Science

Myopia progression

Lifestyle changes for Chinese school children during COVID-19 home confinement

A vision-screening program was able to provide data before and after Chinese schoolchildren were confined to home learning during the COVID-19 pandemic. Overall, more hours were spent indoors and less time was spent outdoors during this time, across all age groups. The younger schoolchildren had increased incidence of myopia and faster progression, whereas an increase in the prevalence of high myopia was found in the older children.

Can myopia calculators accurately predict children’s myopia progression?

This study investigated the accuracy of the Brien Holden Vision Institute (BHVI) myopia calculator in predicting myopia progression. The extent of myopia progression over 1-2 years in children corrected with single vision spectacles was accurately predicted by the BHVI myopia calculator in 32-38% of 7-13 year old Hong Kong children. Around one-third progressed more and one-third progressed less than the range predicted by the calculator.

The LAMP Study data over three years: 0.05% atropine leads and minimally rebounds

The Low-Concentration Atropine for Myopia Progression (LAMP) Study has provided invaluable data on comparisons between 0.05%, 0.025% and 0.01% atropine treatment. The three year data has shown 0.05% to be most effective for continued treatment, while children discontinued showed a small, ‘clinically insignificant’ rebound effect. Learn more about the one, two and three year LAMP data here.

Increased myopia during the COVID-19 pandemic

Children aged 6 to 8 years old in China were found to experience a mean -0.30D myopic shift and a significant increase in myopia prevalence during a 5-month long COVID-19 home confinement period. Due to their age and corresponding critical stage in visual development, the change in the children’s environment and lifestyle may have been more responsible for their increased myopia than the increased online learning.

Does myopia occur earlier in children if their parents are myopic?

This multi-ethnic study found that parental myopia was a risk factor for myopia development in pre-school age children. The age the parents became myopic themselves had a dose-dependent effect in their children if both parents had onset of myopia before age 12. Eye care practitioners can use this to identify which children may benefit from early myopia treatment intervention.

What is the effect of uncorrecting, undercorrecting and overcorrecting myopia in children?

This systematic review of 9 studies confirms that under-correction of myopia does not slow progression; rather, at least half of the studies have shown the myopia progression is accelerated. There was no benefit found in overcorrection, and the evidence for un-correction was equivocal. Clinically, this advocates for the full correction of myopia.

Exploring the limits of myopia control efficacy

Considering even emmetropic eyes elongate, what are the limits of myopia control efficacy? This novel analysis explores the absolute axial elongation of treated and untreated myopes in the MiSight 3-year clinical trial in comparison to previously published models of myopic and emmetropic eye growth. The results indicate a potential limit to the short-term percentage efficacy of myopia control treatments.

Learning more about ‘normal’ axial elongation in emmetropic children

Previous multi-ethnicity studies have shown ‘normal’ axial elongation in emmetropic children to be around 0.1mm / year. In this study, 700 Chinese schoolchildren with stable emmetropia showed 0.2mm per year axial elongation from age 7-11, which reduced with age and ceased at age 15. This appears higher than measured in Singaporean Chinese children in the SCORM study, 20 years ago.

Is there ‘physiologic’ eye growth in myopia progression?

It’s known that emmetropizing children undergo axial eye growth of around 0.1mm per year. Is this amount of growth in myopes also ‘physiologic’? In this study, data from six myopia control clinical trials was analyzed to find the axial growth component which did not result in a change in refraction. For myopes, this ‘physiologic’ growth appears to be less than 0.1mm per year, which has implications for judging progression and treatment success.

Which children are at risk of developing high myopia in their teenage years?

A combination of higher baseline myopia, parental myopia and faster 3-year progression in earlier childhood were strongly predictive of teenage high myopia in this study. Young patients with these combination of factors should receive closer clinical monitoring and timely interventions to slow myopia progression.