A comprehensive analysis of eye bank-prepared posterior lamellar corneal tissue for use in endothelial keratoplasty

PURPOSE: The purpose of this study was to assess eye bank-prepared corneal tissue with regards to the accuracy of postcut tissue thickness, endothelial cell loss, and rate of successful processing. METHODS: Details of all 913 corneal tissues processed with an automated microkeratome for use in posterior lamellar transplantation, over a 1-year period, were obtained from a large eye bank. The number and success rate of all attempted cutting procedures were analyzed. The thickness of the corneal button obtained after cutting was compared with the graft thickness requested by the operating surgeon. Changes in endothelial cell density (ECD) during tissue processing were evaluated. RESULTS: The rate of successful tissue preparation increased over the time period examined, from 95% in the first quarter to 99.5% in the fourth quarter. Graft material was frequently slightly thicker than requested by the operating surgeon with 28.3% of tissues cut thicker than requested. Postcut ECD over the entire period increased by an average of 4.7% and was closely related to the starting ECD. CONCLUSIONS: There was a very high rate of successful tissue preparation (98.5%), and early failed attempts at tissue cutting were likely the result of the initial learning curve of the involved technicians. Practical considerations resulted in tissue being cut marginally thicker than requested; this is an issue about which the operating surgeon should be aware, because it may possibly influence tissue handling. The quality of the obtained material, as measured by ECD, was excellent, although the calculated ECD may be prone to measurement artifact.