Douthwaite W A, Burek H
Optometry Department, Bradford University, West Yorkshire, UK.
Ophthalmic Physiol Opt. 1995 May;15(3):187-93. doi: 10.1016/0275-5408(95)90570-r.
The purpose of this research was to determine if the conventional keratometer measures tangential or sagittal radius. A Bausch and Lomb keratometer was modified to enable an assessment of vertex radius and p-value to be made on convex conicoidal buttons of known surface form. Calculation of these two parameters was achieved assuming that the keratometer was measuring tangential radius and then repeated assuming a sagittal measurement. The resulting values could then be compared with those obtained by Form Talysurf analysis and by the use of an autokeratometer designed to measure sagittal radius. There was good agreement between the three instruments when the modified Bausch and Lomb keratometer was assumed to measure sagittal radius. We conclude that the Bausch and Lomb keratometer makes a radius measurement closer to the sagittal than the tangential radius of a conicoid of revolution.
本研究的目的是确定传统角膜曲率计测量的是切线半径还是矢状半径。对一台博士伦角膜曲率计进行了改装，以便能够对已知表面形状的凸圆锥按钮进行顶点半径和p值评估。假设角膜曲率计测量的是切线半径，计算这两个参数，然后假设测量矢状半径重复计算。然后可以将得到的值与通过Form Talysurf分析以及使用设计用于测量矢状半径的自动角膜曲率计获得的值进行比较。当假设改装后的博士伦角膜曲率计测量矢状半径时，这三种仪器之间有很好的一致性。我们得出结论，博士伦角膜曲率计测量的半径比旋转圆锥体的切线半径更接近矢状半径。
