Comparison Between TICL and ICL+AK for High Myopic Astigmatism

Study Overview
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Brief Summary
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To compare the outcomes of a toric Implantable Collamer Lens (ICL) and a spherical Implantable Collamer Lens combined with astigmatic keratotomy (AK) in the correction of high myopic astigmatism.

Official Title
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Comparison Between Toric and Spherical Implantable Collamer Lens Combined With Astigmatic Keratotomy for High Myopic Astigmatism

Conditions
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Astigmatism, High Myopia

Intervention / Treatment
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* Device: Toric Implantable Collamer Lens
* Device: ICL + Astigmatic keratotomy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age ranged from 18 to 40 years, myopia greater than -8.00 diopters (D), and refractive cylinder in the range of 1.50D to 5.50D, for the patients who were planned to undergo AK+ICL implantation, the axial difference between the corneal astigmatism and the manifest refractive astigmatism was less than 10 degree, a stable refractive error during the previous 2 years, anterior chamber depth more than 2.8 mm, endothelial cell density (ECD) more than 2500 cells/mm2, and scotopic pupillary diameter less than 7 mm. Exclusion Criteria: subjects had significant irregular astigmatism, corneal pathological changes, glaucoma, ocular inflammation, or previous ocular trauma or surgery.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 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: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Prospective comparative case series
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Toric Implantable Collamer Lens<br>Subjects in this group will implant Toric Implantable Collamer Lens for high myopic astigmatism | Device: Toric Implantable Collamer Lens<br>* uses Toric Implantable Collamer Lens implantation to correct the high myopic astigmatism.<br>|
| Experimental: ICL+ Astigmatic keratotomy<br>Subjects in this group will implant Implantable Collamer Lens and combined with astigmatic keratotomy for high myopic astigmatism | Device: ICL + Astigmatic keratotomy<br>* uses Implantable Collamer Lens implantation combined with Astigmatic keratotomy to correct the high myopic astigmatism<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Uncorrected Visual Acuity (UCVA) at distance | measured at 5 meter | 2 years after surgery | 
| astigmatism | astigmatism getting from subjective refraction | 2 years after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Best Corrected Visual Acuity (BCVA) at distance | subjective refraction | 2 years after surgery | 
| Spherical Equivalent (SE) | subjective refraction | 2 years after surgery | 
| mean postoperative BCVA/mean preoperative BCVA | safety index | 2 years after surgery | 
| mean postoperative UCVA/mean preoperative BCVA | efficacy index | 2 years after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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toric, astigmatism, high myopia, phakic intraocular lens, astigmatic keratotomy