Biomechanical Characterization of Central Corneal Region Using Inflation Test and its Application to Predicting...

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Materials Science

Background:

• Corneal biomechanical properties are crucial for ocular health and surgical outcomes.
• Accurate characterization of corneal tissue under intraocular pressure (IOP) is essential for understanding its mechanical behavior.
• Existing methods for determining corneal biomechanics have limitations in accuracy and applicability.

Purpose of the Study:

• To determine the biomechanical properties of the central cornea under IOP.
• To develop and validate an accurate method for predicting corneal biomechanical responses.
• To establish a reliable stress-strain relationship in the corneal thickness direction.

Main Methods:

• A rabbit corneal inflation test was employed to derive the stress-strain relationship in the corneal thickness direction.
• Finite Element Analysis (FEA) was used to predict corneal biomechanical responses under IOP.
• FEA predictions were compared with those derived from uniaxial tensile tests and optical coherence elastography (OCE).

Main Results:

• The FEA method based on the inflation test demonstrated significantly improved prediction accuracy for apex displacement and central curvature.
• Maximum deviation in apex displacement prediction decreased by up to 73.2% compared to other methods.
• Maximum deviation in central curvature prediction decreased by up to 89.2% compared to other methods.

Conclusions:

• The stress-strain relationship in the corneal thickness direction provides the most accurate prediction of biomechanical responses under IOP.
• The proposed inflation test-based method is an accurate tool for biomechanical characterization of the central cornea.
• This approach enhances our understanding of corneal mechanics and has implications for ophthalmic diagnostics and treatments.