Evaluation of the safety of storage medium for corneal transplants

The results of 27 keratoplasties done at the Royal Adelaide Hospital were analysed. The success rate of the graft was similar whether storage was as whole eyes (60%) or corneo-scleral rims (65%). A modified McCarey-Kaufman medium has been used for 2 years to store the corneo-scleral rims. Phenol red has been added as an indicator of pH change and probable bacterial contamination. Laboratory experiments contaminating this medium with potential pathogens have shown that the indicator is valueless for this purpose. Several antibiotics, alone and in combination, and at varying temperatures of storage, were tested in experiments. None could be relied on to sterilise the media of the inoculated bacteria. Whole eyes are stored in moist chambers containing normal saline with penicillin plus streptomycin which is less able to support bacterial growth. Similar challenge experiments showed that normal saline is not sterilised by the penicillin plus streptomycin.