Doughty M J, Müller A, Zaman M L
Department of Vision Sciences, Glasgow-Caledonian University, Scotland.
Cornea. 2000 Mar;19(2):148-58. doi: 10.1097/00003226-200003000-00006.
We sought to determine the variance in endothelial cell density (ECD) estimates for human corneal endothelia.
Noncontact specular micrographs were obtained from white subjects without any history of contact lens wear, or major eye disease or surgery; subjects were within four age groups (children, young adults, older adults, senior citizens). The endothelial image was scanned, and the areas from > or =75 cells measured from an overlay by planimetry. The cell-area values were used to calculate the ECD repeatedly so that the intra- and intersubject variation in an average ECD estimate could be made by using different numbers of cells (5, 10, 15, etc.).
An average ECD of 3,519 cells/mm2 (range, 2,598-5,312 cells/mm2) was obtained of counts of 75 cells/ endothelium from individuals aged 6-83 years. Average ECD estimates in each age group were 4,124, 3,457, 3,360, and 3,113 cells/mm2, respectively. Analysis of intersubject variance revealed that ECD estimates would be expected to be no better than +/-10% if only 25 cells were measured per endothelium, but approach +/-2% if 75 cells are measured.
In assessing the corneal endothelium by noncontact specular microscopy, cell count should be given, and this should be > or =75/ endothelium for an expected variance to be at a level close to that recommended for monitoring age-, stress-, or surgery-related changes.
我们试图确定人角膜内皮细胞密度（ECD）估计值的差异。
从无隐形眼镜佩戴史、无重大眼部疾病或手术史的白人受试者获取非接触式镜面显微镜图像；受试者分为四个年龄组（儿童、青年、老年、高龄老人）。扫描内皮细胞图像，通过平面测量法从叠加图中测量≥75个细胞的区域。使用细胞面积值反复计算ECD，以便通过使用不同数量的细胞（5、10、15等）来确定平均ECD估计值的受试者内和受试者间变异。
对年龄在6 - 83岁的个体，每个内皮细胞计数75个细胞时，平均ECD为3519个细胞/mm²（范围为2598 - 5312个细胞/mm²）。各年龄组的平均ECD估计值分别为4124、3457、3360和3113个细胞/mm²。受试者间变异分析显示，如果每个内皮细胞仅测量25个细胞，ECD估计值的预期偏差不超过±10%，但如果测量75个细胞，偏差接近±2%。
在通过非接触式镜面显微镜评估角膜内皮时，应给出细胞计数，并且每个内皮细胞的计数应≥75个，以使预期变异处于接近推荐用于监测年龄、应激或手术相关变化的水平。
