title: Mesopic contrast sensitivity and ocular higher-order aberrations after overnight orthokeratology.
abstract: OBJECTIVE
  To investigate mesopic contrast sensitivity and night driving ability in eyes undergoing overnight orthokeratology, and to analyze the relationship among mesopic contrast sensitivity, ocular higher-order aberrations, and myopic correction.
  
  
  METHODS
  Prospective, noncomparative, consecutive case series.
  
  
  METHODS
  In 44 eyes of 22 subjects (mean age +/- standard deviation [SD], 24.0 +/- 3.2 years) with orthokeratology, ocular aberrations and mesopic contrast sensitivity were determined before and three months after commencement of the procedure. Mean spherical equivalent refraction +/- SD was -2.34 +/- 0.99 diopters at baseline. Mesopic contrast sensitivity with and without glare was assessed using the Mesotest II (Oculus, Wetzlar, Germany).
  
  
  RESULTS
  Orthokeratology significantly reduced the log mesopic contrast sensitivity from 0.25 +/- 0.08 to 0.08 +/- 0.10 without glare (P < .0001, Wilcoxon) and from 0.21 +/- 0.11 to 0.07 +/- 0.10 with glare (P < .0001). The proportion of eyes that fulfilled the German standard recommendation level for night driving was 36%. The induced changes in log mesopic contrast sensitivity showed significant negative correlation with the changes in third-order (r = -0.490, P = .0013 without glare; r = -0.362, P = .0177 with glare; Spearman rank correlation coefficient) and fourth-order root mean square (r = -0.586, P = .0001 and r = -0.306, P = .0450, respectively). Furthermore, significant correlation was found between the amount of myopic correction and the induced changes in log mesopic contrast sensitivity (r = -0.442, P = .0038 without glare; r = -0.464, P = .0024 with glare). The induced changes in higher-order aberrations significantly correlated with the amount of myopic correction (P < .0001, Pearson correlation coefficient).
  
  
  CONCLUSIONS
  Mesopic contrast sensitivity after overnight orthokeratology is deteriorated significantly as ocular higher-order aberrations increase, and these changes depend on the amount 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: Chikako
authors.initials: C
authors.lastname: Okamoto
authors.forename: Yuko
authors.initials: Y
authors.lastname: Ishii
authors.forename: Tomonori
authors.initials: T
authors.lastname: Takahira
authors.forename: Tetsuhiko
authors.initials: T
authors.lastname: Kakita
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Oshika
mesh_terms: D000328:Adult; D001334:Automobile Driving; D015350:Contrast Sensitivity; D003623:Dark Adaptation; D005260:Female; D019466:Glare; D006801:Humans; D008297:Male; D009216:Myopia / Q000628:therapy; D054158:Orthokeratologic Procedures / Q000009:adverse effects*; D011446:Prospective Studies; D012030:Refractive Errors / Q000209:etiology*; D014786:Vision Disorders / Q000209:etiology*