Department of Ophthalmology, Mayo Clinic, Rochester, MN 55905, USA.
Cornea. 2010 Sep;29(9):1042-7. doi: 10.1097/ICO.0b013e3181cc7a60.
The center method of corneal endothelial cell analysis is rapid but excludes the outermost digitized cells of a contiguous group from analysis; the flex-center method (Konan, Inc) is a modification that includes analysis of the outermost cells, which is advantageous in images with few cells. In this study, we examined agreement among the flex-center, center, and corner (standard) methods of endothelial analysis.
Identical cells in endothelial images of 10 normal corneas and 10 corneas after penetrating keratoplasty (PK) were analyzed by each method. Agreement among methods for endothelial cell density (ECD), coefficient of variation of cell area (CV), and the percentage of hexagonal cells (HEX) was assessed by using a Student-Newman-Keuls procedure.
In normal corneas, there were small (clinically insignificant) differences among methods for ECD (P < 0.001) (mean +/- SD: flex center, 2846 +/- 248 cells/mm; center, 2870 +/- 253 cells/mm; and corner, 2892 +/- 254 cells/mm), CV (P < 0.001) (flex center, 33% +/- 3%; center, 30% +/- 3%; and corner, 30% +/- 3%), and HEX (P = 0.004) (flex center, 60% +/- 6%; center, 60% +/- 8%; and corner, 58% +/- 7%). In PK corneas, the methods agreed for ECD (P = 0.06) (flex center, 908 +/- 319 cells/mm; center, 912 +/- 307 cells/mm; and corner, 929 +/- 333 cells/mm) but disagreed for CV (P = 0.02) (flex center, 35% +/- 13%; center, 30% +/- 10%; and corner, 35% +/- 15%) and HEX (P = 0.02) (flex center, 56% +/- 19%; center, 54% +/- 17%; and corner, 43% +/- 23%).
ECD agreed among methods in normal and PK corneas, whereas morphometric data agreed poorly in PK corneas.
角膜内皮细胞分析的中心法快速，但会排除连续组最外数字化细胞的分析；Konan 公司的 Flex-Center 方法是一种修改方法，可纳入对外围细胞的分析，这在细胞数量较少的图像中是有利的。本研究旨在探讨 Flex-Center、Center 和 Corner（标准）三种内皮分析方法之间的一致性。
对 10 例正常角膜和 10 例穿透性角膜移植术后角膜的内皮图像进行相同细胞分析，采用上述三种方法进行分析。采用学生-纽曼-凯斯法评估三种方法的内皮细胞密度（ECD）、细胞面积变异系数（CV）和六边形细胞百分比（HEX）的一致性。
在正常角膜中，三种方法的 ECD（P < 0.001）（均值 ± SD：Flex-Center 为 2846 ± 248 个/平方毫米；Center 为 2870 ± 253 个/平方毫米；Corner 为 2892 ± 254 个/平方毫米）、CV（P < 0.001）（Flex-Center 为 33% ± 3%；Center 为 30% ± 3%；Corner 为 30% ± 3%）和 HEX（P = 0.004）（Flex-Center 为 60% ± 6%；Center 为 60% ± 8%；Corner 为 58% ± 7%）之间存在较小差异（临床意义不大）。在 PK 角膜中，三种方法在 ECD 方面具有一致性（P = 0.06）（Flex-Center 为 908 ± 319 个/平方毫米；Center 为 912 ± 307 个/平方毫米；Corner 为 929 ± 333 个/平方毫米），但在 CV（P = 0.02）（Flex-Center 为 35% ± 13%；Center 为 30% ± 10%；Corner 为 35% ± 15%）和 HEX（P = 0.02）（Flex-Center 为 56% ± 19%；Center 为 54% ± 17%；Corner 为 43% ± 23%）方面存在差异。
在正常和 PK 角膜中，ECD 在方法之间具有一致性，而 PK 角膜的形态计量数据一致性较差。
