Characteristics of Semiautomated Endothelial Cell–Density Measurements Among Corneal Donor Eyes

Abstract

ImportanceEndothelial cell density in corneal donor eyes remains a critical component in selecting tissue suitable for corneal transplant.ObjectiveTo describe an anomaly in endothelial cell density discovered in a large cohort of corneal donor eyes.Design, Setting, and ParticipantsDonor information for this cross-sectional study was obtained from the CorneaGen eye bank for donors from June 1, 2012, to June 30, 2016. Endothelial cell density was reported by eye bank technicians for each eye. The retrospective donor data set included donor demographics, endothelial cell count, time of death, medical and surgical history, and suitability for transplant. The donor data set contained information on donated eyes over the 4-year period.Main Outcomes and MeasuresEndothelial cell–density heat map, 2-dimensional binned plots, and bayesian change point analysis.ResultsA total of 48 207 donated eyes were evaluated. Mean (SD) cell count was 2717 (448) cells/mm2, and mean (SD) donor age was 58 (13) years. Heat maps using 2-dimensional binned plots demonstrated accentuated endothelial cell density results particularly at and immediately above 2500 cells/mm2 with a small gap right under this figure. A bayesian change point analysis revealed a change point at exactly this location as well.Conclusions and RelevanceData from this cross-sectional study suggest a discontinuity in endothelial cell–density measurements just below 2500 cells/mm2. This anomaly suggests that the semiautomated counting technique used in this cohort preferentially skipped over measurements just below this cutoff. Whether this represents an automation error, or more likely, a subjective human bias, requires further study.