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Orthokeratology for High Myopia (OHM) Study

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ClinicalTrials.gov Identifier: NCT03881358
Recruitment Status : Recruiting
First Posted : March 19, 2019
Last Update Posted : March 19, 2019
Sponsor:
Collaborators:
Queensland University of Technology
Aston University
Information provided by (Responsible Party):
Pauline Cho, The Hong Kong Polytechnic University

Brief Summary:
This project aims to investigate/examine high myopic subjects on full correction ortho-k (using Topaz ortho-k lenses for high myopia) compared to subjects undergoing partial reduction ortho-k and their relationship with myopia and myopic progression.

Condition or disease Intervention/treatment Phase
Myopia High Myopia Device: ortho-k lenses and thinner spectacles Device: newly designed ortho-k lenses Not Applicable

Detailed Description:

For many years, commercially-available ortho-k lenses aim to reduce low - moderate myopia. Attempts to use these lenses for reduction of high myopia have been shown to give rise to complications such as corneal staining and lens decentration. Thus, practitioners may choose a more conservative way for high myopic children, that is, offering partial reduction ortho-k. Partial reduction ortho-k is target for 4.00-5.00D reduction and the residual refractive errors will be corrected with single vision spectacles to allow good visual acuity in the daytime. Partial reduction ortho-k has been shown to slow axial elongation in high myopic children, however, the main disadvantage is that the children have to wear spectacles in the daytime to correct residual refraction.

Euclid has recently designed a new lens, Euclid's Topaz, for high myopic children. It is currently commercially available to correct myopia for up to 10 D. However, evidence of its effectiveness for visual correction and slowing AL growth is lacking. While numerous studies have shown that orthokeratology is an effective clinical treatment to slow axial eye growth in children, the exact mechanism underlying this reduction in myopia progression associated with orthokeratology remains unclear.


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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 66 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Orthokeratology for High Myopia (OHM) Study
Actual Study Start Date : August 4, 2018
Estimated Primary Completion Date : August 2021
Estimated Study Completion Date : October 2021

Resource links provided by the National Library of Medicine


Arm Intervention/treatment
Active Comparator: ortho-k lenses and thinner spectacles
participants using conventionally designed ortho-k lenses (target for 4.00D) and thinner spectacles during day time
Device: ortho-k lenses and thinner spectacles
Conventinally designed (Emerald) ortho-k lenses (target for -4.00D) and thinner specs during day time

Experimental: newly designed ortho-k lenses
participants using newly designed ortho-k lenses for high myopia (target for full correction)
Device: newly designed ortho-k lenses
Newly designed (Topaz) ortho-k lenses for high myopia (target for full correction)




Primary Outcome Measures :
  1. Change in axial length elongation over 24 months. [ Time Frame: 2 years ]
    To determine the change in axial length measured at baseline and two years after lens wear using IOLMaster


Secondary Outcome Measures :
  1. First fit success rate of a newly designed ortho-k lens for high myopic children [ Time Frame: 1 month ]
    The success rate in using the first pair of lenses to achieve target refractive correction will be determined

  2. Quality of life (questionnaire) [ Time Frame: 3 months ]
    Quality of life will be determined by questionnaires (using revised PREP1 in traditional Chinese version) before and after ortho-k in the two groups of subjects

  3. Ocular aberration [ Time Frame: 2 years ]
    Ocular aberration will be measured by Complete Ophthalmic Analysis System (COAS) aberrometer



Information from the National Library of Medicine

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Ages Eligible for Study:   7 Years to 13 Years   (Child)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Myopia: at least 5.00D in one eye or in both eyes
  • Astigmatism: ≤1.50D; with-the-rule astigmatism (axes 180 ± 30) ≤1.25D; astigmatism of other axes ≤0.50D in both eyes
  • Anisometropia: not be more than 1.00D in the former and not more than 2.00D in the latter.
  • Best-corrected Monocular Snellen visual acuity 6/7.5 or better

Exclusion Criteria:

  • Strabismus at distance or near
  • Previous experience in contact lens wear or myopia control treatment (e.g. refractive therapy or progressive spectacles)
  • Contraindication for contact lens wear and orthokeratology (e.g. limbus to limbus corneal cylinder and dislocated corneal apex)
  • Previous history of ocular surgery, trauma, or chronic ocular disease
  • Concurrent use of medications that may affect tear quality or contact lens wear
  • Systemic or ocular conditions that may affect tear quality or contact lens wear (e.g allergy and concurrent medication) or that may affect refractive development (e.g Down syndrome, ptosis)
  • Poor compliance to tests (e.g poor fixation in noncontact tonometry or intolerance of lens wear)
  • Not willing to comply with the allocated treatment, use and care of lenses and follow-up schedule

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03881358


Contacts
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Contact: Pauline Cho, PhD (+852) 2766 6100 pauline.cho@polyu.edu.hk
Contact: Yajing Yang, BSc (+852) 6486 2435 grace.yj.yang@connect.polyu.hk

Locations
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Hong Kong
School of Optometry, The Hong Kong Polytechnic University Recruiting
Kowloon, Hong Kong
Contact: Pauline Cho, PhD    (+852)2766 6100    pauline.cho@polyu.edu.hk   
Contact: Yajing Yang, BSc    (+852)6486 2435    grace.yj.yang@connect.polyu.hk   
Principal Investigator: Pauline Cho, PhD         
Sponsors and Collaborators
The Hong Kong Polytechnic University
Queensland University of Technology
Aston University
Investigators
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Principal Investigator: Pauline Cho, PhD The Hong Kong Polytechnic University

Publications:

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Responsible Party: Pauline Cho, Professor, The Hong Kong Polytechnic University
ClinicalTrials.gov Identifier: NCT03881358     History of Changes
Other Study ID Numbers: HSEARS20180322002
First Posted: March 19, 2019    Key Record Dates
Last Update Posted: March 19, 2019
Last Verified: March 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by Pauline Cho, The Hong Kong Polytechnic University:
Myopia control
Orthokeratology
Children

Additional relevant MeSH terms:
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Myopia
Refractive Errors
Eye Diseases