Peripheral Optics in Myopia and Orthokeratology

Study Overview
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Brief Summary
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The primary objective of the current study is to investigate changes in peripheral refraction and aberration in children wearing orthokeratology lenses and single-vision spectacles.

Detailed Description
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Apart from being effective in reducing low to moderate myopia, orthokeratology has been shown to have potential in retarding myopic progression. The central cornea is flattened and peripheral optics altered in orthokeratology and it has been suggested that orthokeratology slows myopic progression through the alteration of peripheral optics. The aim of the current study is to investigate the changes in peripheral refraction and aberration in children wearing orthokeratology (study group) and single-vision spectacles (control group).

Official Title
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Peripheral Refraction and Aberration in Myopic Progression and Myopic Control

Conditions
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Myopia

Intervention / Treatment
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* Device: Orthokeratology lenses
* Device: Spectacles


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Myopia (refractive sphere): > 0.50D and ≤ 6.00D Astigmatism: with-the-rule astigmatism (axes 180 +/- 30) ≤ 1.50D; astigmatism of other axes ≤ 0.50D Spherical equivalent (SE): > 0.50D and ≤ 6.75D (myopia) Best corrected monocular visual acuity: equal to or better than 6/7.5 in Snellen scale 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 myopic control treatment (e.g. refractive therapy or progressive 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)

Ages Eligible for Study
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Minimum Age: 6 Years
Maximum Age: 9 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Orthokeratology<br>Myopic children wearing orthokeratology at night will be the study group | Device: Orthokeratology lenses<br>* Nightly use of orthokeratology lenses to correct the refractive errors<br>* Other names: Menicon Z Night Lens 2 Toric;|
| Other: Others<br>Myopic children wearing single-vision spectacles in the daytime will serve as control group | Device: Spectacles<br>* Daily use of single vision lenses to correct refractive errors<br>* Other names: Eyeglasses;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in cycloplegic off-axial auto-refraction, aberration and eyeball length |  | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Children, Peripheral refraction, Aberration, Eyeball length, Myopic control, Myopia, Corneal reshaping, Orthokeratology