A comparison of measures of reading and intelligence as risk factors for the development of myopia in a UK cohort of children
- Cathy Williams (cathy.williams{at}bristol.ac.uk),
- Laura Miller (l.l.miller{at}bristol.ac.uk),
- Gus Gazzard (gus.gazzard{at}demon.co.uk),
- Seang-Mei Saw (cofsawsm{at}nus.edu.sg)
- Centre for Child and Adolescent Health, University of Bristol, United Kingdom
- Dept of Social Medicine, University of Bristol, UK, United Kingdom
- Institute of Ophthalmology, London, UK, United Kingdom
- National University of Singapore, Singapore
- Published Online First 20 June 2008
Abstract
Purpose Evidence suggests that reading may be an important risk factor for myopia but recent reports find that performance in non-verbal intelligence tests may be more important or that near-work is not associated with myopia.
Methods Non-cycloplegic autorefraction data were available at the ages of 7 and 10 years from a birth cohort study. Children whose right eye spherical equivalent autorefraction was ≤</= −-1.50 D were categorized as "likely to be myopic". We tested associations between school-based SATS (Standardized Assesment Tests) for reading and mathematics, maternal report of child liking reading, the WORD (Wescher Objective Reading Dimension) test results, verbal and non-verbal IQ and the child being in the "likely to be myopic" group.
Results 6871 children (59.7% of remaining cohort) had refractive and risk factor data at 7, of whom 1.5% were in the "likely to be myopic" group. Predictors (Odds Ratios, OR: 95%CI) of concurrent (at 7) risk for myopia were good performance in the SATS reading (2.60:1.61, 4.19; p < 0.001), SATS maths (1.90: 1.19, 3.05; p = 0.008), the WORD (2.72:1.60, 4.64; p = 0.001) and verbal IQ tests (1.99, 1.13, 3.52; p =0.055) after adjustment for the number of myopic parents (p = 0.014) and ethnicity (p =0.129). However the strongest predictor of incident myopia developing between 7 and 10 years was the parental report of whether the child liked reading: (4.05:1.27, 12.89; p = 0.031), adjusted for parental myopia (p = 0.033) and ethnicity (p = 0.008).
Conclusions Factors associated with reading may play a part in myopia development. Further comparisons of different measures of reading-related activity or verbal ability may help clarify which of the related behavioural characteristics are causally related to myopia prevalence.
