title: Long-term Efficacy of Orthokeratology Contact Lens Wear in Controlling the Progression of Childhood Myopia.
abstract: The primary outcome of this study is to compare the axial length growth of white European myopic children wearing orthokeratology contact lenses (OK) to a control group (CT) over a 7-year period.
  
  
  
  Subjects 6-12 years of age with myopia -0.75 to -4.00DS and astigmatism ≤1.00DC were prospectively allocated OK or distance single-vision spectacles (SV) correction. Measurements of axial length (Zeiss IOLMaster), corneal topography, and cycloplegic refraction were taken at 6-month intervals over a 2-year period. Subjects were invited to return to the clinic approximately 5 years later (i.e., 7 years after the beginning of the study) for assessment of their ocular refractive and biometric components. The CT consisted of 4 SV and 12 subjects who switched from SV to soft contact lens wear after the initial 2 years of SV lens wear. Changes in axial length relative to baseline over a 7-year period were compared between groups.
  
  
  
  Fourteen and 16 subjects from the OK and CT groups, respectively, were examined 6.7 ± 0.5 years after the beginning of the study. Statistically significant changes in the axial length were found over time and between groups (both p < 0.001), but not for the time*group interaction (p = 0.125). The change in the axial length for the OK group was 22% (p = 0.328), 42% (p = 0.007), 40% (p = 0.020), 41% (p = 0.013), and 33% (p = 0.062) lower than the CT group following 6, 12, 18, 24, and 84 months of lens wear, respectively.
  
  
  
  A trend toward a reduction in the rate of axial elongation of the order of 33% was found in the OK group in comparison to the CT group following 7 years of lens wear.
authors: a Menicon R&D Innovation Center, Research & Development, Menicon Co., Ltd , Geneva , Switzerland.
authors: Jacinto
authors: J
authors: Santodomingo-Rubido
authors: b Optics & Optometry Department, Faculty of Health Sciences , Universidad Europea , Madrid , Spain.
authors: César
authors: C
authors: Villa-Collar
authors: c School of Life and Health Sciences, Department of Optometry , Ophthalmic Research Group, Aston University , Birmingham , UK.
authors: Bernard
authors: B
authors: Gilmartin
authors: b Optics & Optometry Department, Faculty of Health Sciences , Universidad Europea , Madrid , Spain.
authors: Ramón
authors: R
authors: Gutiérrez-Ortega
authors: a Menicon R&D Innovation Center, Research & Development, Menicon Co., Ltd , Geneva , Switzerland.
authors: Keiji
authors: K
authors: Sugimoto
mesh_terms: D058452:Axial Length, Eye / Q000473:pathology*; D002648:Child; D003263:Contact Lenses, Hydrophilic; D019781:Corneal Topography; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009216:Myopia / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D054158:Orthokeratologic Procedures / Q000379:methods*; D012029:Refraction, Ocular; D013997:Time Factors; D016896:Treatment Outcome
keywords: Axial length; long-term efficacy; myopia control; myopia progression; orthokeratology