What amount of axial length growth be expected in myopes versus emmetropes, and how can you tell if your myopia control treatment is working? This important clinical reference provides all this information and more on axial growth in younger and older children, emmetropes and myopes, and even data on typical myopia stabilization.
Myopia control is vital for children with fast myopia progression. What are the key risk factors for faster myopia progression? What clinical findings indicate a more proactive myopia management strategy may be required? This case describes risk factors and evidence-based treatment options for fast myopia progressors.
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.
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.
Young adults wearing the spectacle-mounted Clouclip device to measure viewing behaviour and light exposure also kept an activity diary. Mean daily near work and outdoor time were subjectively reported at about 150% of the objectively measured hours. This indicates the value of objective measures in research, as well as for clinical education and behaviour modification tools in future.
This study measured central and relative peripheral refraction (RPR) in children aged 6-7 years and 12-13 years at baseline and again one year later. There was no correlation found between central and peripheral refraction in the younger group. In the older group, more hyperopic temporal RPR was correlated with a myopic shift, but only explained 10% of the variance in refraction after 12 months.
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.
A country-wide intervention to increase outdoor time in 5-6 year olds resulted in the prevalence of myopia decreasing from 15% in the 2014 cohort (before the intervention) to 8% in 2016 cohort (exposed to the intervention for up to two years) and was stable for three years thereafter. Increasing outdoor time works!