Discontinuation of Lens Wear in New Ortho-k Children (DOEE2)

The recruitment status of this study is unknown because the information has not been verified recently.
Verified June 2011 by The Hong Kong Polytechnic University.
Recruitment status was  Recruiting
Sponsor:
Collaborator:
Menicon Co., Ltd.
Information provided by:
The Hong Kong Polytechnic University
ClinicalTrials.gov Identifier:
NCT01236755
First received: November 8, 2010
Last updated: June 23, 2011
Last verified: June 2011
  Purpose

This study aims at investigating the efficacy of myopic control using ortho-k in younger and older children.


Condition Intervention
Myopia
Procedure: Switching of single-vision spectacles to orthokeratology

Study Type: Interventional
Study Design: Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Discontinuation of Orthokeratology on Eyeball Elongation (DOEE) Study. (2) Discontinuation of Lens Wear in New Ortho-k Children

Resource links provided by NLM:


Further study details as provided by The Hong Kong Polytechnic University:

Primary Outcome Measures:
  • Axial length [ Time Frame: 14 months ] [ Designated as safety issue: No ]
    To determine and compare the rate of axial elongation in spectacle lens and contact lens wear periods


Secondary Outcome Measures:
  • Incidence of adverse effects [ Time Frame: 14 months ] [ Designated as safety issue: Yes ]
    To determine the incidence of adverse effects of the cornea, the palpebral, bulbar and tarsal conjunctiva


Estimated Enrollment: 90
Study Start Date: October 2010
Estimated Study Completion Date: March 2013
Estimated Primary Completion Date: October 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Switching to ortho-k
Children wearing single-vision spectacles will be switched to ortho-k for correction of refractive errors
Procedure: Switching of single-vision spectacles to orthokeratology
Switching from single-vision spectacles to orthokeratology to correct the refractive errors

Detailed Description:

Children wearing ortho-k have been shown to have slower rate of myopic progression than those wearing single-vision spectacles (Cho et al. 2005) or soft lenses (Walline et al. 2009). Younger myopic children (aged 6-10 years old) may have the faster increase in myopia than old myopic children (aged 11-15 years old), i.e. the rate of myopic progression may be different in different age groups and in children with different refractive status (Edwards 1999; Fan et al. 2004; Cheng et al. 2007). Although the refractive correction with ortho-k has been well documented, it is unknown whether the efficiency and reversibility of ortho-k for myopic reduction as well as myopic control are similar in children of different age and refractive groups.

In this 14-month study, the eyeball length in 45 younger (6-10 years old) and 45 older (11-15 years old) myopic children before and after ortho-k will be evaluated. Eyeball elongation will be determined for the first 7 months when single-vision glasses will be prescribed (Phase I) and the next 7 months when ortho-k will be prescribed (Phase I). Rate of myopic progression will be determined and compared between the two groups of children in the two phases.

  Eligibility

Ages Eligible for Study:   6 Years to 15 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Age: between 6 to 15 years old
  • Myopia: between 1.50D and 4.50D in at least one eye
  • Spherical equivalent (SE): between -1.00D to -4.50D in both eyes
  • Astigmatism: ≤ 3.00D of axes 180 +/- 30 or ≤ 1.00D of other axes; and the amount is less than refractive sphere
  • Anisometropia: ≤ 1.50D in both refractive sphere, refractive cylinder and SE
  • Best corrected monocular visual acuity: equal to or better than 0.10 in logMAR scale in both eyes
  • Willingness to wear contact lenses or spectacles on a daily basis
  • Can obtain good ortho-k results with the study lenses
  • Availability for follow-up for at least 14 months

Exclusion Criteria:

  • Strabismus at distance or near
  • Contraindication for contact lens wear and ortho-k (e.g. limbus to limbus corneal cylinder and dislocated corneal apex
  • Systemic or ocular conditions which may affect contact lens wear (e.g. allergy and medication)
  • Systemic or ocular conditions which may affect refractive development (e.g. Down syndrome, ptosis)
  • Prior experience with the use of rigid lenses (including ortho-k)
  • Prior experience with myopia control treatment (e.g. refractive therapy or progressive spectacles)
  • Non-compliance to the follow up schedule
  • Non-compliance to the use of the prescribed optical correction
  • Poor ocular response to ortho-k lens wear
  • Significant residual refractive error after ortho-k treatment resulting in poor unaided vision (worse than 0.18 in logMAR scale)
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT01236755

Contacts
Contact: Pauline Cho, PhD (852) 2766 6100 sopaulin@inet.polyu.edu.hk
Contact: Sin Wan Cheung, MPhil (852) 2766 4462 sopeggy@inet.polyu.edu.hk

Locations
China
School of Optometry, The Hong Kong Polytechnic University Recruiting
Hong Kong SAR, China
Contact: Pauline Cho, PhD     (852) 2766 6100     sopaulin@inet.polyu.edu.hk    
Contact: Sin Wan Cheung, MPhil     (852) 2766 4662     sopeggy@inet.polyu.edu.hk    
Principal Investigator: Pauline Cho, PhD            
Sponsors and Collaborators
The Hong Kong Polytechnic University
Menicon Co., Ltd.
Investigators
Principal Investigator: Pauline Cho, PhD The Hong Kong Polytechnic University