title: A randomized trial of rigid gas permeable contact lenses to reduce progression of children's myopia.
abstract: OBJECTIVE
  To test whether rigid gas permeable (RGP) contact lens wear can reduced the rate of myopia progression in school age children.
  
  
  METHODS
  Randomized clinical trial.
  
  
  METHODS
  
  
  
  METHODS
  Single clinical center.
  
  
  METHODS
  Both eyes of 428 Singaporean children.
  
  
  METHODS
  6 through 12 years of age with myopia between -1 and -4 diopters, astigmatism <or= 2 diopters, no prior contact lens wear, no other ocular pathologies.
  
  
  METHODS
  Spectacle or RGP lens correction for myopia. After a 3-month adaptation period, 383 children were followed, and 298 (78%) remained after 24 months.
  
  
  METHODS
  Cycloplegic subjective refraction, keratometry, and axial length measured at 12 and 24 months.
  
  
  RESULTS
  Children who adapted to contact lenses wore them for a median of 7 hours per day, but no more than 40% wore them at least 8 hours per day, 7 days per week. Spectacles were worn for a median of 15 hours per day at the time of the 24-month follow-up. There was an increase in the spherical equivalent of -1.33 and -1.28 diopters (P =.64), and axial length increased by 0.84 and 0.79 mm (P =.38) over 2 years among children randomized to contact lenses and spectacles, respectively. Adjustment for baseline differences between the groups and for hours per day of contact lens wear did not alter these findings.
  
  
  CONCLUSIONS
  Rigid gas permeable lenses did not slow the rate of myopia progression, even among children who used them regularly and consistently. It is unlikely that this intervention holds promise as a method by which to slow the rate of progression of myopia in children.
authors.affiliation: Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205-2103, USA. jkatz@jhsph.edu
authors.forename: Joanne
authors.initials: J
authors.lastname: Katz
authors.forename: Oliver D
authors.initials: OD
authors.lastname: Schein
authors.forename: Brian
authors.initials: B
authors.lastname: Levy
authors.forename: Tom
authors.initials: T
authors.lastname: Cruiscullo
authors.forename: Seang Mei
authors.initials: SM
authors.lastname: Saw
authors.forename: Uma
authors.initials: U
authors.lastname: Rajan
authors.forename: Tat Keong
authors.initials: TK
authors.lastname: Chan
authors.forename: Chong
authors.initials: C
authors.lastname: Yew Khoo
authors.forename: Sek Jin
authors.initials: SJ
authors.lastname: Chew
mesh_terms: D002648:Child; D003261:Contact Lenses; D018450:Disease Progression; D005139:Eyeglasses; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000628:therapy*; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D016896:Treatment Outcome