Corneal Biomechanics and Corneal Reshaping Therapy

Study Overview
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Brief Summary
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The aim of the proposed study is to investigate the predictive value of corneal biomechanical properties in corneal reshaping therapy and the role of these parameters in determining the amount of myopia reduction.

Detailed Description
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Experiment 1: To evaluate changes in corneal biomechanics caused by short-term corneal reshaping therapy. Subjects will wear a conventional RGP lens in one eye, randomly selected, and an orthokeratology lens in the fellow eye, for 30 minutes, 60 minutes and one night, respectively. Corneal stiffness and tangent modulus will be measured before and after each wearing period. Experiment 2: To evaluate changes in and the recovery of corneal biomechanics effected by long-term corneal reshaping and to assess whether corneal biomechanics can predict the rate of corneal reshaping. Subjects will wear orthokeratology lenses for 6 months. Regular follow up visits (1 week, 1 month, 3 months and 6 months) will be arranged to monitor the changes in corneal stiffness and tangent modulus.

Official Title
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Corneal Stiffness and Tangent Modulus to Predict the Rate of Corneal Curvature Change in Corneal Reshaping Therapy

Conditions
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Myopia

Intervention / Treatment
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* Other: Corneal reshaping therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Myopia between -4D to -5D, with-the-rule astigmatism not more than 1.5D, spherical equivalent between -4D to -5.75D, difference between two eyes within 1D, best corrected spectacle visual acuity 0.10 logMAR in each eye Exclusion Criteria: previous corneal reshaping therapy, long-term contact lens wear, ocular disease

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
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Corneal reshaping therapy<br>Subjects will be wearing corneal reshaping lenses for the correction of their myopia | Other: Corneal reshaping therapy<br>* Reshaping the corneal curvature from wearing specific designed rigid gas permeable lenses<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of Corneal Stiffness From Baseline at 6 Months | Corneal Stiffness: in N/mm Corneal parameters usually will stabilize in 1 month, this study will monitor it till 6 months. | At baseline, then change from baseline to 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of Tangent Modulus From Baseline at 6 Months | Tangent modulus: in MPa Corneal parameters usually will stabilize in 1 month, this study will monitor it till 6 months. | At baseline, then change from baseline to 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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corneal reshaping therapy, corneal biomechanics