Myopic Control for High Myopes Using Orthokeratology

Not Applicable

Completed

• Conditions: Myopia
• Interventions: Device: Orthokeratology lenses; Device: Single-vision spectacle lenses

• Registration Number: NCT00977236
• Lead Sponsor: The Hong Kong Polytechnic University

Brief Summary

The purpose of this study is to evaluate and compare the eyeball elongation in high myopic children using partial correction orthokeratology and single-vision spectacles.

Detailed Description

Orthokeratology (ortho-k) has been shown to have strong potential for retardation of myopic progression in low myopes. To date, clinical experience has shown the technique to be less effective in achieving full myopic reduction in high myopes. Would myopic control be possible for high myopes undergoing partial correction ortho-k treatment?

A randomized, longitudinal study is designed to investigate the efficacy of partial correction ortho-k in retardation of myopic progression in high myopic children. Eye growth in terms of axial length elongation in children wearing ortho-k and over-spectacles (to correct residual refractive errors) (study group) and those wearing single-vision spectacles (control group) will be evaluated and compared.

Study Timeline

• Study Start: 2008-07
• Study First Submitted: 2009-09-14
• Study First Submitted QC: 2009-09-14
• Study First Posted: 2009-09-15
• Primary Completion: 2011-12
• Study Completion: 2012-12
• Status Verified: 2013-07
• Last Update Submitted: 2013-07-11
• Last Update Posted: 2013-07-12

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 52

Inclusion Criteria

• Myopia (refractive sphere): > 5.75D
• Astigmatism: < ½ of myopia; with-the-rule astigmatism (axes 180 +/- 30) ≤1.25D; astigmatism of other axes ≤ 0.50D
• Spherical equivalent (SE): > 5.75D
• 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 for randomization
• Availability for follow-up for at least 2 years

Exclusion Criteria

• Strabismus at distance or near
• Contraindication for contact lens wear and orthokeratology (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)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Orthokeratology lenses	Orthokeratology lenses	Children wearing orthokeratology at night for partial correction and spectacles at daytime for residual refractive error will be study group
Single-vision spectacle lenses	Single-vision spectacle lenses	Children wearing single-vision spectacles in the daytime for correcting the refractive error will serve as control group

Primary Outcome Measures

Name	Time	Method
Determine the change in cycloplegic axial length in the study and control groups	2 years

Secondary Outcome Measures

Name	Time	Method
Determine the incidence of adverse effects in cornea, the palpebral, bulbar and tarsal conjunctiva in the study and the control groups	2 years
Rate of regression during the daytime	2 years

Trial Locations

Locations (1)

School of Optometry, The Hong Kong Polytechnic University; 🇨🇳 Hong Kong SAR, China