Cell Density of the Corneal Endothelium in Human Fetus by Flat Preparation

Purpose. To count the number of the corneal endothelial cells per unit of tissue area in 25 human fetal eyes ranging from 12–40 weeks of gestation with the histologic method. Methods. The endothelium including Descemet's membrane was stained with hematoxylin–eosin by the flat preparation method. We photographed the endothelium using light microscopy. The number of nuclei was counted on each photograph. A calibrated micrometer was photographed with the light microscopy, and this was used to measure the number of corneal endothelial cells per square millimeter. Results. The prenatal endothelial cell density of the human cornea decreases rapidly from 14,095 cells/mm2 (12 weeks of gestation) to 6,820 cells/mm2 (40 weeks of gestation). Conclusion. The estimate of the endothelial cell density at 12 weeks of gestation is twofold higher than the estimate at 40 weeks of gestation.