Abstract
Purpose :
To characterize the role of glycosaminoglycans (GAGs) in defining tensile properties of porcine cornea.
Methods :
Corneal samples were excised from porcine eyes and divided into control, buffer, enzyme, enzyme CXL groups. The keratan sulfate (KS) GAGs were enzymatically removed from the specimens by placing them in 100mM sodium acetate buffer containing 0.1 U/ml keratanase II at pH 6.0 and 37 °C for 20 hours. The buffer treated samples were immersed in the buffer solution without keratanase II enzyme and the control samples were used immediately after dissection. The corneal crosslinking (CXL) treatment was used to crosslink GAG depleted samples. The GAG content of samples was determined using Alcian blue staining and Blyscan assay. Furthermore, their tensile response was determined using an RSA-G2 (TA instruments, DE) machine.
Results :
The GAG quantification studies showed that GAG depleted samples had significantly lower GAG density in comparison with control and buffer treated specimens (P < 0.05). No significant difference was seen between tensile behavior of control and buffer treated strips but the tensile stiffness of enzyme treated samples was significantly lower than that of the control samples (P < 0.05). The CXL treatment significantly increased the tensile stiffness of enzyme treated strips (P < 0.05).
Conclusions :
KS GAGs play a significant role in defining tensile properties of porcine corneal stroma and their removal causes significant corneal tensile property softening. Furthermore, the CXL treatment improves the tensile stiffness of GAG depleted samples suggesting that KS GAGs do not affect strengthening effects of this treatment procedure.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.