The Safety and Effectiveness of Breath-O Lenses

Study Overview
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Brief Summary
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In Hong Kong, approximately 80% of children are myopic by the end of childhood. There is intense interest currently in the potential role of peripheral defocus as a clinical treatment to slow myopia progression. One of the most successful treatments for myopia is orthokeratology. Currently, Breath-O correct lenses are new designed ready-made orthokeratology lenses. This study is to evaluate the safety of wearing this new orthokeratology lens and the effectiveness of clinical performance in young adult.

Detailed Description
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Short-sightedness (myopia) is the most common refractive error in the world. In Hong Kong, approximately 80% of children are myopic by the end of childhood. Current treatment strategies to control (i.e. slow) myopia progression in children are primarily designed to harness the natural emmetropization process, in which visual feedback from retinal image clarity regulates the rate of eye growth. There is intense interest currently in the potential role of peripheral defocus as a clinical treatment to slow myopia progression, not least since this approach permits clear central vision. One of the most successful treatments for myopia is orthokeratology, which is a therapy of using custom-made rigid gas permeable contact lens. The special design of this contact lens can reshape the corneal profile to minimize the central refractive error while producing beneficial peripheral defocus. Currently, Breath-O correct lenses are new designed ready-made orthokeratology lenses which are made of new material with more elasticity as compared traditional lens material. This study is to evaluate the safety of wearing this new orthokeratology lens and the effectiveness of clinical performance in young adult.

Official Title
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The Safety and Effectiveness of Clinical Performance of Breath-O Correct Orthokeratology Lenses

Conditions
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Myopia, Safety Issues

Intervention / Treatment
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* Other: Breath-O-Correct Lens


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Refractive error: Spherical: normally -1.00D to -4.00D (maximum up to -5.00D); Cylindrical: normally half of Sph (against-the-rule Astigmatism.: lower than -0.75D) (maximum up to -1.50D) Best corrected Visual acuity: monocular ETDRS 0.0 or better Ocular health: No ocular abnormality, no contra-indications for overnight orthokeratology lens wear, no refractive surgery General health: No systemic diseases Requirement: No history of orthokeratology lens wearing. Agree to participate in this study and willing to wear the orthokeratology lenses overnight in accordance with the instructions given and to come back for follow up within the study period

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 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: Randomized control trial
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Treatment<br>Wearing the orthokeratology lenses for 3 months | Other: Breath-O-Correct Lens<br>* Breath-O correct lenses are new designed ready-made orthokeratology lenses which are made of new material with more elasticity as compared traditional lens material<br>|
| No Intervention: Control<br>Not wearing any contact lenses | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor | measured by ocular response analyser | Baseline, 1st Month, 3rd Month | 
| Corneal Endothelial Health in Terms of Endothelial Cell Density | measured by specular microscope | Baseline, 1st Month, 3rd Month | 
| Corneal Endothelial Health in Terms of Percentage of Variation in Cell Size | measured by specular microscope | Baseline, 1st Month, 3rd Month | 
| Anterior Ocular Health in Terms of Limbal and Bulbar Redness | measured by OCULUS Keratograph® 5M and graded by JENVIS redness grading system It is a scale of 0 to 4, the higher the score, the more redness the ocular surface manifests | Baseline, 1st Month, 3rd Month | 
| Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT) | measured by OCULUS Keratograph® 5M | Baseline, 1st Month, 3rd Month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Best Corrected Visual Acuity in Terms of High and Low Contrast | The best corrected visual acuity was measured in LogMAR (Snellen 20/20 vision = 0.00 in LogMAR ; each readable letter add -0.02 to the score, the smaller the number i.e. more negative, the better visual acuity) | Baseline, 1st Month and the 3rd Month | 
| Reduction of the Refractive Power After Wearing the Breath-O-correct Lens | Refractive errors were determined by subjective refraction for treatment group (Breath-O correct lens wearer), the outcome was represented as mean spherical equivalent refraction with unit in diopter (SER, = 1/2 Cylindrical power + spherical power) | Baseline, 1st Week, 1st Month, 3rd Month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Myopia, Orthokeratology