Toulemont P J, Serdarevic O N
Service Ophthalmologie, Rennes.
J Fr Ophtalmol. 1993;16(8-9):464-71.
The probability method of analysis of astigmatism variations respects both astigmatism components, quantity and axis. The two random variable model that we introduce here analyses cylinder variations and axial variations. After describing the contingency table and the probability table. Expectation of each component and its confidence interval are calculated together with the variance and the standard deviation. Covariance and correlation are calculated. If we want to compare different groups we test cylinders with cylinders and axes with axes. This method does not distort reality and is applicable to the semi meridians from 0 degree to 360 degrees. Only large samples of patients can be studied by this method.
散光变化分析的概率方法兼顾了散光的两个组成部分，即散光量和轴位。我们在此引入的双随机变量模型分析了柱镜度数变化和轴位变化。在描述了列联表和概率表之后，计算每个组成部分的期望值及其置信区间，同时计算方差和标准差。还计算了协方差和相关性。如果我们想比较不同组，就用柱镜度数与柱镜度数比较，轴位与轴位比较。这种方法不会歪曲实际情况，适用于0度至360度的半子午线。此方法仅适用于对大量患者样本进行研究。
