Evaluation of corneal elastic modulus based on Corneal Visualization Scheimpflug Technology

Area of Science:

• Ophthalmology
• Biomechanical Engineering
• Medical Devices

Background:

• Corneal biomechanical properties are crucial for diagnosing eye diseases and planning corneal surgery.
• Current devices like Corvis ST offer biomechanical data but cannot directly measure corneal elastic modulus.
• A new method is needed to extract this vital parameter.

Purpose of the Study:

• To develop and validate a method for determining corneal elastic modulus using Corvis ST results.
• To establish normal ranges for corneal elastic modulus in rabbits and humans.
• To investigate the correlation between corneal elastic modulus and intraocular pressure.

Main Methods:

• Applied Reissner's theory for shallow spherical shells to Corvis ST data.
• Measured corneal elastic modulus in rabbit and human eyes using Corvis ST.
• Simulated Corvis measurements using finite element analysis with calculated elastic modulus.

Main Results:

• Established normal corneal elastic modulus ranges: 0.16–0.35 MPa for rabbits and 0.16–0.30 MPa for humans.
• Found positive correlations between corneal elastic modulus, intraocular pressure (IOP), and stiffness parameters.
• Demonstrated agreement between simulated and experimental corneal displacements.

Conclusions:

• The proposed method for determining corneal elastic modulus from Corvis ST data is convenient and effective.
• This technique enhances the utility of Corvis ST for detailed corneal biomechanical analysis.
• Accurate corneal elastic modulus measurement aids in better diagnosis and surgical outcomes.