title: 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.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  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.
  
  
  METHODS
  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.
  
  
  BACKGROUND
  Proprietary or commercial disclosure may be found after the references.
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat Sen University, Guangzhou, PRC. mingguang_he@yahoo.com
authors.forename: Mingguang
authors.initials: M
authors.lastname: He
authors.forename: Nathan
authors.initials: N
authors.lastname: Congdon
authors.forename: Graeme
authors.initials: G
authors.lastname: MacKenzie
authors.forename: Yangfa
authors.initials: Y
authors.lastname: Zeng
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Silver
authors.forename: Leon
authors.initials: L
authors.lastname: Ellwein
mesh_terms: D000293:Adolescent; D002648:Child; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004867:Equipment Design; D005139:Eyeglasses; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D015995:Prevalence; D012029:Refraction, Ocular / Q000502:physiology*; D012030:Refractive Errors / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D014505:Urban Population; D014787:Vision Tests; D014792:Visual Acuity