AIM: To investigate the topography of the anterior surface of the human crystalline lens. ·METHODS: A Non-contact three-coodinate measuring system was utilized to scan the anterior surfaces of 8 human eye lenses in vitro. Acquired data were processed and computer models of the anterior lens surfaces were made using the program (Surfacer v 10.0). The to-pography of the anterior lens surfaces were established. Radii of curvature were measured at preset spots over the lens surfaces and two way analysis of variance was performed. The data were analysed to determine whether the radius of curvature varied systematically with the position on the lens surface from which the measurement was made. Lens surface asymmetric index (LSAI) was defined and calculated. The vertical and horizontal meridians of the modeled lens were calculated, and the best curve fit to any conic section was determined. ·RESULTS: The topography of the anterior lens surface indicated that the central zone (the central radius of curvature is (9.09±0.80)mm was steeper than that of the peripheral zone(17.05±2.20)mm. Two way analysis of variance of the radii of curvature at preset spots over the lens surfaces showed that the differences were statistically significant (P ＜ 0.05). Curve regression of radii of curvature at preset spots and their distances to the surface center revealed that the correlation of them was the third power function. LSAI increased steadily from the lens surface center(0.013±0.005) to the periphery(0.184± 0.065). The dots on the horizontal and vertical meridians were fit to four kinds of curves, and the determinate coefficient of hyperbola fit were the largest (0.9989-0.9999). ·CONCLUSION: The anterior lens surface is imperfectly rotational symmetric. Moreover, the nearer to the center, the more rotational symmetric it is. Radii of curvature increase nonlinearly from the surface center to the periphery. Anterior lens surface is typically hyperbolic.%目的:探索人正常晶状体前表面的地形特征.方法:使用三坐标测量仪扫描8只人离体眼球晶状体前表面,通过图形软件surflacer v10.0将扫描获得的数据重建晶状体前表面,计算获取晶状体前表面地形图.测量出晶状体前表面各处的曲率半径,并作两因素方差分析.计算离晶状体前表面中心点不同距离处的平均曲率半径,并和离中心点的距离作曲线回归.计算晶状体表面非对称性指数(Lens Surface Asymmetric Index,LSAI).转换坐标系后,将晶状体前表面水平经线和垂直经线各点作圆、椭圆、抛物线、双曲线等的曲线拟合.结果:人晶状体前表面地形图显示中央区较陡峭(中心曲率半径9.09±0.80mm),往周边区逐渐平坦(周边曲率半径17.05±2.20mm).每个晶状体前表面各处的曲率半径作两因素方差分析均有统计学差异(P＜0.05).离晶状体前表面中心点不同距离处的平均曲率半径和距离作曲线回归显示两者间为三次幂函数关系.LSAI从晶状体前表面中央(0.013±0.005)至周边(0.184±0.065)逐渐增大.晶状体前表面水平经线和垂直经线作曲线拟合的决定系数为双曲线最大(0.9989-0.9999).结论:人晶状体前表面地形图近似为圆形,但并非完美的旋转对称,晶状体前表面越靠近中心对称性越好.晶状体前表面由中央区至周边区逐渐变平坦,而且曲率半径呈现加速变大趋势.人晶状体前表面曲线最接近于双曲线.
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