Biomechanical properties of different corneal cross-linking (CXL) irradiances
Session Details
Session Title: Presented Poster Session: Cornea IV
Venue: Poster Village: Pod 3
First Author: : S.Chen CHINA
Co Author(s): : Y. Zheng
Abstract Details
Purpose:
To evaluate whether different Corneal Cross-Linking (CXL) Irradiances with a constant delivered total energy could achieve the same increase in corneal material stiffness based on corneal inflation test.
Setting:
The Affiliated Eye Hospital, Wenzhou Medical University.
Methods:
126 healthy white Japanese rabbits were randomly divided into 7 groups. All the left eys served as treat group,and all right eyes as normal group.6 groups were exposed to riboflavin 0.22% and UV-A(370nm) irradiationiation of equal total energy (3mW/cm 2 for 30 minutes, 9mw/cm2 for 3 minutes, 45 mW/cm 2 for 2 minutes,90 mW/cm 2 for 1 minute). The control eyes were exposed to riboflavin without irradiation. 12 corneas of each group were prepared for inflation test, while other 6 specimens were processed for electron microscopy to measure the fibril diameter and interfibril spacing.
Results:
The stiffening effect of CXL decreased when using high irradiation/short irradiation time settings. At 0.010 MPa stress stage, it showed significant differences between 3 mW group and the NUVA group (p <0.05）, 9 mW group and the NUVA group (p <0.05). Compared with the NUVA group, the tangent modulus in 3 mW group was significantly increased by 212.5 %, the 9 mW group increased by 196.8 %.The interfibril spacing were significant lower in 3 mW group and 9mW group (p <0.05），However, fibril diameter kept the similar (p >0.05).
Conclusions:
The effect of biomechanical properties stiffening and interfibril space narrowing of rabbit cornea underwent corneal collagen cross-linking decreased with increasing irradiance using inflation after a week. Therefore the Bunsen-Roscoe law might not be readily used in corneal collagen cross-linking. Increased oxygen consumption associated with higher irradiances may be a limiting factor leading to reduced treatment efficiency.
Financial Disclosure:
NONE
