Table 4.
Endothelial cell density (ECD) of homogeneous corneas (group 1, n=30) by automated analysis method: mono-image (each of the three images is analysed in isolation) or tri-image (the three images are analysed simultaneously) for 50 and 300 cells, and comparisons with manual count
| Analysis method | No | Mean ECD (cells/mm2(SD, range) | Mean ECD (cells/mm2) discrepancy with manual count (p) | Pearson's r* |
| Mono 50 (image 1) | 30 | 2473 (389, 1773–3816) | 139 (p=0.003) | 0.81 |
| Mono 50 (image 2) | 30 | 2400 (357, 1805–3460) | 66 (p=0.123) | 0.78 |
| Mono 50 (image 3) | 30 | 2381 (329, 1912–3344) | 47 (p=0.172) | 0.83 |
| Mono 300 (image 1) | 28† | 2480 (363, 1782–3533) | 128 (p=0.001) | 0.88 |
| Mono 300 (image 2) | 28† | 2390 (324, 1814–3367) | 76 (p=0.040) | 0.82 |
| Mono 300 (image 3) | 29† | 2398 (313, 1897–3174) | 63 (p=0.032) | 0.88 |
| Tri image 50 | 30 | 2447 (363, 1865–3636) | 113 (p=0.002) | 0.90 |
| Tri image 300 | 30 | 2422 (312, 1862–3448) | 87 (p=0.001) | 0.93 |
| Manual count | 30 | 2334 (245, 1781–2990) | – | – |
*all p values <0.001.
†Missing data: 300 cells uncountable due to adequate or medium image quality. ‡‡The manual count underestimated ECD by a mean 3.8% (mean: 90 cells/mm2, range 47–139) in comparison with the automated analyses. Correlations between automated-analysis methods and manual count were good (r = 0.78–0.88) in mono-image and excellent (r = 0.90–0.93) in tri-image.
ECD = endothelial cell density, SD = standard deviation, Mono 50 = analysis of one image and 50 cells, Mono 300 = analysis of one image and 300 cells, Tri-image 50 = analysis of three images simultaneously and 50 cells, tri-image 300 = analysis of three images simultaneously and 300 cells.