title: Peripheral defocus and myopia progression in myopic children randomly assigned to wear single vision and progressive addition lenses.
abstract: OBJECTIVE
  To determine the effect of progressive addition lenses (PALs) and single vision lenses (SVLs) on peripheral defocus in myopic children, and to compare the effect of myopic versus hyperopic peripheral defocus on foveal myopia progression.
  
  
  METHODS
  Eighty-four myopic children aged 6 to 11 years with spherical equivalent (SE) cycloplegic autorefraction between -0.75 diopters (D) and -4.50 D were randomly assigned to wear SVLs or PALs. Aberrometry measurements of the eye and spectacles were made centrally, 30° nasally, temporally, and superiorly, and 20° inferiorly on the retina using a Complete Ophthalmic Analysis System for Vision Research (COAS-VR). The association between peripheral defocus and the 1-year change in central myopia was investigated.
  
  
  RESULTS
  SVLs caused a hyperopic shift in peripheral defocus at all locations (all P ≤ 0.0003). PALs caused a myopic shift in peripheral defocus in three of four locations measured (all P ≤ 0.01) with the greatest shift superiorly due to the PAL addition (-1.04 ± 0.30 D). Superior retinal defocus when wearing either SVLs or PALs was associated with the 1-year change in central myopia. The adjusted 1-year change in central SE myopia was -0.38 D for children with absolute superior myopic defocus (n = 67) and -0.65 D for children with absolute superior hyperopic defocus (n = 17; difference = 0.27 D; P = 0.002).
  
  
  CONCLUSIONS
  PALs caused a myopic shift in peripheral defocus. Superior myopic defocus was associated with less central myopia progression. These data support the continued investigation of optical designs that result in peripheral myopic defocus as a potential way to slow myopia progression. (ClinicalTrials.gov number, NCT00335049.).
authors.affiliation: University of Houston College of Optometry, Houston, Texas 77204-2020, USA. dberntsen@optometry.uh.edu
authors.forename: David A
authors.initials: DA
authors.lastname: Berntsen
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Barr
authors.forename: Donald O
authors.initials: DO
authors.lastname: Mutti
authors.forename: Karla
authors.initials: K
authors.lastname: Zadnik
mesh_terms: D002648:Child; D018450:Disease Progression; D005139:Eyeglasses; D005260:Female; D006801:Humans; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000628:therapy*; D012029:Refraction, Ocular / Q000502:physiology; D014794:Visual Fields / Q000502:physiology*
keywords: children; myopia progression; peripheral defocus; progressive addition lenses; single vision lenses