NCT03881358

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.

Trial Health

43
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
66

participants targeted

Target at P50-P75 for not_applicable

Timeline
Completed

Started Aug 2018

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

August 4, 2018

Completed
7 months until next milestone

First Submitted

Initial submission to the registry

February 21, 2019

Completed
26 days until next milestone

First Posted

Study publicly available on registry

March 19, 2019

Completed
4.6 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

November 1, 2023

Completed
2 months until next milestone

Study Completion

Last participant's last visit for all outcomes

January 1, 2024

Completed
Last Updated

February 16, 2021

Status Verified

February 1, 2021

Enrollment Period

5.2 years

First QC Date

February 21, 2019

Last Update Submit

February 14, 2021

Conditions

MyopiaHigh Myopia

Keywords

Myopia controlOrthokeratologyChildren

Outcome Measures

Primary Outcomes (1)

  • Change in axial length elongation over 24 months.

    To determine the change in axial length measured at baseline and two years after lens wear using IOLMaster

    2 years

Secondary Outcomes (3)

  • First fit success rate of a newly designed ortho-k lens for high myopic children

    1 month

  • Quality of life (questionnaire)

    3 months

  • Ocular aberration

    2 years

Study Arms (2)

ortho-k lenses and thinner spectacles

ACTIVE COMPARATOR

participants using conventionally designed ortho-k lenses (target for 4.00D) and thinner spectacles during day time

Device: ortho-k lenses and thinner spectacles

newly designed ortho-k lenses

EXPERIMENTAL

participants using newly designed ortho-k lenses for high myopia (target for full correction)

Device: newly designed ortho-k lenses

Interventions

ortho-k lenses and thinner spectaclesDEVICE

Conventinally designed (Emerald) ortho-k lenses (target for -4.00D) and thinner specs during day time

ortho-k lenses and thinner spectacles
newly designed ortho-k lensesDEVICE

Newly designed (Topaz) ortho-k lenses for high myopia (target for full correction)

newly designed ortho-k lenses

Eligibility Criteria

Age7 Years - 13 Years
Sexall
Healthy VolunteersYes
Age GroupsChild (0-17)

You may qualify if:

  • 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

You may not qualify if:

  • 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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

School of Optometry, The Hong Kong Polytechnic University

Kowloon, Hong Kong

RECRUITING

Related Publications (12)

  • Lam CS, Goldschmidt E, Edwards MH. Prevalence of myopia in local and international schools in Hong Kong. Optom Vis Sci. 2004 May;81(5):317-22. doi: 10.1097/01.opx.0000134905.98403.18.

    PMID: 15181356BACKGROUND

  • Walline JJ, Lindsley K, Vedula SS, Cotter SA, Mutti DO, Twelker JD. Interventions to slow progression of myopia in children. Cochrane Database Syst Rev. 2011 Dec 7;(12):CD004916. doi: 10.1002/14651858.CD004916.pub3.

    PMID: 22161388BACKGROUND

  • Kakita T, Hiraoka T, Oshika T. Influence of overnight orthokeratology on axial elongation in childhood myopia. Invest Ophthalmol Vis Sci. 2011 Apr 6;52(5):2170-4. doi: 10.1167/iovs.10-5485.

    PMID: 21212181BACKGROUND

  • 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: 15875367BACKGROUND

  • Swarbrick HA. Orthokeratology review and update. Clin Exp Optom. 2006 May;89(3):124-43. doi: 10.1111/j.1444-0938.2006.00044.x.

    PMID: 16637967BACKGROUND

  • 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.

    PMID: 19416935BACKGROUND

  • Charm J, Cho P. High myopia-partial reduction orthokeratology (HM-PRO): study design. Cont Lens Anterior Eye. 2013 Aug;36(4):164-70. doi: 10.1016/j.clae.2013.02.012. Epub 2013 Mar 18.

    PMID: 23518209BACKGROUND

  • Cho P, Cheung SW, Edwards MH. Practice of orthokeratology by a group of contact lens practitioners in Hong Kong. Part 2: orthokeratology lenses. Clin Exp Optom. 2003 Jan;86(1):42-6. doi: 10.1111/j.1444-0938.2003.tb03056.x.

    PMID: 12568650BACKGROUND

  • Lee TT, Cho P. Relative peripheral refraction in children: twelve-month changes in eyes with different ametropias. Ophthalmic Physiol Opt. 2013 May;33(3):283-93. doi: 10.1111/opo.12057.

    PMID: 23662961BACKGROUND

  • Atchison DA, Li SM, Li H, Li SY, Liu LR, Kang MT, Meng B, Sun YY, Zhan SY, Mitchell P, Wang N. Relative Peripheral Hyperopia Does Not Predict Development and Progression of Myopia in Children. Invest Ophthalmol Vis Sci. 2015 Sep 1;56(10):6162-70. doi: 10.1167/iovs.15-17200.

    PMID: 26397463BACKGROUND

  • Hiraoka T, Matsumoto Y, Okamoto F, Yamaguchi T, Hirohara Y, Mihashi T, Oshika T. Corneal higher-order aberrations induced by overnight orthokeratology. Am J Ophthalmol. 2005 Mar;139(3):429-36. doi: 10.1016/j.ajo.2004.10.006.

    PMID: 15767050BACKGROUND

  • 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: 18434845BACKGROUND

MeSH Terms

Conditions

Myopia

Condition Hierarchy (Ancestors)

Refractive ErrorsEye Diseases

Study Officials

  • Pauline Cho, PhD

    The Hong Kong Polytechnic University

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Pauline Cho, PhD

CONTACT

(+852) 2766 6100pauline.cho@polyu.edu.hk

Yajing Yang, BSc

CONTACT

(+852) 6486 2435grace.yj.yang@connect.polyu.hk

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

February 21, 2019

First Posted

March 19, 2019

Study Start

August 4, 2018

Primary Completion

November 1, 2023

Study Completion

January 1, 2024

Last Updated

February 16, 2021

Record last verified: 2021-02

Locations

HK(1)