title: Changes in Peripheral Refractive Profile after Orthokeratology for Different Degrees of Myopia.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effect of orthokeratology for different degrees of myopia correction in the relative location of tangential (F(T)) and sagittal (F(S)) power errors across the central 70° of the visual field in the horizontal meridian.
  
  
  METHODS
  Thirty-four right eyes of 34 patients with a mean age of 25.2 ± 6.4 years were fitted with Paragon CRT (Mesa, AZ) rigid gas permeable contact lenses to treat myopia (-2.15 ± 1.26D, range: -0.88 to -5.25D). Axial and peripheral refraction were measured along the central 70° of the horizontal visual field with the Grand Seiko WAM5500 open-field auto-refractor. Spherical equivalent (M), as well as tangential (FT) and sagittal power errors (FS) were obtained. Analysis was stratified in three groups according to baseline spherical equivalent: Group 1 [M(Baseline) = -0.88 to -1.50D; n = 11], Group 2 [M(Baseline) = -1.51 to -2.49D; n = 11], and Group 3 [M(Baseline) = -2.50 to -5.25D; n = 12].
  
  
  RESULTS
  Spherical equivalent was significantly more myopic after treatment beyond the central 40° of the visual field (p < 0.001). FT became significantly more myopic for all groups in the nasal and temporal retina with 25° (p ≤ 0.017), 30° (p ≤ 0.007) and 35° (p ≤ 0.004) of eye rotation. Myopic change in FS was less consistent, achieving only statistical significance for all groups at 35° in the nasal and temporal retina (p ≤ 0.045).
  
  
  CONCLUSIONS
  Orthokeratology changes significantly FT in the myopic direction beyond the central 40° of the visual field for all degrees of myopia. Changes induced by orthokeratology in relative peripheral M, FT and FS with 35° of eye rotation were significantly correlated with axial myopia at baseline.
authors: a Clinical & Experimental Optometry Research Lab, School of Sciences (Optometry), University of Minho , Braga , Portugal and.
authors: José Manuel
authors: JM
authors: González-Méijome
authors: a Clinical & Experimental Optometry Research Lab, School of Sciences (Optometry), University of Minho , Braga , Portugal and.
authors: Miguel A
authors: MA
authors: Faria-Ribeiro
authors: a Clinical & Experimental Optometry Research Lab, School of Sciences (Optometry), University of Minho , Braga , Portugal and.
authors: Daniela P
authors: DP
authors: Lopes-Ferreira
authors: a Clinical & Experimental Optometry Research Lab, School of Sciences (Optometry), University of Minho , Braga , Portugal and.
authors: Paulo
authors: P
authors: Fernandes
authors: b Department of Optics II (Optometry and Vision) , School of Optics, Universidad Complutense de Madrid , Madrid , Spain.
authors: Gonzalo
authors: G
authors: Carracedo
authors: a Clinical & Experimental Optometry Research Lab, School of Sciences (Optometry), University of Minho , Braga , Portugal and.
authors: Antonio
authors: A
authors: Queiros
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000628:therapy; D003261:Contact Lenses; D005260:Female; D006801:Humans; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000628:therapy*; D054158:Orthokeratologic Procedures; D012029:Refraction, Ocular / Q000502:physiology*; D014794:Visual Fields; D055815:Young Adult
keywords: Field curvature; myopia; orthokeratology; peripheral astigmatism