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CompletedNCT02643342Updated Jul 30, 2020

A 2-year Longitudinal Study on the Structural and Optical Effects of Orthokeratology Treatment on Eye

An interventional study of Orthokeratology in Myopic Progression, sponsored by The Hong Kong Polytechnic University. Completed at 1 site in China. Open to participants aged 6 Years to 10 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2020-07-30.

Sponsored by The Hong Kong Polytechnic University · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
99
Allocation
Randomized
Ages
6 Years to 10 Years
Sex
All
01

Study summary

This is a two-year longitudinal study investigating the optical and structural effects of increased compression factor of orthokeratology lens on eyes and the corresponding effect on change in choroidal thickness and therefore myopic control.

02

Conditions studied

  • Myopic Progression

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Keywords

  • myopia control
  • orthokeratology
03

In context

Disease Progression

544 studies on the registry are indexed under Disease Progression; 144 are open to participants now.

This study's enrollment of 99 is above the median of 87 across 266 interventional studies indexed under Disease Progression.

Browse Disease Progression studies →

Lead sponsor

The Hong Kong Polytechnic University is the lead sponsor of 659 studies on the registry; 250 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
6 Years to 10 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

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

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
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Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Outcomes assessor)
Enrollment
99 participants (actual)

Study arms

  • No intervention
    Single-vision glasses

    Subjects wearing single-vision glasses CR-39 of refractive index 1.56.

  • Sham comparator
    Orthokeratology with normal compression factor

    Subjects wearing orthokeratology lenses of normal compression factor about 0.50-0.75D.

    Device: Orthokeratology

  • Active comparator
    Orthokeratology with increased compression factor

    Subjects wearing orthokeratology lenses of increased compression factor about 1.50-1.75D.

    Device: Orthokeratology

Interventions

  • DeviceOrthokeratology

    Also known as: ortho-k

06

What researchers measure

Primary outcomes

  1. Axial length

    axial progression of the eyeball

    Time frame: every 6 monthly in 2 years

Secondary outcomes

  1. Ocular aberration measured by Complete Ophthalmic Analysis System (COAS) aberrometer

    ocular aberration measured by Complete Ophthalmic Analysis System (COAS) aberrometer

    Time frame: every 6 monthly in 2 years

  2. Corneal biomechanics (corneal response using ocular response)

    corneal response using ocular response

    Time frame: every 6 monthly in 2 years

  3. Accommodation lag measured by Complete Ophthalmic Analysis System (COAS) aberrometer

    accommodation lag measured by Complete Ophthalmic Analysis System (COAS) aberrometer using different accommodation targets

    Time frame: every 6 monthly in 2 years

  4. Choroidal thickness captured by Optical Coherent Tomographer (OCT)

    choroidal thickness captured by Optical Coherent Tomographer (OCT) and measured using a customized software

    Time frame: every 6 monthly in 2 years

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Study locations

1 site
  • School of Optometry, The Hong KOng Polytechnic University
    Hong Kong, China
08

References and documents

Publications

  • 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. PubMed 22150587 ↗
  • 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. PubMed 15875367 ↗
  • 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. PubMed 22969068 ↗
  • 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. PubMed 24003088 ↗
  • 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. PubMed 18434845 ↗
  • 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. PubMed 22495031 ↗
  • 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. PubMed 18055781 ↗
  • 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. PubMed 18426426 ↗
  • 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. PubMed 32420450 ↗
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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jul 30, 2020, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT02643342
Lead sponsor
The Hong Kong Polytechnic University
Collaborators
Menicon Co., Ltd., Queensland University of Technology, Aston University
Responsible party
Pauline Cho (Professor, The Hong Kong Polytechnic University) — Principal investigator
First posted
Dec 31, 2015
Start date
Jun 18, 2016
Primary completion
Aug 3, 2019
Completion
Aug 3, 2019
Last update
Jul 30, 2020

Study contacts

Pauline Cho, PhD
principal investigator · The Hong Kong Polytechnic University

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Feb 2020. You cannot join it, but the record below documents what was studied.

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