Measurements of Corneal Biomechanical Properties Using a Dynamic Scheimpflug Analyzer for Young Healthy Adults in South Korea

Study Overview
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Brief Summary
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The human cornea is affected by the magnitude and velocity of both internal and external forces because the cornea has both static and dynamic resistance components. Considering these natures of the human cornea, many investigators have tried to demonstrate corneal biomechanical properties to understand these characteristics of the cornea. Corneal biomechanical properties are known to influence the accuracy of measurements in intraocular pressure (IOP) and are recognized as important factor to explain the susceptibility of development of glaucomatous damage. Until recently, the only instrument which enabled the in vivo measurements of the ocular biomechanical properties was ocular response analyzer (ORA, Reichert Ophthalmic Instruments, Depew, NY, USA).8 The ORA has been used to assess the biomechanical properties of the cornea according to the dynamic bidirectional applanation process. A dynamic Scheimpflug analyzer (corneal visualization Scheimpflug technology [Corvis ST], OCULUS, Wetzlar, Germany) has been introduced recently and has become a useful instrument for evaluating corneal biomechanical properties. The dynamic Scheimpflug analyzer captures the dynamic process of corneal deformation caused by an air puff using an ultra-high-speed Scheimpflug camera at a rate of up to 4,330 images per second. Until now, well-organized analysis on the normative data of the corneal biomechanical profiles measured with the dynamic Scheimpflug analyzer for young healthy adults has not been reported yet. Hence, in the present study, we aim to conduct normative data analysis for the corneal biomechanical properties with the dynamic Scheimpflug analyzer in a cohort of young healthy adults in South Korea.

Conditions
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Myopia

Intervention / Treatment
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* Device: Dynamic Scheimpflug Analyzer


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participants will be included in analyses if they are 20 to 40 years of age Participants who have myopia with a spherical equivalent (SE) between 0.00 and -11.00 diopters (D) Exclusion Criteria: Participants will be excluded from analyses if they had previous ocular or intraocular surgery, a visual field defect, suspicious optic disc appearance, IOP ≥ 30 mmHg, or presence of corneal abnormalities such as keratoconus and forme fruste keratoconus, corneal scarring that would preclude accurate measurements.

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| myopia patients<br>20 to 40 years of age and have myopia with a spherical equivalent (SE) between 0.00 and -11.00 diopters (D) | Device: Dynamic Scheimpflug Analyzer<br>* Measurements of Corneal Biomechanical Properties Using a Dynamic Scheimpflug Analyzer<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| applanation time (AT) |  | 1 hour | 
| applanation length (AL) |  | 1 hour | 
| corneal velocity (CV) |  | 1 hour | 
| deformation amplitude |  | 1 hour | 
| peak distance |  | 1 hour | 
| radius |  | 1 hour | 
| maximal concave power |  | 1 hour | 
| central corneal thickness (CCT) |  | 1 hour | 
| intraocular pressure (IOP) |  | 1 hour |