Formula prediction error PE (difference of the SEQ measured after cataract surgery minus the formula predicted SEQ) for the Hoffer Q (pACD), the Holladay 1 (SF), Haigis (a0/a1/a2), and Castrop formula (C / H / R).

SD refers to the standard deviation, 2.5% quantile and 97.5% quantile to the lower and upper boundary of the 95% confidence interval, and IQR to the interquartile range as the difference between the 75% and the 25% quantile. Formula constant optimisation was performed to minimise the sum of squared prediction errors PE. Situation A) refers to the ‘classical’ formulae with standard nK/nC values, with situation B) the formula constants and nK/nC in the main part of the formula were varied for optimisation, with situation C) the formula constants and nK/nC in the main part of the formula were varied to minimise for PE and the PE trend error over corneal radius, and with situation D) a standard optimisation was performed using the nK/nC value from situation B) derived from the other dataset in terms of a cross-validation.

本文中，SD（standard deviation，标准差）、2.5%分位数与97.5%分位数分别指代95%置信区间的上下限，而IQR（interquartile range，四分位距）指75%分位数与25%分位数的差值。本研究通过公式常数优化以最小化预测误差平方和（PE）。其中场景A指代采用标准nK/nC取值的「经典」公式；场景B为对公式常数及公式主体部分的nK/nC进行调整以完成优化；场景C为调整公式常数及公式主体部分的nK/nC，以最小化PE以及随角膜曲率半径变化的PE趋势误差；场景D则采用基于另一数据集通过交叉验证得到的场景B的nK/nC取值，执行标准优化流程。