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人正常晶状体前表面的非球面地形特征

Aspheric topographical features of the anterior surface of the human crystalline lens
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摘要 目的探讨人正常晶状体前表面的地形特征。方法使用三坐标测量仪对人的8只离体眼球晶状体前表面进行扫描,扫描获得的数据通过图形软件surfacerv10.0重建晶状体前表面,计算获取晶状体前表面地形图。对测量的晶状体前表面各处的曲率半径行两因素方差分析。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做曲线回归,计算晶状体表面非对称性指数(LSAI)。转换坐标系后,将晶状体前表面水平径线和垂直径线各点做圆、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,向周边区逐渐平坦。每个晶状体前表面各处的曲率半径均有统计学差异(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与距离的曲线回归显示两者间为3次幂函数关系。从晶状体前表面中央至周边的LSAI逐渐增大。晶状体前表面水平径线和垂直径线做曲线拟合的决定系数为双曲线最大。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,且越靠近中心对称性越好。晶状体前表面由中央区至周边区渐平坦,曲率半径加速变大。人晶状体前表面曲线最接近于双曲线。 Objective To investigate the topography of the anterior surface of the normal human crystalline lens. Methods A non-contact three-coordinate measuring system was utilized to scan the anterior surfaces of 8 human cadaver eye lenses. Acquired data were processed and computer models of the anterior lens surfaces (ALS) were made using the program (Surfacer v10.0). The topography of the ALS were established. Radii of curvature were measured at preset spots over the lens surfaces and two-way ANOVA analysis of variance were performed. Curve regressions were done to determine the correlations of the distances with the lens surface center and the average radii of curvature at the same distances. Lens surface asymmetric indexes (LSAI) were calculated as well. After coordinate system were reconstructed, the horizontal and vertical axes of the modeled lens surface were calculated,and the best curve fitting to any conic section was determined. Results The topography of the ALS indicated that the central zone (the central radius of curvature: 9.18±0.75 mm) was steeper than that of the peripheral zone (16.75±2.28 mm) with a statistically significant difference (P 〈 0.05). The correlation of curve regression of the distances to the surface center with the radii of curvature revealed the third power function. LSAI was increased from the lens surface center (0.68±0.24) to the periphery (13.36±6.02). The dots on the horizontal and vertical longitudes were fitted to four kinds of curves, and the determinating coefficients of hyperbola were the largest ones (0.998 9-0.999 9) among them. Conclusion The ALS exhibits imperfectly rotational symmetry. But according to its approximate circle topographical feature, its rotational symmetry is much better than that of the corneal surface. Also it is more symmetric near to the center. Radii of curvature is increased from the surface center to the periphery nonlinearly but acceleratively. ALS is typically hyperbolic.
出处 《眼科研究》 CSCD 北大核心 2006年第2期172-176,共5页 Chinese Ophthalmic Research
关键词 晶状体 表面地形 三坐标测量仪 human crystalline lens surface topograhy three-coordinate measuring system
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参考文献8

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