Retardation of Myopia in Orthokeratology

The Hong Kong Polytechnic University102 enrolled

Overview

The primary aim of this study is to evaluate and compare the eyeball elongation in children wearing orthokeratology lenses and single-vision spectacles.

Prevalence of myopia is high in Asian countries like Hong Kong. Orthokeratology has shown potential in slowing myopic progression but the efficacy is yet to be confirmed by a randomized clinical trial (RCT). The current RCT aims at studying the efficacy of orthokeratology in retardation of myopic progression by comparing the eye growth in terms of axial length elongation in children wearing orthokeratology lenses (study group) and those wearing single-vision spectacles (control group).

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

102

Conditions

Myopia

Interventions

orthokeratology lensesDEVICE

Nightly use of orthokeratology to correct the refractive error for a period of two years

single-vision spectacle lensesDEVICE

Daily use of spectacles to correct the refractive error for a period of two years

Eligibility

Sex: ALLMin age: 6 YearsMax age: 10 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Myopia (refractive sphere): \> 0.50D and ≤ 4.00D * Astigmatism: \< ½ of myopia; with-the-rule astigmatism (axes 180 +/- 30) ≤1.25D; astigmatism of other axes ≤ 0.50D * Spherical equivalent (SE): \> 0.75D and ≤ 4.50D * 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 * Willingness to wear contact lenses or spectacles on a daily basis * 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 * Prior experience with the use of rigid lenses (including orthokeratology) * Prior experience with myopia control treatment (e.g. refractive therapy or progressive add spectacles) * 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)

Locations (1)

School of Optometry, The Hong Kong Polytechnic University

Hong Kong, Hong Kong, China

Outcomes

Primary Outcomes

Axial Elongation in the Study and Control Subjects Who Completed the Two Years Study

Axial elongation was determined by the change in axial length of the eyeball before and after treatment period. Axial length was measured by the IOLMaster (Zeiss Humphrey, Dublin, CA) 30 minutes after cycloplegia. The measurement of the axial length followed the procedures as recommended by the manufacturer.

Time frame: 2 years

Secondary Outcomes

Determine the Incidence of Adverse Effects in Cornea, the Palpebral, Bulbar and Tarsal Conjunctiva in the Study and the Control Groups

Time frame: 2 years

Determine Changes in Other Ocular Parameters (e.g. Corneal Biomechanics and Aberration) Associated With Orthokeratology Lens Wear

Time frame: 2 years

Data from ClinicalTrials.gov

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