Purpose: To compare two semiautomated methods of evaluating endothelial cells of eye bank corneas.
Methods: Using a commercially available semiautomatic endothelial analyzer, seven observers determined the endothelial cell density (ECD), coefficient of variation (CV) of cell area, and the percentage of hexagonal cells (hexagonality) of the light microscopic images of the endothelium of 30 organ-cultured corneas. The image quality was graded as good, average, and poor. Border (contour detection and manual retouch) and center (indicating cell centers) methods for identifying endothelial cells were compared. The interobserver variability in ECD determination (indicating reproducibility) and morphometry was statistically analyzed by using the two methods. The importance of accurate pointing of cell centers was assessed by counting on 10 standard photolithographic mosaics and noting the time taken.
Results: There was no significant difference in the interobserver variability or between ECDs obtained by the border and center methods. Decrease in image quality had a similar influence on both methods. Although measurement of hexagonality was acceptable by both methods, the CV was reliable only with the border method, with a significant underestimation by the center
Method: However, an accurate indication of cell center slightly improved the CV estimation.
Conclusions: Although both the border and center methods of semiautomatic evaluation of eye bank corneas measure similar ECD with a similar reproducibility, only the border method gives a reliable morphometry.