monthly review of myopic children³ to assess treatment suitability as well as treatment effect.

This paper appears to disagree with another recent publication on the predictive ability of prior progression history to identify future progression. You can read about this other paper in The Difficulty In Identifying Fast-Progressing Myopes Based On Prior Progression.

Both this and the other study agree that there is a link between progression history and the subsequently observed myopia progression, but that it's not a strong enough factor on its own to determine whether you have a fast- or slow- progressor in your chair. Parental myopia, outdoor time and near work survey data had a limited impact on progression in both of these studies.

Title: Annual Myopia Progression and Subsequent 2-Year Myopia Progression in Singaporean Children

Authors: Saiko Matsumara, Carla Lanca, Hla Myint Htoon, Noel Brennan, Chuen-Seng Tan, Biten Kathrani, Audrey Chia, Donald Tan, Charumathi Sabanayagam, Seang-Mei Saw

Purpose: To investigate the association between 1-year myopia progression and subsequent 2-year myopia progression amongst myopic children in the Singapore Cohort Study of the Risk Factors for Myopia (SCORM).

Methods: This retrospective analysis included 618 myopic children (329 male), 7 to 9 years of age (mean age, 8.0 ± 0.8) at baseline with at least two annual follow-up visits. Cycloplegic autorefraction was performed at every visit. Receiver operating characteristic (ROC) curves from multiple logistic regressions were derived for future fast 2-year myopia progression

Results: Children with slow progression during the first year (slower than -0.50 diopter [D]/y) had the slowest mean subsequent 2-year myopia progression (-0.41 ± 0.33 D/y), whereas children with fast progression (faster than -1.25 D/y) in year 1 had the fastest mean subsequent 2-year myopia progression (-0.82 ± 0.30 D/y) (P for trend < 0.001). Year 1 myopia progression had the highest area under the curve (AUC) for predicting fast subsequent 2-year myopia progression (AUC = 0.77; 95% confidence interval [CI], 0.73-0.80) compared to baseline spherical equivalent (AUC = 0.70; 95% CI, 0.66-0.74) or age of myopia onset (AUC = 0.66; 95% CI, 0.61-0.70) after adjusting for confounders. Age at baseline alone had an AUC of 0.65 (95% CI, 0.

Conclusions: One-year myopia progression and age at baseline were associated with subsequent 2-year myopia progression in children 7 to 9 years of age.

[Link to open access paper]