Clinical trial NCT00962208: Retardation of Myopia in Orthokeratology
Official title: Orthokeratology for Myopic Control in Chinese Children - a Randomized Clinical Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Myopia
Keywords: children
corneal reshaping
myopia
myopia control
orthokeratology
Lead sponsor: The Hong Kong Polytechnic University
Sponsor class: OTHER
Collaborators: name: Menicon Co., Ltd.
First posted: 2009-08-19
Enrollment: 102
Sex: ALL
Minimum age (years): 6
Maximum age (years): 10
Standard ages: CHILD
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The primary aim of this study is to evaluate and compare the eyeball elongation in children wearing orthokeratology lenses and single-vision spectacles.

Detailed description: Prevalence of myopia is high in Asian countries like Hong Kong. Orthokeratology has shown potential in slowing myopic progression but the efficacy is yet to be confirmed by a randomized clinical trial (RCT). The current RCT aims at studying the efficacy of orthokeratology in retardation of myopic progression by comparing the eye growth in terms of axial length elongation in children wearing orthokeratology lenses (study group) and those wearing single-vision spectacles (control group).

Eligibility criteria: Inclusion Criteria:

* Myopia (refractive sphere): \> 0.50D and ≤ 4.00D
* Astigmatism: \< ½ of myopia; with-the-rule astigmatism (axes 180 +/- 30) ≤1.25D; astigmatism of other axes ≤ 0.50D
* Spherical equivalent (SE): \> 0.75D and ≤ 4.50D
* Anisometropia: ≤ 1.50D in both refractive sphere, refractive cylinder and SE
* Best corrected monocular visual acuity: equal to or better than 0.10 in logMAR scale in both eyes
* Willingness for randomization
* Willingness to wear contact lenses or spectacles on a daily basis
* Availability for follow-up for at least 2 years

Exclusion Criteria:

* Strabismus at distance or near
* Contraindication for contact lens wear and orthokeratology (e.g. limbus to limbus corneal cylinder and dislocated corneal apex
* Prior experience with the use of rigid lenses (including orthokeratology)
* Prior experience with myopia control treatment (e.g. refractive therapy or progressive add spectacles)
* Systemic or ocular conditions which may affect contact lens wear (e.g. allergy and medication)
* Systemic or ocular conditions which may affect refractive development (e.g. Down syndrome, ptosis)

Primary outcomes:
measure: Axial Elongation in the Study and Control Subjects Who Completed the Two Years Study
timeFrame: 2 years
Secondary outcomes:
measure: Determine the Incidence of Adverse Effects in Cornea, the Palpebral, Bulbar and Tarsal Conjunctiva in the Study and the Control Groups
timeFrame: 2 years
measure: Determine Changes in Other Ocular Parameters (e.g. Corneal Biomechanics and Aberration) Associated With Orthokeratology Lens Wear
timeFrame: 2 years
Other outcomes:
Locations:
city: Hong Kong
country: China
facility: School of Optometry, The Hong Kong Polytechnic University
state: Hong Kong
Study officials:
affiliation: The Hong Kong Polytechnic University
name: Pauline Cho, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Cho P, Cheung SW, Edwards M. The longitudinal orthokeratology research in children (LORIC) in Hong Kong: a pilot study on refractive changes and myopic control. Curr Eye Res. 2005 Jan;30(1):71-80. doi: 10.1080/02713680590907256.
citation: Walline JJ, Jones LA, Sinnott LT. Corneal reshaping and myopia progression. Br J Ophthalmol. 2009 Sep;93(9):1181-5. doi: 10.1136/bjo.2008.151365. Epub 2009 May 4.
citation: Cho P, Cheung SW. Retardation of myopia in Orthokeratology (ROMIO) study: a 2-year randomized clinical trial. Invest Ophthalmol Vis Sci. 2012 Oct 11;53(11):7077-85. doi: 10.1167/iovs.12-10565.
citation: Cheung SW, Cho P. Validity of axial length measurements for monitoring myopic progression in orthokeratology. Invest Ophthalmol Vis Sci. 2013 Mar 5;54(3):1613-5. doi: 10.1167/iovs.12-10434.
citation: Chan KY, Cheung SW, Cho P. Clinical performance of an orthokeratology lens fitted with the aid of a computer software in Chinese children. Cont Lens Anterior Eye. 2012 Aug;35(4):180-4. doi: 10.1016/j.clae.2012.01.004. Epub 2012 Mar 3.