Purpose

To compare methods for evaluating refractive outcomes after cataract surgery to detect outliers.

Design

Case series database study of the evaluation of diagnostic technology.

Participants

Consecutive patients who had uneventful cataract operations over a 5-year period.

Methods

The intended and postoperative refractive outcome and differences between these were analyzed as a spherical equivalent, cylinder, and spherocylinder. The average keratometry and differences between steep and flat keratometric meridians were used to calculate the intended refractive error.

Main Outcome Measures

Outliers were defined as patients for whom the difference between the intended and postoperative refractive errors was more than 3 standard deviations (SDs) away from the mean.

Results

A total of 9000 patients were included. Twelve patients had missing data and were excluded. The mean intended refractive outcome was −0.12+0.12×2 (95% lower confidence limit [LCL], −1.94+1.06×44; 95% upper confidence limit [UCL], +0.77+1.05×140). The actual postoperative refractive error was −0.30+0.47×6 (95% LCL, −2.36+1.31×36; 95% UCL, +1.00+1.18×148) with a difference from the intended of −0.18+0.35×7 (95% LCL, −1.91+1.22×38; 95% UCL, +0.75+1.09×145). Treating the components of the refractive error independently, outliers were observed in 82 eyes (0.91%) based on the sphere, 46 eyes (0.51%) based on the spherical equivalent, 115 eyes (1.28%) based on treating the cylinder as a scalar, and 76 eyes (0.85%) based on treating the cylinder as a vector. When the differences between the intended and postoperative refractive errors were calculated as a compound spherocylinder, outliers were observed for 233 eyes (2.59%).

Conclusions

Treating the intended refractive outcome as a spherocylinder improves the precision for detecting clinically significant refractive outliers.

中文翻译：

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白内障手术后评估屈光结果

目的

为了比较评估白内障手术后屈光结果以检测异常值的方法。

设计

案例系列数据库研究对诊断技术的评价。

参加者

连续5年内白内障手术顺利的患者。

方法

预期的和术后的屈光结果以及它们之间的差异被分析为球面等效值，圆柱度和球镜度。平均角膜曲率以及陡峭和平坦角膜曲率子午线之间的差异用于计算预期的屈光不正。

主要观察指标

离群值定义为预期屈光不正和术后屈光不正之差与均值相差超过3个标准差（SD）的患者。

结果

总共包括9000名患者。12名患者的数据缺失，被排除在外。平均预期屈光结果为-0.12 + 0.12×2（95％置信度下限[LCL]，-1.94 + 1.06×44； 95％置信度上限[UCL]，+ 0.77 + 1.05×140）。实际术后屈光不正为-0.30 + 0.47×6（95％LCL，-2.36 + 1.31×36; 95％UCL，+ 1.00 + 1.18×148），与预期值的差异为-0.18 + 0.35×7（95 ％LCL，-1.91 + 1.22×38； 95％UCL，+ 0.75 + 1.09×145）。独立处理屈光不正的分量，在以球为基准的82眼（0.91％），以球等效量为基准的46眼（0.51％），以圆柱体为标量的115眼（1.28％）的观察到离群值，将圆柱体视为向量有76眼（0.85％）。

结论

将预期的屈光结果视为球囊可提高检测临床上重要的屈光异常值的精度。