Rong Bei, Yan Xiao-ming
Department of Ophthalmology, Peking University First Hospital, Beijing 100034, China.
Zhonghua Yan Ke Za Zhi. 2006 Jan;42(1):17-21.
To observe the microstructure and cellular populations of normal human limbal and central corneas using laser confocal microscope.
The study was consisted of 28 eyes of 15 examiners (age distribution, 16-61 years). After examinations with slit lamp biomicroscopy and ophthalmoscope, the images of superior, inferior limbus and central cornea were acquired by laser confocal microscope. Corneal microstructure and cell morphology were analyzed, and cell densities were measured.
Lateral (x, y axis) and axial (z axis) images of limbal and central cornea were clear and vivid. Limbal palisades of Vogt were visible at the superior and inferior limbus. The red blood cells in the vessel of limbus were visible. The arrangement of surface epitheliums was rather loose, with bright borders and dark cell bodies. The surface epithelial cell density was (812 +/- 297) cells/mm(2) at the superior limbus and (785 +/- 263) cells/mm(2) at the inferior limbus. There was no statistical difference between the two group (P > 0.05). The bright and dendriform Langerhans cells were readily visible just under the epithelial cells. The Langerhans cell density was (288 +/- 102) cells/mm(2) at the superior limbus and (254 +/- 127) cells/mm(2) at the inferior limbus. There was no statistical difference between the two group (P > 0.05). At central cornea, the surface epithelial cells were loose, the borders of the cell were clear and bright, and the cell bodies were dark. The cell density was (1098 +/- 315) cells/mm(2), there were more cells in central cornea than other area of superior and inferior limbus (P < 0.05). The arrangement of basal epithelial cells was tight. Nerve plexus at subepithelium and anterior stroma were prominent with strong brightness. Langerhans cells were occasionally visible, and cell density cannot be measured. Subepithelial nerve fibers were thin with high tortuosity and a lot of branches, and deeper ones were thick with low tortuosity and few branch. In the stroma, separated keratocytes were visible under dark background, the boundaries were vague, the nucleis were bright and spindly. Hexagonal endothelial cells were arranged in order with light cell bodies and dark borders. The thickness of whole cornea, stroma or epithelium was (543.0 +/- 62.9), (462.0 +/- 69.5), (59.9 +/- 11.2) microm respectively.
Laser confocal microscopy provides non-invasive, real-time, in vivo images of limbal and central corneas characterized with refined image definition, exact depth localization. It is valuable for basic research and clinical diagnosis of corneal disease.
使用激光共聚焦显微镜观察正常人角膜缘和中央角膜的微观结构及细胞群体。
本研究纳入15名受试者（年龄16 - 61岁）的28只眼。经裂隙灯生物显微镜和检眼镜检查后，用激光共聚焦显微镜采集上方、下方角膜缘及中央角膜的图像。分析角膜微观结构和细胞形态，并测量细胞密度。
角膜缘和中央角膜的横向（x、y轴）及轴向（z轴）图像清晰、逼真。在上方和下方角膜缘可见Vogt栅栏。角膜缘血管内的红细胞可见。表面上皮排列较为松散，边界明亮，细胞体暗黑。上方角膜缘表面上皮细胞密度为(812±297)个/mm²，下方角膜缘为(785±263)个/mm²。两组间差异无统计学意义（P>0.05）。上皮细胞下可见明亮的树枝状朗格汉斯细胞。上方角膜缘朗格汉斯细胞密度为(288±102)个/mm²，下方角膜缘为(254±127)个/mm²。两组间差异无统计学意义（P>0.05）。在中央角膜，表面上皮细胞松散，细胞边界清晰明亮，细胞体暗黑。细胞密度为(1098±315)个/mm²，中央角膜的细胞比上方和下方角膜缘其他区域更多（P<0.05）。基底上皮细胞排列紧密。上皮下和前基质的神经丛明显，亮度高。偶尔可见朗格汉斯细胞，无法测量细胞密度。上皮下神经纤维细，迂曲度高，分支多，较深的神经纤维粗，迂曲度低，分支少。在基质中，在暗背景下可见散在的角膜细胞，边界模糊，细胞核明亮呈梭形。六边形内皮细胞排列有序，细胞体淡，边界暗。全角膜、基质或上皮的厚度分别为(543.0±62.9)、(462.0±69.5)、(59.9±11.2)μm。
激光共聚焦显微镜可提供角膜缘和中央角膜的无创、实时、体内图像，图像清晰度高、深度定位准确。对角膜疾病的基础研究和临床诊断具有重要价值。
