Chapter 4. The Quality of Donor Corneas for Penetrating Keratoplasty

Summary

A review of the literature reveals a general recognition that changes occur in donor corneas during certain periods post mortem and that time limits for each period have been suggested. However, most of the suggestions are based upon indirect clinical observations and are unsupported by controlled experiments. This has led to a wide range of opinion about how long a cornea remains suitable for transplantation. The few controlled investigations have given confusing results. Observation of chemical changes in the aqueous humour and the cornea itself indicates a very short survival time for the tissues, whereas other observations show that even the most delicate corneal cells —the endothelial cells—remain viable for long periods. Nevertheless, it is clear that external environmental conditions greatly influence the donor cornea, temperature, humidity and oxygen supply being the more obvious ones.