Aim: To study the feasibility of using the discoloration to evaluate the biomechanical properties after treating with genipin.
Methods: Porcine cadaver eyes were treated for 30min with 1.0% (by w/v) genipin. Untreated samples were used as controls. After treatment, scleral strips of 4.0×10.0-mm(2) were cut. The denaturation temperature (Td) measurement and stress-strain test were performed after taking photograph to analyze the color.
Results: Within 24h after treating with genipin, the sclera exhibited a bluish color which became deeper with time. And the denaturation temperature also was increased gradually. Compared with untreated groups, at 1, 6, 12, 24 and 36h after treatment, the ultimate stress were increased by 56%, 153%, 173%, 225% and 211% respectively. The Young's modulus at 10% strain also increased by 170%, 246%, 264%, 389% and 288% respectively. There were strong correlation between the discoloration and the biomechanical properties (ΔE-Ultimate stress: R(2)=0.892, P=0.00; ΔE-Young's modulus: R(2)=0.602, P=0.00).
Conclusion: Genipin could be used to strengthen collagen gradually in a relatively short time span. And the biomechanical properties could be reliably evaluated via simple visible discoloration.
Keywords: biomechanics; crosslinking; discoloration; genipin; sclera.