title: Effect of orthokeratology in patients with myopic regression after refractive surgery.
abstract: OBJECTIVE
  To evaluate the clinical effect of orthokeratology (ortho-K) lenses and to introduce the fitting steps of ortho-K lens for myopic regression after keratorefractive surgery.
  
  
  METHODS
  Twenty-one eyes from 12 patients with myopic regression after keratorefractive surgery were fitted with ortho-K lenses and followed up for 12.11±3.68 months. The mean K value of the peripheral cornea was used to speculate preoperative central corneal K value, estimated K. After dispensing the lenses according to estimated K, biomicroscopic examination including fluorescein staining and over-refraction were performed to determine the final K and final lens power.
  
  
  RESULTS
  LogMAR uncorrected visual acuity was 0.48±0.39 before and 0.00±0.00 after wearing ortho-K lenses (p<0.001). Pre-fitted refractive error was -1.87±1.05 diopters (D) in myopia, 0.54±0.42 D in astigmatism, and spherical equivalent of -2.14±1.01 D. At the final visit myopia level and spherical equivalent significantly decreased to -0.73±0.84 D (p<0.001) and -1.01±0.87 D (p<0.001), respectively. Estimated K was 8.07±0.36 mm, and final K used for ortho-K prescription was 8.19±0.30 mm. Final K significantly correlated with K value of pre-fitted peripheral cornea (r=0.737, p<0.001) and estimated K (r=0.721, p<0.001), respectively. There was no correlation between pre-fitted degree of myopia and the Final lens power (r=0.429, p=0.053).
  
  
  CONCLUSIONS
  Ortho-K lenses may be an effective solution for patients with myopic regression following keratorefractive surgery. Estimated K value can be used as reference value in ortho-K prescription.
authors.affiliation: Department of Ophthalmology, Pusan National University School of Medicine & Medical Research Institute, Pusan National University Hospital, Yangsan, South Korea.
authors.forename: Young Min
authors.initials: YM
authors.lastname: Park
authors.affiliation: Park Young Kee Eye Clinic, Seoul, South Korea.
authors.forename: Young Kee
authors.initials: YK
authors.lastname: Park
authors.affiliation: Department of Ophthalmology, Pusan National University School of Medicine & Medical Research Institute, Pusan National University Hospital, Yangsan, South Korea.
authors.forename: Ji-Eun
authors.initials: JE
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Pusan National University School of Medicine & Medical Research Institute, Pusan National University Hospital, Pusan, South Korea. Electronic address: jongsool@pusan.ac.kr.
authors.forename: Jong Soo
authors.initials: JS
authors.lastname: Lee
mesh_terms: D000328:Adult; D003263:Contact Lenses, Hydrophilic; D019781:Corneal Topography; D005260:Female; D006801:Humans; D049008:Keratectomy, Subepithelial, Laser-Assisted / Q000379:methods; D020731:Keratomileusis, Laser In Situ / Q000379:methods; D054018:Lasers, Excimer / Q000627:therapeutic use; D008297:Male; D009216:Myopia / Q000209:etiology / Q000601:surgery / Q000628:therapy*; D054158:Orthokeratologic Procedures; D011183:Postoperative Complications / Q000628:therapy*; D017755:Prosthesis Fitting; D012029:Refraction, Ocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology
keywords: Myopic regression; Orthokeratology; Refractive surgery