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

NCT02643342 | Completed

• 1 other identifier: HSEARS20150909002
• Study Type: interventional
• Target: 99
• Locations: 1 country
• Sites: 1

Brief 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.

Conditions

Myopic Progression

Keywords

myopia control; orthokeratology

Outcome Measures

Primary Outcomes (1)

• Axial length

  axial progression of the eyeball

  every 6 monthly in 2 years

Secondary Outcomes (4)

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

  every 6 monthly in 2 years

• Corneal biomechanics (corneal response using ocular response)

  every 6 monthly in 2 years

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

  every 6 monthly in 2 years

• Choroidal thickness captured by Optical Coherent Tomographer (OCT)

  every 6 monthly in 2 years

Study Arms (3)

Single-vision glasses

NO INTERVENTION

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

Orthokeratology with normal compression factor

SHAM COMPARATOR

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

Device: Orthokeratology

Orthokeratology with increased compression factor

ACTIVE COMPARATOR

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

Device: Orthokeratology

Interventions

Orthokeratology DEVICE

Also known as: ortho-k

Orthokeratology with increased compression factor; Orthokeratology with normal compression factor

Eligibility Criteria

• Age: 6 Years - 10 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• The Hong Kong Polytechnic University: lead
• Menicon Co., Ltd.: collaborator
• Queensland University of Technology: collaborator
• Aston University: collaborator

Study Sites (1)

School of Optometry, The Hong KOng Polytechnic University

Hong Kong, China

Location

Related Publications (9)

• 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.

  PMID: 22150587 BACKGROUND

• 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.

  PMID: 15875367 BACKGROUND

• 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.

  PMID: 22969068 BACKGROUND

• 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.

  PMID: 24003088 BACKGROUND

• 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.

  PMID: 18434845 BACKGROUND

• 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.

  PMID: 22495031 BACKGROUND

• 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.

  PMID: 18055781 BACKGROUND

• 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.

  PMID: 18426426 BACKGROUND

• 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.

  PMID: 32420450 DERIVED

Study Officials

• Pauline Cho, PhD

  The Hong Kong Polytechnic University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: December 28, 2015
• First Posted: December 31, 2015
• Study Start: June 18, 2016
• Primary Completion: August 3, 2019
• Study Completion: August 3, 2019
• Last Updated: July 30, 2020

Record last verified: 2020-02

Locations

CN (1)