The child self-refraction study results from urban Chinese children in Guangzhou

Abstract

Objective: To compare visual and refractive outcomes between self-refracting spectacles (Adaptive Eyecare, Ltd, Oxford, UK), noncycloplegic autorefraction, and cycloplegic subjective refraction.

Design: Cross-sectional study.

Participants: Chinese school-children aged 12 to 17 years.

Methods: Children with uncorrected visual acuity ≤ 6/12 in either eye underwent measurement of the logarithm of the minimum angle of resolution visual acuity, habitual correction, self-refraction without cycloplegia, autorefraction with and without cycloplegia, and subjective refraction with cycloplegia.

Main outcome measures: Proportion of children achieving corrected visual acuity ≥ 6/7.5 with each modality; difference in spherical equivalent refractive error between each of the modalities and cycloplegic subjective refractive error.

Results: Among 556 eligible children of consenting parents, 554 (99.6%) completed self-refraction (mean age, 13.8 years; 59.7% girls; 54.0% currently wearing glasses). The proportion of children with visual acuity ≥ 6/7.5 in the better eye with habitual correction, self-refraction, noncycloplegic autorefraction, and cycloplegic subjective refraction were 34.8%, 92.4%, 99.5% and 99.8%, respectively (self-refraction versus cycloplegic subjective refraction, P<0.001). The mean difference between cycloplegic subjective refraction and noncycloplegic autorefraction (which was more myopic) was significant (-0.328 diopter [D]; Wilcoxon signed-rank test P<0.001), whereas cycloplegic subjective refraction and self-refraction did not differ significantly (-0.009 D; Wilcoxon signed-rank test P = 0.33). Spherical equivalent differed by ≥ 1.0 D in either direction from cycloplegic subjective refraction more frequently among right eyes for self-refraction (11.2%) than noncycloplegic autorefraction (6.0%; P = 0.002). Self-refraction power that differed by ≥ 1.0 D from cycloplegic subjective refractive error (11.2%) was significantly associated with presenting without spectacles (P = 0.011) and with greater absolute power of both spherical (P = 0.025) and cylindrical (P = 0.022) refractive error.

Conclusions: Self-refraction seems to be less prone to accommodative inaccuracy than noncycloplegic autorefraction, another modality appropriate for use in areas where access to eye care providers is limited. Visual results seem to be comparable. Greater cylindrical power is associated with less accurate results; the adjustable glasses used in this study cannot correct astigmatism. Further studies of the practical applications of this modality are warranted.

Financial disclosure(s): Proprietary or commercial disclosure may be found after the references.

Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1

Photograph of the adjustable glasses (Adaptive Eyecare Ltd., Oxford, UK), with the adjustment knobs indicated by the open arrow and the diopter scale on the user-controlled pump indicated by the solid arrow.

Figure 2

Box plot representations of the distribution of spherical equivalent refractive error based on self-refraction (SR), non-cycloplegic auto-refraction (NAR), cycloplegic auto-refraction (CAR), and cycloplegic subjective refraction (CSR). Each box extends from the 25th to the 75th percentile, the interquartile range, with the inside bar representing the median. Whiskers extend to the lower and upper extremes, defined as the 25th percentile minus 1.5 times the interquartile range and the 75th percentile plus 1.5 times the interquartile range.

Figure 3

Bland–Altman plots comparing cycloplegic subjective refractive error (CSR) and each of the following modalities: Self-refraction (SR), noncycloplegic autorefraction (NAR), and cycloplegic autorefraction (CAR). The horizontal lines represent, from top to bottom, the 97.5th percentile, the median and the 2.5th percentile, respectively. D = diopter.

Figure 4

Box plot representation of the difference between self-refraction (SR) and cycloplegic subjective refraction (CSR) for different levels of cycloplegic subjective refractive error. D = diopter.