title: The Safety of Orthokeratology--A Systematic Review.
abstract: OBJECTIVE
  The aim of this review is to evaluate the ocular safety of orthokeratology (OrthoK) treatment of myopia correction and retardation.
  
  
  METHODS
  Clinical studies published in English and Chinese were identified from MEDLINE, EMBASE CNKI, CQVIP, and WANFANG DATA (all from 1980 to April 2015). The reference lists of the studies and the Science Citation Index were also searched.
  
  
  METHODS
  Relevant clinical studies including case series, case reports, patient/practitioner surveys, retrospective and prospective cohort studies, and clinical trials were all included in the review. The material of OrthoK lenses was limited to gas-permeable lens.
  
  
  RESULTS
  This review incorporated a total of 170 publications, including 58 English and 112 Chinese literature. The risk of microbial keratitis in overnight OrthoK was similar to that of other overnight modality. The most common complication was corneal staining. Other clinically insignificant side effects included epithelial iron deposit, prominent fribrillary lines, and transient changes of corneal biomechanical properties. There was no long-term effect of OrthoK on corneal endothelium.
  
  
  CONCLUSIONS
  There is sufficient evidence to suggest that OrthoK is a safe option for myopia correction and retardation. Long-term success of OrthoK treatment requires a combination of proper lens fitting, rigorous compliance to lens care regimen, good adherence to routine follow-ups, and timely treatment of complications.
authors.affiliation: School of Optometry (Y.M.L.), University of California, Berkeley, CA; and Optometry and Ophthalmology Center (P.X.), Peking University, Beijing, China.
authors.forename: Yue M
authors.initials: YM
authors.lastname: Liu
authors.forename: Peiying
authors.initials: P
authors.lastname: Xie
mesh_terms: D002648:Child; D002675:Child, Preschool; D000068456:Clinical Studies as Topic; D003261:Contact Lenses / Q000009:adverse effects; D003316:Corneal Diseases / Q000209:etiology; D015817:Eye Infections / Q000209:etiology; D006801:Humans; D009216:Myopia / Q000517:prevention & control / Q000628:therapy*; D054158:Orthokeratologic Procedures / Q000009:adverse effects / Q000379:methods*; D014792:Visual Acuity