School vision screening programmes: the benefits of including measurements of refractive error.
Following a comprehensive review of vision screening in 1997, various research studies have since been conducted and extensive literature is now available on the detection of amblyopia in vision screening programmes. However, little attention has been paid to the role of detecting refractive error namely hyperopia thus far. The purpose of this thesis was to determine the benefits of including a refractive error assessment at vision screening. The value of including a refraction was investigated by retrospectively analysing those children who had passed screening but were later found to have a significant refractive error. To ascertain which method of refraction would be most appropriate, non-cycloplegic and cycloplegic retinoscopy readings were used to compare the level of agreement of the Welch Allyn Sure Sight (WASS) autorefractor. The accuracy of using visual acuity assessment alone for the detection of amblyopia was also assessed. Overall, it was found that a refractive error assessment does have a role in vision screening. Double the number of children were detected as having a significant refractive error compared to screening without a refractive error assessment. These studies demonstrate that the WASS, which is a portable and easy to use device, has reasonable accuracy within a range of refractive errors. The sensitivity and specificity of the vision screening programme when refractive error assessment was included was very good. It was found that visual acuity assessment for detection for amblyopia was fair, however it could be improved if a refractive error assessment was included at screening.
Vision, Visual accuity, Screening, Visual development, Children, Refractive error, Autorefractor, Amblyopia, Strabismus, School vision screening
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