A 2-year Longitudinal Study on the Structural and Optical Effects of Orthokeratology Treatment on Eye
Study Overview
Status
Status
Conditions
Conditions
Intervention / Treatment
Intervention / Treatment
Study Type
Study Type
Enrollment (Actual)
Enrollment
Phase
Phase
- Not Applicable
Contacts and Locations
Study Locations
-
-
-
Hong Kong, China
- School of Optometry, The Hong Kong Polytechnic University
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-
Participation Criteria
Eligibility Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
- 6 to 10 years old
- Myopia: between 0.50 D and 4.00 D in both eyes
- Astigmatism: <1.50 D; ≤ 1.25 D for with-the-rule astigmatism (axes 180 ± 30); ≤ 0.50 D for astigmatism of other axes in both eyes
- Anisometropia: ≤ 1.50 D
- Symmetrical corneal topography with corneal toricity <2.00 D in both eyes
- Agree for randomization
Exclusion Criteria:
- Contraindications for orthokeratology wear (e.g. limbus-to-limbus corneal cylinder and dislocated corneal apex)
- Any type of strabismus or amblyopia
- Myopic treatment (e.g. refractive surgery and progressive lens wear for myopic control) before and during the study period
- Rigid contact lenses (including orthokeratology lenses) experience
- Systemic condition which might affect refractive development (for example, Down syndrome, Marfan's syndrome)
- Ocular conditions which might affect the refractive error (for example, cataract, ptosis)
- Poor compliance for lens wear or follow-up
Study Plan
How is the study designed?
Design Details
- Primary Purpose: TREATMENT
- Allocation: RANDOMIZED
- Interventional Model: PARALLEL
- Masking: SINGLE
Number of Arms
Arms and Interventions
Participant Group / ArmParticipant Group / Arm |
Intervention / TreatmentIntervention / Treatment |
|---|---|
|
NO_INTERVENTION: Single-vision glasses
Subjects wearing single-vision glasses CR-39 of refractive index 1.56.
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SHAM_COMPARATOR: Orthokeratology with normal compression factor
Subjects wearing orthokeratology lenses of normal compression factor about 0.50-0.75D.
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Other Names:
|
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ACTIVE_COMPARATOR: Orthokeratology with increased compression factor
Subjects wearing orthokeratology lenses of increased compression factor about 1.50-1.75D.
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Other Names:
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What is the study measuring?
Primary Outcome Measures
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Axial length
Time Frame: every 6 monthly in 2 years
|
axial progression of the eyeball
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every 6 monthly in 2 years
|
Secondary Outcome Measures
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Ocular aberration measured by Complete Ophthalmic Analysis System (COAS) aberrometer
Time Frame: every 6 monthly in 2 years
|
ocular aberration measured by Complete Ophthalmic Analysis System (COAS) aberrometer
|
every 6 monthly in 2 years
|
|
Corneal biomechanics (corneal response using ocular response)
Time Frame: every 6 monthly in 2 years
|
corneal response using ocular response
|
every 6 monthly in 2 years
|
|
Accommodation lag measured by Complete Ophthalmic Analysis System (COAS) aberrometer
Time Frame: every 6 monthly in 2 years
|
accommodation lag measured by Complete Ophthalmic Analysis System (COAS) aberrometer using different accommodation targets
|
every 6 monthly in 2 years
|
|
Choroidal thickness captured by Optical Coherent Tomographer (OCT)
Time Frame: every 6 monthly in 2 years
|
choroidal thickness captured by Optical Coherent Tomographer (OCT) and measured using a customized software
|
every 6 monthly in 2 years
|
Collaborators and Investigators
Sponsor
Sponsor
Collaborators
Collaborators
Publications and helpful links
General Publications
- 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.
- Lam CS, Lam CH, Cheng SC, Chan LY. Prevalence of myopia among Hong Kong Chinese schoolchildren: changes over two decades. Ophthalmic Physiol Opt. 2012 Jan;32(1):17-24. doi: 10.1111/j.1475-1313.2011.00886.x.
- 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.
- Chen C, Cheung SW, Cho P. Myopia control using toric orthokeratology (TO-SEE study). Invest Ophthalmol Vis Sci. 2013 Oct 3;54(10):6510-7. doi: 10.1167/iovs.13-12527.
- Gonzalez-Meijome JM, Villa-Collar C, Queiros A, Jorge J, Parafita MA. Pilot study on the influence of corneal biomechanical properties over the short term in response to corneal refractive therapy for myopia. Cornea. 2008 May;27(4):421-6. doi: 10.1097/ICO.0b013e318164e49d.
- Wolffsohn JS, Safeen S, Shah S, Laiquzzaman M. Changes of corneal biomechanics with keratoconus. Cornea. 2012 Aug;31(8):849-54. doi: 10.1097/ICO.0b013e318243e42d.
- Tse DY, Lam CS, Guggenheim JA, Lam C, Li KK, Liu Q, To CH. Simultaneous defocus integration during refractive development. Invest Ophthalmol Vis Sci. 2007 Dec;48(12):5352-9. doi: 10.1167/iovs.07-0383.
- Chan B, Cho P, Mountford J. The validity of the Jessen formula in overnight orthokeratology: a retrospective study. Ophthalmic Physiol Opt. 2008 May;28(3):265-8. doi: 10.1111/j.1475-1313.2008.00545.x.
- Wan K, Lau JK, Cheung SW, Cho P. Orthokeratology with increased compression factor (OKIC): study design and preliminary results. BMJ Open Ophthalmol. 2020 May 4;5(1):e000345. doi: 10.1136/bmjophth-2019-000345. eCollection 2020.
Study record dates
Study Major Dates
Study Start (ACTUAL)
Study Start
Primary Completion (ACTUAL)
Primary Completion
Study Completion (ACTUAL)
Study Completion
Study Registration Dates
First Submitted
First Submitted
First Submitted That Met QC Criteria
First Submitted That Met QC Criteria
First Posted (ESTIMATE)
First Posted
Study Record Updates
Last Update Posted (ACTUAL)
Last Update Posted
Last Update Submitted That Met QC Criteria
Last Update Submitted That Met QC Criteria
Last Verified
Last Verified
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
Other Study ID Numbers
- HSEARS20150909002
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