Abstract
Purpose :
To compare corneal stiffening in porcine eyes induced by UV-crosslinking using riboflavin solved in 20% dextran solution and hydroxy propyl methyl cellulose (HPMC).
Methods :
Three groups of seven corneas of freshly enucleated porcine eyes were compared regarding their biomechanical properties. Crosslinking with an UVA-irradiance of 9mW/cm2 for 10 minutes was performed on corneas of group one and two using the UVX 2000 lamp (IROC Innocross, Zürich, Switzerland). Group one was treated with 0.1% riboflavin in 20% dextran solution, group two with isotonic solution containing 0.1% riboflavin and 1.0% HPMC and group three served as control group. Stress-strain measurements were performed on 5mm wide corneal strips at strains up to 12% using a material tester (UStrech, Cellscale, Ontario).
Results :
The stress needed for a strain of 12% was increased significantly in corneas of group one (by 56%) and group two (by 123%) compared to the control group three (p≤0.01 for both groups). Between group one and two there was no significant difference regarding the stress-strain measurements (p=0.064), though there was a clear tendency showing more stiffening in group one using the dextran solutions.
Conclusions :
These experiments indicate that the biomechanical stiffening of crosslinking using dextran and HPMC is comparable, however there seems to be a slightly stronger stiffening effect using dextran as a riboflavin carrier which was not statistical significant in this small cohort.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.