Abstract
Purpose :
Currently there is no ex vivo model of the equine cornea. We sought to determine if the equine cornea is suitable as an ex vivo model. Specifically, to assess the equine cornea's extracellular matrix and cellularity after 7 days using two different culture techniques (an air/liquid interface and immersion system) to determine the best ex vivo equine corneal model. Our hypothesis is that the air/liquid interface model would be superior to the immersion model system.
Methods :
Equine corneas with 2 mm of perilimbal sclera (n=14) are freshly harvested from horses undergoing humane euthanasia and free of anterior segment disease. One scleral-corneal ring from each horse is randomly placed in the air/liquid interface organ culture system with the contralateral scleral-corneal ring being placed in the immersion condition organ culture system for 7 days. All scleral-corneal rings were evaluated using serial daily gross photography, histology, RT-PCR and TUNEL assay. Freshly harvested healthy equine corneas were utilized as controls for all evaluated parameters.
Results :
Scleral-corneal rings placed in immersion condition had complete loss of corneal transparency on gross photography by 7 days, showed a significant level (p<0.05) of stromal disorganization, significantly increased (p<0.05) αSMA levels on RT-PCR, and apoptosis on TUNEL assay when compared to controls. The air-liquid corneas had weak stromal disorganization on histopathologic examination and were not significantly different from normal equine corneal controls on any other evaluated parameter therefore proving our hypothesis.
Conclusions :
The air-liquid culture condition maintained equine cornea's cellular extra cellular matrix and preserved corneal transparency. Conversely, the immersion system resulted in near complete degradation of the normal equine corneal architecture after 7 days in culture. The air-liquid interface system is a viable option to maintain a normal equine cornea in an ex-vivo setting for translational studies.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.