目的 了解正常人的角膜前后表面形态及全角膜厚度，为诊断异常角膜提供参考依据。方法 应用Orbscan角膜地形图仪对46例正常人（46只眼）的角膜进行检测，建立其正常参数。结果 正常人角膜最薄处为（0.55±0.33） mm，平均位于距视轴（0.90±0.51） mm处。32例（70%）角膜最薄点位于颞下方，11例（24%）位于颞上方，2例(4%)位于鼻下，1例(2%)位于鼻上方。角膜厚度以角膜中央最薄（0.56±0.03） mm，角膜上方最厚（0.64±0.03） mm。模拟角膜屈率（Sim K）为（44.24±1.61/43.31±1.66）D, 散光度为（0.90±0.41）D。角膜前表面高度地形图的图形中，岛形最多，其次为不完全嵴形。角膜后表面高度地形图的图形中，岛形最多，其次为规则嵴形及不完全嵴形。在前表面角膜屈率地形图的图形中，对称蝴蝶结形最多，其次为椭圆形及不对称蝴蝶结形。在角膜厚度彩色地形图中，椭圆形最多，其次为圆形。结论 了解正常人全角膜厚度、角膜高度形态及角膜前表面角膜屈率地形图将为诊断异常角膜提供依据。Orbscan 角膜地形图仪是一种测量角膜地形及全角膜厚度的有用工具，在角膜屈光手术中将具有重要的应用价值。%Objective To evaluate the corneal topography and pachymetry on normal eyes. Methods The Orbscan corneal topography system was used to investigate corneal topography and pachymetry on 46 normal subjects. Results In normal eyes, island-shape was the most common type in the elevation topography of anterior corneal surface, followed by incomplete ridge, regular ridge, irregular ridge and unclassified type. For the elevation topography of posterior corneal surface, the most common type was also the island-shape, followed by regular ridge, incomplete ridge and irregular ridge. The thinnest point of cornea in normal eyes was located (0.90±0.51) mm away from the visual axis with the thickness of (0.55±0.33) mm, which was commonly seen at the inferotemporal quarter of cornea, followed by superotemporal, inferonasal and superonasal quarter. The mean corneal thickness was the least in corneal center and greatest in superior part of cornea. For the color-coded map of corneal thickness, oval shape was the commonest type, followed by round shape, eccentric oval shape and eccentric round shape. Conclusions The normal parameters on pan-corneal thickness and corneal shape of both anterior and posterior surface will provide much more useful informations in finding abnormal cornea. Orbscan topography system is a useful instrument for the evaluation of corneal shape and thickness, which is helpful in corneal refractive surgeries.
展开▼
