Corneal Biomechanical Properties Demonstrate Anisotropy and Correlate With Axial Length in Myopic Eyes

This study investigates how corneal biomechanical properties change with increasing axial length in myopic eyes using both ex vivo and in vivo approaches. Human corneal stromal lenticules obtained during SMILE surgery were subjected to planar biaxial tensile testing, revealing significant anisotropy and a reduction in tangent modulus with increasing axial length. The findings demonstrate that corneal stiffness decreases preferentially in the horizontal direction as myopia progresses and highlight limitations of in vivo stiffness indices that assume corneal isotropy, underscoring the importance of anisotropic mechanical assessment in myopic eye biomechanics.