Abstract
Purpose: :
To report the relationship between uncorrected visual acuity and clinically significant refractive error in white school children aged 6-7-years and 12-13-years in Northern Ireland.
Methods: :
A stratified random cluster design was used to recruit children from schools in Northern Ireland. Detailed eye examinations included monocular assessment of visual acuity using a Windows-based computerised test chart, and cycloplegic (1% cyclopentolate) autorefraction. Spherical equivalent refractive data from the right eye were used to classify clinically significant refractive error as myopia of at least -1DS or more myopia, moderate hyperopia of at least +2DS, or astigmatism of at least 1DC whether it occurred in isolation or in association with myopia or hyperopia.
Results: :
Of those invited, 57% (n=399) of 6-7-year-olds and 60% (n=669) of 12-13-year-olds participated. Data are presented for white participants only (99%, n=392 6-7-year-olds; n=661 12-13-year-olds). The optimal cut-off of uncorrected visual acuity to detect clinically significant refractive error (myopia, moderate hyperopia or astigmatism) was 0.12 logMAR in 6-7-year-old children (sensitivity of 51% and specificity of 70%) and 0.04 logMAR (sensitivity 63% and 79%) in 12-13-year-old children. In 12-13-year-old children the optimal cut-off to detect myopia was 0.30 logMAR (sensitivity 92%, specificity 93%).
Conclusions: :
Whilst LogMAR acuity can reliably detect myopia, it does not reliably detect the presence of moderate hyperopia or astigmatism in Northern Irish school children. Further work is required to determine the most appropriate vision screening program to detect childhood refractive error in this population.
Keywords: visual acuity • myopia • hyperopia