Freezing of preservation media during corneal tissue transport.

It is important to evaluate donor corneas and media carefully prior to surgery. The eye banks that are responsible for preservation and transportation of donor corneal tissue should continue their efforts to prevent tissue damage, which includes careful placement of vials in properly prepared containers. If placed in direct contact with ice, the ice should be relatively warm and glistening. Direct contact with hard, super-cooled ice should be avoided. If living tissue is frozen without special treatment, ice crystals form in the cells and cell membrane rupture, causing death of the cell. Also, when ice crystals are present, tissue damage could take place when physical impact is caused by motion of the container during transportation.