ABSTRACT
PURPOSE: Corneal donor tissue can be used for a number of different reconstructive surgical operations involving the rehabilitation of injured or degraded anterior, posterior and intermediate corneal lamellas.Potential corneal donor tissues undergo a rigorous screening process including medical evaluation of the endothelial and stromal layers. Depending on this assessment, the tissue´s scope of use is often narrowed down to few types of emergency procedures mainly due to an insufficient number of viable endothelial cells or divergent cell morphology.In addition to all these limitations, one must not ignore the sometimes critical post-preparation degeneration caused by the submerged culturing process itself, leading to epithelial debridement and stromal edema. All these factors reduce the already short supply of donor corneas. In this study, we aim to optimize this culturing process to avoid tissue degradation. METHODS: We used an organ culturing system based on our long established Ex Vivo Eye Irritation Test System (EVEIT) (Spöler et al., 2015). This bioreactor has been modified in size and shape to accommodate human-sized corneal explants. The established mechanisms for supplying the cornea with nutrients and physiologically relevant pressure conditions were adapted to support sterility. Human donor corneas that failed the initial quality protocol and which are released for research were obtained from our cornea bank and inserted in the EVEIT culture system. Corneal integrity was observed during the cultivation period of 19 days. RESULTS: The human cornea observed maintained transparency in contrast to what generally can be observed in the established European culturing system with submersion of the cornea. Final endothelial layer examinations confirmed the presence of viable endothelial cells, as documented during initial corneal bank quality control. CONCLUSION: With this proof of principle, we confirmed that we can maintain the integrity of the human donor cornea in our modified EVEIT organ culture system. Further investigation, optimization and confirmation will be pursued to meet medical regulations.
