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World J Ophthalmol. Aug 12, 2014; 4(3): 63-70
Published online Aug 12, 2014. doi: 10.5318/wjo.v4.i3.63
Orthokeratology lens related infections
Kelvin Ho-Nam Wan, Vishal Jhanji, Alvin L Young
Kelvin Ho-Nam Wan, Department of Ophthalmology, Tuen Mun Hospital and Tuen Mun Eye Center, Hong Kong, China
Vishal Jhanji, Alvin L Young, Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital and Alice Ho Liu Ling Nethersole Hospital, Hong Kong, China
Kelvin Ho-Nam Wan, Vishal Jhanji, Alvin L Young, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
Author contributions: All the authors contributed to this paper.
Correspondence to: Dr. Alvin L Young, MMedSc (Hons), FRCSIrel, Chief of Service, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, China.
Telephone: +852-26322878 Fax: +852-26482943
Received: March 11, 2014
Revised: June 19, 2014
Accepted: June 27, 2014
Published online: August 12, 2014

Orthokeratology is a reversible technique that temporarily changes the curvature of the cornea with the aim of addressing refractive errors. The United States Food and Drug Administration (FDA) granted approval for using reverse geometry contact lenses to correct myopia without any age restriction. Information from the pre-market applications to the FDA was rated as level II evidence. Another unapproved use of overnight orthokeratology is for the prevention of myopic progression. Although orthokeratology is advocated to reduce myopic progression, there are limited long-term studies with substantial evidence of its benefits. Much of this evidence comes from non-robust experimental studies using historical or self-selected controls with relative high dropout rates. Although some positive results have been published in temporarily reducing the myopic refractive error and its progression, the use of these lenses can be associated with serious complications such as microbial keratitis. Microbial keratitis is a potentially vision-threatening adverse response associated with contact lens wear. In fact, contact lens wear has been shown to be the predominant risk factor of microbial keratitis in some developed countries. Most of the published cases on overnight orthokeratology related microbial keratitis occurred in children or adolescents. Parents considering orthokeratology must make an informed decision about its temporary benefit and its potential for permanent loss of vision. The ophthalmic community should be reminded of the potential complications of orthokeratology.

Keywords: Orthokeratology, Infections, Microbial keratitis, Cornea, Corneal ulcer, Contact lens, Myopia

Core tip: Orthokeratology uses specially designed rigid contact lenses to temporarily reshape the cornea to ameliorate refractive errors and it has also been suggested to slow the progression of myopia. None of the published studies to date in assessing its efficacy are rated as level I evidence. Orthokeratology carries the risk of microbial keratitis, which is potentially sight threatening and the safety of orthokeratology remains difficult to assess. Practitioners prescribing orthokeratology must receive appropriate training with respect to the local standards, inform patients and/or their parents of the potential risks, and ensure their patients’ compliance in proper handling of the day to day care of their lenses to minimize the infective risks.