Comparison of semi-automated center-dot and fully automated endothelial cell analyses from specular microscopy images.

Purpose: To evaluate two specular microscopy analysis methods across different endothelial cell densities (ECDs).

Methods: Endothelial images of one eye from each of 45 patients were taken by using three different specular microscopes (three replicates each). To determine the consistency of the center-dot method, we compared SP-6000 and SP-2000P images. CME-530 and SP-6000 images were compared to assess the consistency of the fully automated method. The SP-6000 images from the two methods were compared. Intraclass correlation coefficients (ICCs) for the three measurements were calculated, and parametric multiple comparisons tests and Bland-Altman analysis were performed.

Results: The ECD mean value was 2425 ± 883 (range 516-3707) cells/mm. ICC values were > 0.9 for all three microscopes for ECD, but the coefficients of variation (CVs) were 0.3-0.6. For ECD measurements, Bland-Altman analysis revealed that the mean difference was 42 cells/mm between the SP-2000P and SP-6000 for the center-dot method; 57 cells/mm between the SP-6000 measurements from both methods; and -5 cells/mm between the SP-6000 and CME-530 for the fully automated method (95% limits of agreement: - 201 to 284 cell/mm, - 410 to 522 cells/mm, and - 327 to 318 cells/mm, respectively). For CV measurements, the mean differences were - 3, - 12, and 13% (95% limits of agreement - 18 to 11, - 26 to 2, and - 5 to 32%, respectively).

Conclusions: Despite using three replicate measurements, the precision of the center-dot method with the SP-2000P and SP-6000 software was only ± 10% for ECD data and was even worse for the fully automated method.

Clinical Trial Registration: Japan Clinical Trials Register ( http://www.umin.ac.jp/ctr/index/htm9 ) number UMIN 000015236.