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

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

Detailed Description
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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.

Official Title
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Discontinuation of Orthokeratology on Eyeball Elongation (DOEE) Study. (2) Discontinuation of Lens Wear in New Ortho-k Children

Conditions
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Myopia

Intervention / Treatment
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* Device: single-vision glasses
* Device: ortho-k lenses


Participation Criteria
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Eligibility Criteria
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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)

Ages Eligible for Study
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Minimum Age: 6 Years
Maximum Age: 15 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
Intervention Model: Single Group Assignment
Interventional Model Description: All subjects were prescribed with a pair of glasses for seven months and switched to orthokeratology for another seven months
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: ortho-k lenses<br>Children were switched to wear ortho-k lenses for 7 months after wearing single-vision glasses for 7 months | Device: single-vision glasses<br>* Daily wear of glasses to correct vision in the first seven months of the study<br>* Other names: CR-39 lenses;Device: ortho-k lenses<br>* Nightly wear of lenses to correct vision in day time in the second seven months of the study<br>* Other names: Menicon Z Night Toric lenses;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Axial Elongation in the Two Study Phases | Axial elongation in children during the two study phases. Phase I: 7 months wearing single-vision spectacles. Phase II: 7 months wearing orthokeratology | 14 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Serious Adverse Effects | Number of subjects with serious adverse effects of the cornea, the palpebral, bulbar and tarsal conjunctiva | 14 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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children, corneal reshaping, myopia, myopia progression, orthokeratology