A comparison of measures of reading and intelligence as risk factors for the development of myopia in a UK cohort of children.
OBJECTIVE
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 <or=-1.50 D were categorised as "likely to be myopic." The authors tested associations between school-based Standardised Assesment Tests (SATS) for reading and mathematics, maternal report of child liking reading, the Wescher Objective Reading Dimension (WORD) 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.
Centre for Child and Adolescent Health, University of Bristol, Bristol, UK. cathy.williams@bristol.ac.uk
C
C
Williams
L L
LL
Miller
G
G
Gazzard
S M
SM
Saw
D044466:Asian People / Q000706:statistics & numerical data; D002648:Child; D004522:Educational Status; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D007360:Intelligence; D008137:Longitudinal Studies; D008297:Male; D009216:Myopia / Q000208:ethnology / Q000209:etiology* / Q000235:genetics; D009483:Neuropsychological Tests; D011932:Reading; D012029:Refraction, Ocular; D012307:Risk Factors