CORNEAL PRESERVATION IN ORGAN-CULTURE

The increasing success of corneal grafting is closely linked to the improvements made in corneal preservation. A variety of methods are in use today, aiming at a prolonged storage interval that not only preserves corneal tissue but also improves corneal endothelial cell viability. In most storage techniques, there is an inverse correlation between resulting endothelial cell viability and duration of the storage period. Current efforts are aimed at prolonging the storage interval, while avoiding its negative effects on endothelial cell survival. This may be achieved by protecting cells from postmortem or cold-induced degenerative changes as well as applying growth factors for an induction of endothelial cell regeneration in vitro or after grafting. The corneal organ culture method of corneal preservation supports vital functions of the corneal endothelium. Here the preservation itself serves as a viability test, enabling the observation of the endothelial cell response to the culture conditions. Because corneal organ culture is more complicated to perform than refrigerated storage, this method has only been accepted for routine preservation in a few US and European eye banks. The most critical aspect of corneal organ culture is the reexamination of the corneal endothelium immediately before grafting. Because the tissue undergoes changes during the preservation techniques, knowledge of these changes is mandatory for its application as a routine eye bank procedure.