ePoster

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Title:

Impact of temperature on the biomechanical effect in epithelium-off corneal cross-linking

Poster Details

First Author: H. Abdshahzadeh SWITZERLAND

Co Author(s):    R. Abrishamchi   E. Torres-Netto   N. Hafezi   J. Randleman   F. Hafezi        

Abstract Details

Purpose:

Oxygen diffusion plays a central role in the efficiency of corneal cross-linking (CXL). Oxygen availability within a tissue increases with reduced temperatures. The purpose of this study was to evaluate whether a reduction of the corneal temperature during CXL might increase oxygen availability and thus enhance the biomechanical effect of CXL in ex vivo porcine corneas.

Setting:

Laboratory for Ocular Cell Biology, Center for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland and ELZA Institute, Dietikon/Zurich, Switzerland

Methods:

One hundred twelve porcine corneas with intact epithelium were divided into 4 groups and analyzed. Prior to corneal soaking with hypo-osmolaric 0.1% riboflavin, the epithelium was removed manually in all groups. Accelerated epithelium-off CXL using 9 mW/cm2 irradiance for 10 minutes was performed either at room temperature (group 1, 24ﾰC) or in a cold room (group3, 4ﾰC). Non-cross-linked corneas (groups 2 and 4) were subjected to the same temperatures and served as controls. The elastic modulus of 5-mm wide corneal strips was analyzed and used to determine corneal biomechanical properties.

Results:

Epithelium-off CXL led to significant increases in the elastic modulus determined between 1% and 5% of strain in stress-strain extensometry when compared to non-cross-linked controls, both at 24ﾰC (p<0.001) and 4ﾰC (p=0.006) . However, no significant difference was found between corneas treated with CXL at 24ﾰC and 4ﾰC (p = 0.384).

Conclusions:

While oxygen plays a central role in corneal cross-linking, the potentially increased diffusion of oxygen in lower tissue temperatures does not appear to play a significant role in the biomechanical efficiency of epithelium-off CXL accelerated protocols in ex vivo porcine corneas.

Financial Disclosure:

None