Tensile biomechanical properties and constitutive parameters of human corneal stroma extracted by SMILE procedure

The biomechanical behavior of human corneal stroma under uniaxial tension was investigated by the experimental analysis of cornea stromal lenticules taken out by corneal refractive surgery. Uniaxial tests were conducted to determine their stress-strain relationship and tensile strength. The Gasser-Ogden-Holzapfel (GOH) model was used to describe biomechanical behavior of the corneal stroma. The theoretical stress-strain relationship of the GOH model in the uniaxial tensile test was deduced. The corneal specimens were collected from ten patients (4 male and 6 female), aged from 17 to 36. The differences between corneal stress-strain relationship in the horizontal and vertical direction were compared. The constitutive parameters C10, k1 and k2 were evaluated through least squares curve-fitting of experimental data.