The Northern Ireland Childhood Errors of Refraction (NICER) study on myopia

MEMBER BRIEFING

Background

The Northern Ireland Childhood Errors of Refraction (NICER) study, part funded by the College of Optometrists, is the largest ever in the UK to examine changes in children’s vision and cycloplegic refractive error over time. Since 2006, the College has funded researchers at Ulster University to undertake a longitudinal study of refractive error, ocular biometry and visual status. The latest findings from this ongoing study provide vital information on how children’s eyes grow and change in the 21st century and inform how the profession’s practice and advice might change in view of these findings.

Key findings on myopia 

Prevalence 

  • Nearly one in five teenagers in the UK is myopic1,2. 
  • Myopia is more than twice as prevalent among UK children now than in the 1960s: 16.4% vs 7.2%3,9. 
  • The prevalence of myopia in white children in the UK is similar to white children in other countries1,4,5. 
  • The prevalence of myopia in white children in the UK is much lower than in Asian countries where the majority of school leavers are myopic. For example, in South Korea, 96.5% of 19 year old males are myopic6. 

Onset and progression 

  • Myopia is most likely to occur between six and 13 years of age9. 
  • Children are becoming myopic at a younger age in the UK9 than in Australia5. However, at ages 18-19 years, the prevalence of myopia in Australia and the UK is similar9. 
  • Between the ages of six and 13 years, children become more myopic by, on average, -0.23D per year, as compared to an average change in myopia of -0.10D per year between the ages of 12 to 20 years9.

How did we do it?

Evidence from all over the world suggests that myopia is increasing in prevalence. The NICER study is the first study in the UK to use cycloplegic refraction to describe the prevalence, onset and progression of myopia in children. 

The information gathered will allow the profession to advise parents and young people about myopia, support the development of targeted interventions for myopia, and inform policy on sight test intervals in childhood. 

What did the NICER study researchers do?

Researchers recruited a representative sample of 1,068 children in Northern Ireland at 6-7 years (cohort 1) and 12-13 years (cohort 2) and tested them three times over a period of six years. Ninety nine per cent of children recruited were white, which is consistent with the population of Northern Ireland. It is known from other studies that ethnicity affects myopia prevalence. Therefore, the NICER findings are most applicable to white children. The NICER researchers measured: 

  • monocular distance acuities 
  • cover test (distance and near) 
  • cycloplegic refractive error of each eye 
  • ocular biometry.
Evidence from all over the world suggests that myopia is increasing in prevalence

How might the research affect you in practice?

  • Optometrists should use their professional judgement to determine the most appropriate intervals for sight testing patients, depending on their clinical needs10. To ensure refractive error is optimally corrected, it may be appropriate to examine children who are myopic, or at risk for myopia, annually until the age of 12-13 years, and every two years thereafter. 
  • Parents who are myopic should be told to expect myopia in their children and ensure they get their children’s eyes tested regularly in the early years of primary school. 
  • The current evidence base suggests that the length of time spent on near vision tasks (for example, studying or screen time) does not have a strong influence on myopia development. However, an active lifestyle, particularly involving spending time outdoors does appear to be helpful in preventing myopia or slowing its progression. This is a public health message that could be beneficial, not only for children’s eyes, but for their general health and wellbeing.

What next?

  • Thanks to continued support from the College, the NICER study researchers are contacting the study participants to retest the two cohorts nine years after their original test date, at ages 15-16 years and 21-22 years. 
  • The researchers will continue to analyse the study data, including information about hyperopia and other aspects of refractive error. 
  • The data provides an important baseline, and repeating the study in the future will provide a unique opportunity to determine whether the prevalence of myopia (and other refractive errors) in the UK is changing. 
  • The College will disseminate these findings to members, and highlight the importance of emerging evidence to benefit members in practice and the wider profession.

References: 

  1. O’Donoghue L, McClelland JF, Logan NS, Rudnicka AR, Owen CG, Saunders KJ. Refractive error and visual impairment in school children in Northern Ireland. Br J Ophthalmol. 2010; 94(9):1155-9. 
  2. Logan NS, Shah P, Rudnicka AR. Childhood ethnic differences in ametropia and ocular biometry: the Aston Eye Study. Ophthalmic Physiol Opt. 2011; 31(5):550-8. 
  3. Sorsby A, Benjamin B, Sheridan M, Stone J, Leary GA. Refraction and its components during the growth of the eye from age of three. Memo Med Res Counc. 1961; 301(special):1-67. 
  4. Jones LA, Sinnott LT, Mutti DO, Mitchell GL, Moeschberger ML, Zadnik K. Parental history of myopia, sports and outdoor activities and future myopia. Invest Ophthalmol Vis Sci. 2007; 48(8):3524-32. 
  5. French AN, Morgan IG, Burlutsky G, Mitchell P, Rose KA. Prevalence and 5- to 6- year incidence and progression of myopia and hyperopia in Australian schoolchildren. Ophthalmology. 2013; 120(7):1482-91. 
  6. Jung SK, Lee JH, Kakizaki H, Jee D. Prevalence of myopia and its association with body stature and educational level in 19-year-old male conscripts in Seoul, South Korea. Invest Ophthalmol Vis Sci. 2012; 53(9):5579-83. 
  7. O’Donoghue L, Kapetanankis VV, McClelland JF, Logan NS, Owen CG, Saunders KJ et al. Risk factors for childhood myopia: Findings from the NICER study. Invest Ophthalmol Vis Sci. 2015; 56(3):1524-30. 
  8. McCullough SJ, Breslin KMM, O’Donoghue L, Saunders KJ. A six year prospective profile of refractive error status adults in Northern Ireland-The NICER Study. Ophthalmic Physiol Opt. 2014; 34(6):685-6. 
  9. McCullough SJ, O’Donoghue L, Saunders KJ. Six year refractive change among white children and young adults: Evidence for significant Increase In myopia among white UK children. PLOS ONE. [online]. 2016. 
  10. The College of Optometrists guidance for professional practice (2015).

Acknowledgements: 

This research was jointly funded by The College of Optometrists and Ulster University with support from colleagues and co-authors at Aston University; St George’s, University of London; the University of Sydney; and the Australian National University.