The study on improved cryopreservation technique of the ultrastructure of corneal endothelial cells.

The traditional corneal cryopreservation technique was improved. We carried out an experimental study that rabbit corneas were cryopreserved by using polyvinylpyrolidone (PVP) as cryoprotective agent and dimethylsulfoxide (DMSO) as the control. The endothelia of cryopreserved corneas were evaluated by scanning and transmission electron microscopy and vital staining. The study shows that PVP is an excellent extracellular cryoprotective agent and has the characteristic of low toxicity or not toxicity to corneal endothelia. PVP is able to enhance the cryoprotective action of DMSO when combined with DMSO. The changes of the ultrastructure of endothelial cells are able to reflect the endothelial viability.