Abstract
Purpose::
The Aston Eye Study (AES) is a cross-sectional study (started October 2005) to determine the prevalence of refractive error and its associated ocular biometry in a large multi-racial sample of school children from the metropolitan area of Birmingham, United Kingdom.
Methods::
A target sample of 1700 Year 2 (age 6-7 years) and 1200 Year 8 (age 12-13 years) children is being selected from Birmingham schools selected randomly with stratification by area deprivation index (a measure of socio-economic status). Schools with pupils predominantly (>70%) from a single race are excluded. Sample size calculations account for the likely participation rate and the clustering of individuals within schools. Procedures involve standardised protocols to allow for comparison with international population-based data. Visual acuity, non-contact ocular biometry (axial length, corneal radius of curvature and anterior chamber depth using IOLMaster Zeiss, Jena) and cycloplegia (proxymetacaine 0.5% corneal anaesthesia followed by cyclopentolate 1%) binocular open-field autorefraction (Shin-Nippon SRW5000, Japan) are measured in both eyes. Distance and near oculomotor balance (cover test), height and weight are also assessed. Questionnaires for parents (75 items) and Year 8 children (57 items) will allow the influence of environmental factors on refractive error to be examined.
Results::
Data collection is ongoing (currently N=330) with protocols being well received by both parents and children. No adverse incidents or effects have been reported to date. Current data indicate that almost 1 in 10 Year 8 children (N=286) require refractive correction but do not have the provision of spectacles.
Conclusions::
The AES will allow the ocular characteristics of 2900 children from a large metropolitan area of the United Kingdom to be described. The association between educational status, ethnic background and other environmental influences on refractive outcome will be determined.
Keywords: myopia • clinical (human) or epidemiologic studies: prevalence/incidence • clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology