title: Short-term changes in light distortion in orthokeratology subjects.
abstract: OBJECTIVE
  Quantifying adaptation to light distortion of subjects undergoing orthokeratology (OK) for myopia during the first month of treatment.
  
  
  METHODS
  Twenty-nine healthy volunteers (age: 22.34 ± 8.08 years) with mean spherical equivalent refractive error -2.10 ± 0.93D were evaluated at baseline and days 1, 7, 15, and 30 of OK treatment. Light distortion was determined using an experimental prototype. Corneal aberrations were derived from corneal topography for different pupil sizes. Contrast sensitivity function (CSF) was analyzed for frequencies of 1.50, 2.12, 3.00, 4.24, 6.00, 8.49, 12.00, 16.97, and 24.00 cpd under photopic conditions.
  
  
  RESULTS
  Average monocular values of all light distortion parameters measured increased significantly on day 1, returning to baseline after 1 week (P < 0.05 in all cases). Spherical-like aberration stabilized on day 7 for all pupil diameters, while coma-like for smaller pupils only. CSF was significantly reduced on day 1 for all spatial frequencies except for 1.5 cpd, returning to baseline afterwards. Significant correlation was found between light distortion and contrast sensitivity for middle and high frequencies (P < 0.05) after 15 days.
  
  
  CONCLUSIONS
  Despite consistently increased levels of corneal aberrations, light distortion tends to return to baseline after one week of treatment, suggesting that neural adaptation is capable of overcoming optical quality degradation.
authors.affiliation: Private Practice, Onda, 12200 Castellon, Spain ; Optometry Research Group, Department of Optics, Universidad de Valencia, 46100 Valencia, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Santolaria Sanz
authors.affiliation: Optometry Research Group, Department of Optics, Universidad de Valencia, 46100 Valencia, Spain.
authors.forename: Alejandro
authors.identifier: 0000-0001-8014-3279
authors.initials: A
authors.lastname: Cerviño
authors.affiliation: Clinical & Experimental Optometry Research Lab (CEORLab), Center of Physics (Optometry), Universidade do Minho, 4710-057 Braga, Portugal.
authors.forename: Antonio
authors.identifier: 0000-0003-1045-4455
authors.initials: A
authors.lastname: Queiros
authors.affiliation: Department of Optics and Optometry, Universidad Europea de Madrid, 28670 Villaviciosa de Odón, Spain.
authors.forename: Cesar
authors.initials: C
authors.lastname: Villa-Collar
authors.affiliation: Clinical & Experimental Optometry Research Lab (CEORLab), Center of Physics (Optometry), Universidade do Minho, 4710-057 Braga, Portugal.
authors.forename: Daniela
authors.identifier: 0000-0003-2161-6149
authors.initials: D
authors.lastname: Lopes-Ferreira
authors.affiliation: Clinical & Experimental Optometry Research Lab (CEORLab), Center of Physics (Optometry), Universidade do Minho, 4710-057 Braga, Portugal.
authors.forename: Jose Manuel
authors.initials: JM
authors.lastname: González-Méijome
mesh_terms: D000293:Adolescent; D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology; D003315:Cornea / Q000503:physiopathology*; D019781:Corneal Topography / Q000379:methods; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D009216:Myopia / Q000503:physiopathology*; D054158:Orthokeratologic Procedures / Q000379:methods; D012030:Refractive Errors / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult