title: Sustainability of orthokeratology as demonstrated by corneal topography.
abstract: OBJECTIVE
  To determine the sustaining effects of orthokeratology.
  
  
  METHODS
  This study enrolled 58 eyes with moderate myopia. LK-DM lenses (Lucid Korea Dream Lens) were fitted daily for at least eight hours on an overnight regimen. The effects of orthokeratology and it's sustainability throughout the day were recorded twice; immediately after removal in the morning and eight hours later. Sustainability was measured by comparing the changes from morning to afternoon for best uncorrected visual acuity, apical corneal power, keratometric values, spherical equivalent and induced astigmatism.
  
  
  RESULTS
  UCVA demonstrated improved values at all follow up periods. Fluctuations during the day stabilized after 4 weeks of lens wear. K values averaged a mean of 42.4 mm at baseline, and reduced to 40.9 mm by week 12. Unaided logMAR visual acuity changed from 0.94+/-0.14 at baseline to -0.11+/-0.17 by week 12. The sustainability of orthokeratology, defined as the difference between morning and afternoon values of unaided logMAR visual acuity, increased from -0.82 on day 1 to -0.11 on week 12.
  
  
  CONCLUSIONS
  UCVA and spherical refractive error did not change to a significant degree after 4 weeks. Although statistically insignificant minute fluctuations during the day were observed up to week 12, these fluctuations decreased to a statistically significant level after week 4.
authors.affiliation: Department of Ophthalmology, Bundang Jaesang General Hospital, Daejin Medical Center, Sungnam, Korea.
authors.forename: Sung Yong
authors.initials: SY
authors.lastname: Kang
authors.forename: Bong Kyun
authors.initials: BK
authors.lastname: Kim
authors.forename: Young Ja
authors.initials: YJ
authors.lastname: Byun
mesh_terms: D000293:Adolescent; D000328:Adult; D003262:Contact Lenses, Extended-Wear; D003315:Cornea / Q000473:pathology*; D019781:Corneal Topography; D004867:Equipment Design; D005500:Follow-Up Studies; D006801:Humans; D009216:Myopia / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D012029:Refraction, Ocular / Q000502:physiology; D012720:Severity of Illness Index; D013499:Surface Properties; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology