Orthokeratology(OK)is a clinical technique that uses reverse geometry design rigid contact lenses to reshape the corneal profile and modify its refractive power during overnight lens wear in order to correct refractiv...Orthokeratology(OK)is a clinical technique that uses reverse geometry design rigid contact lenses to reshape the corneal profile and modify its refractive power during overnight lens wear in order to correct refractive error temporarily.OK achieves its reshaping effect through thinning of the central corneal epithelium.This raises concerns about the safety of this modality particularly in terms of microbial keratitis(MK).Since the mid 2000’s,with our increasing understanding of modifiable risk factors for MK in OK the prevalence of MK appears to have reduced significantly.It is now clear that the relative risk of MK in overnight OK is equivalent to other modalities of contact lens wear,provided that safe practice is followed in terms of lens fitting,wear and care.Although OK was originally used predominantly for correction of low to moderate myopic refractive error,its use for myopia control have become more common in recent years.This follows on from published clinical trials demonstrating an average of approximately 45%reduction in axial eye elongation when overnight OK is used in progressive myopic children.But there is significant individual variability in efficacy,and one of the current challenges for OK in myopia control is to identify those children who will benefit most from this particular intervention.Modifying OK lens parameters to customise corneal reshaping for enhanced myopia control efficacy also remains a significant challenge for the future of this modality.展开更多
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 usi...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 wearhas 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.展开更多
文摘Orthokeratology(OK)is a clinical technique that uses reverse geometry design rigid contact lenses to reshape the corneal profile and modify its refractive power during overnight lens wear in order to correct refractive error temporarily.OK achieves its reshaping effect through thinning of the central corneal epithelium.This raises concerns about the safety of this modality particularly in terms of microbial keratitis(MK).Since the mid 2000’s,with our increasing understanding of modifiable risk factors for MK in OK the prevalence of MK appears to have reduced significantly.It is now clear that the relative risk of MK in overnight OK is equivalent to other modalities of contact lens wear,provided that safe practice is followed in terms of lens fitting,wear and care.Although OK was originally used predominantly for correction of low to moderate myopic refractive error,its use for myopia control have become more common in recent years.This follows on from published clinical trials demonstrating an average of approximately 45%reduction in axial eye elongation when overnight OK is used in progressive myopic children.But there is significant individual variability in efficacy,and one of the current challenges for OK in myopia control is to identify those children who will benefit most from this particular intervention.Modifying OK lens parameters to customise corneal reshaping for enhanced myopia control efficacy also remains a significant challenge for the future of this modality.
文摘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 wearhas 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.
