Abstract
Purpose :
To investigate biomechanical behavior of human corneal stroma and obtain its biomechanical parameters.
Methods :
Corneal lenticule extracted from small incision lenticule extraction surgery were cut into specimen. The stress-strain test, creep test and stress relaxation test were performed at room temperature in water bath to evaluate the biomechanical properties of human cornea stroma.
Results :
Low strain tangent modulus（LSTM）was 1.32±0.48MPa, high strain tangent modulus(HSTM) was 51.26±8.23 MPa, strain and stress in fracture point(εD, σD) was 0.52±0.06mm/mm, 13.00±2.51 MPa respectively. The elastic modulus of corneal stroma was 1.27±0.65，1.57±0.57，1.84±0.58MPa respectively at the stress of 0.01, 0.02, 0.03 MPa. At 1.0N constant load, the deformation of the specimen enhanced with time, the change in early time was faster and gradually slowed down in the later period. The creep rate was 4.57±1.67% at 600s. Keeping the length of the corneal specimen 1.5 times as long as the initial length, the stress gradually attenuated with the extension of time, the early attenuation rate was relatively fast at the beginning and slowed down with time, the relaxation rate was 28.49±0.04% at 1h.
Conclusions :
The biomechanical characteristics of normal human cornea stroma are revealed in this study，which lay the foundation for the further research on human cornea．
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.