Tissue utilization at the Minnesota Lions' Eye Bank.
The purpose of this study was to examine the utilization of corneas procured by the Minnesota Lions' Eye Bank to determine why corneas were excluded from transplantation and to identify methods to safely increase the number of tissues made available for transplantation. We performed a retrospective review of the eye bank charts of 2,382 corneas evaluated by the Minnesota Lions' Eye Bank between December 1, 1992 and November 30, 1993. During that time 748 corneas (31%) were made available for transplantation; 1,597 (67%) were directed toward research or training. Thirty-seven corneas (1.5%) were disposed of for safety reasons. Six hundred and sixty of the corneas which were excluded from transplantation (40%) were excluded for a donor aged over 75 years. Three hundred and ninety-one corneas (24%) were rejected because of a contraindication in the donor's past ocular or medical history. Another 395 corneas (24%) were excluded for poor tissue quality. The most common reason for exclusion of tissue based on tissue quality was abnormalities seen on specular microscopic examination (200 corneas). Of interest, only 14 corneas were rejected for low endothelial cell counts. This review of our tissue evaluation process has led us to reevaluate and change our policy regarding exclusion of corneas for epithelial defects and arcus senilis. These data suggest that further evaluation of the abnormalities seen on specular microscopic examination and their validity as exclusion criteria should be undertaken. Other areas for further evaluation are how to improve the timeliness of tissue procurement and whether excluding all tissues over age 75 years and all postsurgical eyes is valid.