Effects of Different Designs of Orthokeratology Lens on Myopia Control and Visual Quality

Study Overview
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Brief Summary
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This study was aimed to evaluate the effects of different Orthokeratology，including the size of central optical zone and the height of peripheral reverse curve, on myopia control and visual quality.

Detailed Description
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This study was aimed to evaluate the effects of different Orthokeratology on myopia control and visual quality. The different optical zone of Orthokeratology lens was divided into 4 groups, ranged from 5.5 mm to 6 mm. And the control group subjects with the single glasses was included. The effectiveness of Orthokeratology was measured by axial length progression. The visual quality of subjects was evaluated by a questionnaire, contrast sensitivity and wavefront aberration.

Official Title
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Effects of Different Designs of Orthokeratology Lens on Myopia Control and Visual Quality

Conditions
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Myopic Progression

Intervention / Treatment
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* Device: Orthokeratology lens


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Myopia: between -1.00D and 4.00D in both eyes Astigmatism: <1.5D for with-the-rule astigmatism, <1.00D for the against-the-rule astigmatism Visual acuity: the best corrected vision acuity(BCVA)≥20/20 in both eyes Subjects that volunteer to participate in the clinical trial and sign informed consent Exclusion Criteria: Contraindications of wearing Ortho-K. Diagnosis of strabismus, amblyopia and other refractive development of the eye or systemic diseases. Any type of strabismus or amblyopia Systemic condition which might affect refractive development (for example, Down syndrome, Marfan's syndrome) Ocular conditions which might affect the refractive error (for example, cataract, ptosis)

Ages Eligible for Study
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Minimum Age: 8 Years
Maximum Age: 13 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: Factorial Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Single-vision glasses<br>Subjects wearing single-vision glasses CR-39 | |
| Experimental: Orthokeratology lenses group 1<br>Subjects wearing orthokeratology lenses of 5mm optical zone. | Device: Orthokeratology lens<br>* The intervention was according to the design of different optical zone and peripheral reverse curve<br>* Other names: Ortho-K;|
| Experimental: Orthokeratology lenses group 2<br>Subjects wearing orthokeratology lenses of 5.5mm optical zone. | Device: Orthokeratology lens<br>* The intervention was according to the design of different optical zone and peripheral reverse curve<br>* Other names: Ortho-K;|
| Experimental: Orthokeratology lenses group 3<br>Subjects wearing orthokeratology lenses of 6mm optical zone. | Device: Orthokeratology lens<br>* The intervention was according to the design of different optical zone and peripheral reverse curve<br>* Other names: Ortho-K;|
| Experimental: Orthokeratology lenses group 4<br>Subjects wearing orthokeratology lenses of 6mm optical zone and the increased height of peripheral reverse curve. | Device: Orthokeratology lens<br>* The intervention was according to the design of different optical zone and peripheral reverse curve<br>* Other names: Ortho-K;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in axial length in 2 years | The axial length was measured by AL-scan | Every 6 months for a period 2 years | 
| Changes in Cycloplegic subjective refraction in 2 years | The cycloplegic subjective refraction was evaluated by optometrist | Every 6 months for a period 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in visual questionnaire as compared to baseline（Postoperative 6 months, 12 months, 18 months and 24 months） | The symptoms score measured by a visual questionnaire, each symptom was evaluated on a scale of 0 to 10. | baseline, postoperative 6 months, 12 months, 18 months and 24 months | 
| Change in High-order aberrations (HOAs) in microns as compared to baseline(Postoperative 6 months, 12 months, 18 months and 24 months) | Ocular aberration measured by Zeiss i. Profiler Plus aberrometer | baseline, postoperative 6 months, 12 months, 18 months and 24 months | 
| Change in contrast sensitivity as compared to baseline(Postoperative 6 months, 12 months, 18 months and 24 months） | Contrast sensitivity measured by Stereo optical 6500 | baseline, postoperative 6 months, 12 months, 18 months and 24 months | 
| Change in choroidal thickness captured by Optical Coherent Tomographer (OCT) as compared to baseline(Postoperative 6 months, 12 months, 18 months and 24 months） | choroidal thickness captured by Optical Coherent Tomographer (OCT) and measured using a customized software | baseline, postoperative 6 months, 12 months, 18 months and 24 months | 
| Change in Corneal epithelial thickness captured by Optical Coherent Tomographer (OCT) as compared to baseline(Postoperative 6 months, 12 months, 18 months and 24 months） | Corneal epithelial thickness captured by Optical Coherent Tomographer (OCT) customized software | baseline, postoperative 6 months, 12 months, 18 months and 24 months | 
| Change in corneal biomechanics parameters (SSI) as compared to baseline (Postoperative 6 months, 12 months, 18 months and 24 months） | Corneal response parameters(SSI) was evaluated by Corvis ST. | baseline, postoperative 6 months, 12 months, 18 months and 24 months | 
| Change in peripheral refraction as compared to baseline (Postoperative 6 months, 12 months, 18 months and 24 months） | Peripheral refraction measured by multispectral refraction topography | baseline, postoperative 6 months, 12 months, 18 months and 24 months | 
| Change in corneal surface regularity index (SRI) as compared to baseline (Postoperative 6 months, 12 months, 18 months and 24 months） | The corneal surface regularity index (SRI) was measured by Corneal Topography. | baseline, postoperative 6 months, 12 months, 18 months and 24 months | 
| Change in corneal surface asymmetry index (SAI) as compared to baseline (Postoperative 6 months, 12 months, 18 months and 24 months） | The corneal surface asymmetry index (SAI) was measured by Corneal Topography. | baseline, postoperative 6 months, 12 months, 18 months and 24 months |