title: Assessment of the ex vivo biomechanical properties of porcine cornea with inflation test for corneal xenotransplantation.
abstract: OBJECTIVE
  This study aims to obtain the biomechanical properties of porcine cornea so as to provide necessary biomechanical experimental basis for pig-to-human corneal xenotransplantation.
  
  
  METHODS
  Seventeen fresh porcine corneal specimens obtained from pigs aged 4-6 months were examined under inflation conditions to determine the constitutive relationships of the material through dynamic loading conditions (pressure range: 1.47-42.66 mmHg). The forward deflection of porcine anterior corneal apex was measured by the laser displacement sensor. The pressure deformation results were analysed on the basis of shell theory to estimate Young's modulus of the cornea and derive its relationship with intraocular pressure (IOP).
  
  
  RESULTS
  The porcine corneas showed a nonlinear corneal forward displacement/IOP and stress/strain relationship with an initial low stiffness stage and a later high stiffness stage. In spite of the nonlinearity between the internal pressure and apex forward deflection, the relationship between the Young's modulus and the IOP was almost linear.
  
  
  CONCLUSIONS
  Compared with human corneas, porcine corneas exhibited a similar nonlinear behaviour but lower stiffness values. The biomechanical parameters of porcine cornea obtained from this test could be applied to numerical simulations of refractive surgery procedures and lay a foundation for pig-to-human corneal xenotransplantation.
authors.affiliation: Affiliated Eye Hospital of Wenzhou Medical College, Wenzhou 325027, PR China.
authors.forename: F
authors.initials: F
authors.lastname: Bao
authors.forename: L
authors.initials: L
authors.lastname: Jiang
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.forename: D
authors.initials: D
authors.lastname: Zhang
authors.forename: Q
authors.initials: Q
authors.lastname: Wang
authors.forename: Y
authors.initials: Y
authors.lastname: Zeng
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D003315:Cornea / Q000502:physiology*; D055119:Elastic Modulus; D007429:Intraocular Pressure; D013314:Stress, Mechanical; D013552:Swine; D014183:Transplantation, Heterologous