QUALITY TESTING - AN ESSENTIAL ACTION IN A CORNEA BANK

Background During a period of 3 months 20% of patients who recieved a corneal transplant showed a prolonged postoperative swelling, of the stroma and an increased number of folds in the epithelium was prolonged. These findings were atypical because there were no complications during the operation and the preoperative examination of the donor cornea showed a normal corneal endothelium. All donor corneas were stored in organ culture before transplantation using minimal essential medium supplemented with 2% fetal calf serum (FCS). This method has been used in the university eye clinic of Hamburg since 1981. In order to establish any correlation between the used organ culture conditions and the clinical findings the different components of the culture medium were checked. We noticed that the serum batch used for organ preservation had been changed at the beginning of the above mentioned period. Patients From April 20th to June 23th, 28 penetrating keratoplasties were performed at the department of ophthalmology of the University Clinic of Hamburg. No complications during the surgical procedure or postoperative infection were detectable. Four weeks after transplantation all transplants showed a normal swelling. Methods The quality of media or sera is not guaranteed by the company where the substances were purchased. We performed clonal growth assays using human or porcine corneal endothelial cells to evaluate the quality of different charges of fetal calf serum. Results It could be demonstrated that the acticity of the serum charge used for organ preservation during the described period had a significantly reduced activity in a clonal growth assay compared with various FCS-charges from different companies. Conclusions After changing the serum batch the problems described above disappeared. We conclude that quality testing of all supplements of the organ culture medium is necessary in a cornea bank to guarantee a reliable standard of corneal preservation. A clonal growth assay is a sensitive test which is suggested to be useful for quality testing.