title: Corneal higher-order aberrations induced by overnight orthokeratology.
abstract: OBJECTIVE
  To evaluate corneal higher-order aberrations induced by overnight orthokeratology for myopia.
  
  
  METHODS
  Prospective, noncomparative, consecutive, interventional case series.
  
  
  METHODS
  A prospective study was conducted in 64 eyes of 39 patients with overnight orthokeratology for myopia, who were followed up for at least 3 months and attained uncorrected visual acuity of 20/20 or better. Corneal height data were obtained with computerized videokeratography (TMS-2N, Tomey), and wavefront aberration was derived using Zernike polynomials. Higher-order aberrations of the cornea were calculated for 3- and 6-mm pupils.
  
  
  RESULTS
  Orthokeratology significantly reduced manifest refraction from -2.60 +/- 1.13 (mean +/- SD) diopters to -0.17 +/- 0.31 diopters (P < .0001, paired t test). Root-mean-square (RMS) of third-order (coma-like) aberrations significantly increased by orthokeratology for both 3-mm (P < .0001, paired t test) and 6-mm (P < .0001) pupils. Fourth-order RMS (spherical-like) aberrations increased significantly by the treatment for both 3-mm (P < .0001) and 6-mm (P < .0001) pupils. Vertical coma significantly changed from positive to negative for both 3-mm (P = .0323) and 6-mm (P < .0001) pupils. Horizontal coma significantly increased to the positive direction for both 3-mm (P < .0001) and 6-mm (P < .0001) pupils. Increases in the third- and fourth-order RMS showed significant positive correlations with the amount of myopic correction for 3-mm (Pearson correlation coefficient, r = .452, P = .0001 for third-order RMS, r = .381, P = .0017 for fourth-order RMS) and 6-mm (r = .499, P < .0001, r = .455, P = .0001) pupils.
  
  
  CONCLUSIONS
  Corneal higher-order aberrations significantly increased, even in clinically successful orthokeratology cases. The increases in the higher-order aberrations correlated with the magnitude of myopic correction.
authors.affiliation: Department of Ophthalmology, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan. thiraoka@md.tsukuba.ac.jp
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hiraoka
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Fumiki
authors.initials: F
authors.lastname: Okamoto
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Yoko
authors.initials: Y
authors.lastname: Hirohara
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Mihashi
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Oshika
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003261:Contact Lenses / Q000009:adverse effects*; D003315:Cornea / Q000503:physiopathology; D019781:Corneal Topography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009216:Myopia / Q000628:therapy*; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D012030:Refractive Errors / Q000209:etiology* / Q000503:physiopathology; D014792:Visual Acuity