Monthly Replacement Orthokeratology for Myopia Control in Existing Lens Wearers

Study Overview
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Brief Summary
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The two-year prospective study aims at investigating the benefits of frequent replacement (monthly) orthokeratology lenses in myopia control in terms of effectiveness in control and prevention of ocular complications. The secondary objective will be investigating the use of weekly protein removal system in monthly replacement modality orthokeratology lenses on surface deposit.

Detailed Description
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This is a two-year randomized trial. Existing orthokeratology lens wearers (aged 8-13 years), who have completed a 2-year myopia control using orthokeratology, will be recruited and monitored for another two years. Eligible subjects will be randomly assigned to monthly or yearly replacement modality. Axial elongation and ocular conditions will be compared between the monthly and yearly replacement groups. Subjects on monthly replacement lenses will be randomly assigned to normal cleaning and intensive cleaning groups. Subjects in normal cleaning group will be provided with complimentary contact lenses solutions for daily cleaning and disinfection. In addition to the daily procedures for lens case, subjects in the intensive cleaning group will be required to perform weekly protein removal. All subjects on yearly replacement lenses will be required to performed intensive cleaning such that they will follow normal daily cleaning and disinfection as well as weekly protein removal.

Official Title
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Accrued Effect of Orthokeratology for Myopia Control in Children and the Effectiveness of Myopia Control Using an Innovative Orthokeratology Modality. Experiment 1. Effect in Existing Ortho-k Wearers

Conditions
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Myopic Progression

Intervention / Treatment
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* Device: orthokeratology
* Device: Menicon Progent A+B


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 8-15 years Have completed a two-year myopia control study using ortho-k Normal ocular and general condition and not on medication which may contraindicate ortho-k lens wear Pre-ortho-k refractive sphere between -0.75 to -4.00 DS, refractive cylinder ≤ -1.50 DC and anisometropia ≤ -1.00 D Best correctable vision better than 0.08 logMAR in the worse eye Normal binocular function and accommodative status Exclusion Criteria: Strabismus at distance or near Contraindication for ortho-k lens wear Prior history of ocular surgery, trauma, or chronic ocular disease Systemic or ocular conditions that may interfere refractive development Systemic or ocular conditions that may interfere tear quality and contact lens wear Poor response to the use of study lenses Poor compliance to test procedures Poor compliance to the use of ortho-k lenses (e.g. use of solution, use of lenses) Poor compliance to follow-up schedule

Ages Eligible for Study
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Minimum Age: 8 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
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: All subjects will be randomly assigned to use monthly or yearly replacement orthokeratology for a period of 24 months. Subjects on monthly replacement modality will be randomly assigned to normal cleaning and intensive cleaning groups. Subjects in normal cleaning group will be provided with complimentary contact lenses solutions for daily cleaning and disinfection. In addition to the daily procedures for lens case, subjects in the intensive cleaning group will be required to perform weekly protein removal. Intensive cleaning is indicated for yearly replacement modality, thus, no randomization of care procedures in this group.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Monthly replacement orthokeratology without protein removal<br>Subjects will be required to perform daily cleaning for the monthly replacement orthokeratology lenses | Device: orthokeratology<br>* Nightly wear of orthokeratology lenses to correct vision in the daytime<br>* Other names: corneal reshaping therapy;|
| Active Comparator: Monthly replacement lenses with weekly protein removal<br>Subjects will be required to perform both daily cleaning and weekly protein removal for the monthly replacement orthokeratology lenses | Device: orthokeratology<br>* Nightly wear of orthokeratology lenses to correct vision in the daytime<br>* Other names: corneal reshaping therapy;Device: Menicon Progent A+B<br>* Menicon Progent A+B is a commercially available protein remover for rigid lenses. It has received FDA clearance and been launched in Hong Kong for over a decade. The product contains two separate sterile solutions, one with sodium hypochlorite and the other with potassium bromide. By mixing the two solutions in a special vial, it can clean and remove protein deposits on the lenses. Parents of subjects assigned to use weekly protein remover will be required to soak the cleansed lenses in the solution mixture for not more than 30 mins every week. All lenses must be rinsed thoroughly with saline and cleansed with daily cleaner again before daily disinfection.<br>* Other names: Menicon Progent Protein Remover for Rigid Gas Permeable Contact Lenses;|
| Active Comparator: Yearly replacement lenses with weekly protein removal<br>Subjects will be prescribed with orthokeratology lenses which will be replaced at least every 12 months during the study period. They will be required to perform both daily cleaning and weekly protein removal for their lenses. | Device: orthokeratology<br>* Nightly wear of orthokeratology lenses to correct vision in the daytime<br>* Other names: corneal reshaping therapy;Device: Menicon Progent A+B<br>* Menicon Progent A+B is a commercially available protein remover for rigid lenses. It has received FDA clearance and been launched in Hong Kong for over a decade. The product contains two separate sterile solutions, one with sodium hypochlorite and the other with potassium bromide. By mixing the two solutions in a special vial, it can clean and remove protein deposits on the lenses. Parents of subjects assigned to use weekly protein remover will be required to soak the cleansed lenses in the solution mixture for not more than 30 mins every week. All lenses must be rinsed thoroughly with saline and cleansed with daily cleaner again before daily disinfection.<br>* Other names: Menicon Progent Protein Remover for Rigid Gas Permeable Contact Lenses;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Axial elongation in 2 years | Cycloplegic examination of the eyeball length using IOLMaster every 6 monthly | 2 years | 
| Back Surface Lens Deposits | Surface deposits will be graded using a 4-point scale: 0=no deposit; 1=mild; 2=moderate; 3=severe | Every month up to 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with serious adverse effects in 2 years | Number of subjects with serious adverse effects of the cornea, the palpebral, bulbar and tarsal conjunctiva in 2 years | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Myopia progression, Orthokeratology, Replacement modality, Surface deposits