三种无病史资料人工晶状体度数计算公式在角膜屈光术后白内障手术中的应用比较

目的：评价3种无病史资料人工晶状体（IOL）度数计算公式在角膜屈光手术后行白内障手术时IOL度 数计算中的准确性。方法：前瞻性系列病例研究。收集2016年10月至2019年10月就诊于汉口爱尔眼科医院白内障科既往有角膜屈光手术病史的白内障手术患者23例（31眼）。登录美国屈光与白内障 手术协会网站（ASCRS）,通过其提供的无病史资料法的角膜屈光术后IOL度数计算公式（Shammas公 式、Haigis-L公式、Barrett True-K公式）进行IOL度数计算,得出3种计算公式的预测IOL度数,综合选择合适的IOL度数。术后1个月行客观验光后进行主觉验光获得术后实际屈光状态,根据术后验光 结果计算3种公式的屈光预测误差（RPE）,其绝对值为屈光绝对误差（RAE）。采用单样本t经验比较 RPE与0的差异,单因素方差分析比较不同方法间RPE、RAE的差异,使用卡方检验比较3种方法中 RPE<±0.25 D、<±0.5 D、<±0.75 D、<±1.00 D内的眼所占百分比的差异。结果：3种计算公式的 RPE与0比较,差异均有统计学意义（t=-3.305,P=0.002;t=-2.788,P=0.009;t=-2.528,P=0.017）。 3种计算公式的RPE整体差异有统计学意义（F=2.653,P=0.023）;两两比较发现,Barrett True-K公式 分别与Shammas公式、Haigis-L公式差异均有统计学意义（P=0.017、0.030）。3种计算公式的RAE整 体差异有统计学意义（F=4.554,P=0.013）;两两比较发现,Barrett True-K公式分别与Shammas公式、 Haigis-L公式差异均有统计学意义（P=0.015、0.017）,Shammas公式与Haigis-L公式差异有统计学意义 （P=0.010）。3种计算公式术后RPE<±0.25 D、<±0.50 D、<±1.00 D以内的比例差异均有统计学意义 （χ2 =11.682,P=0.026;χ2 =9.042,P=0.022;χ2 =8.017,P=0.013）,其中,Barrett True-K公式的各RPE级别 比例明显高于Shammas公式和Haigis-L公式,差异均有统计学意义（均P<0.05）。结论：与Shammas公式、 Haigis-L公式相比,Barrett True-K公式在无病史资料角膜屈光术后IOL度数计算中准确性更高。角膜 屈光术后白内障手术IOL度数计算问题仍需进一步研究,临床上建议参考多种公式进行综合选择。

Comparison of Three Formulas for Calculating Intraocular Lens Power after Corneal Refractive Surgery Without Including Medical History Data in Cataract Surgery

Objective: To evaluate the accuracy of three formulas for calculating intraocular lens power after corneal refractive surgery without including medical history data after corneal refractive surgery. Methods: A totalof 31 eyes of 23 patients who had corneal refractive surgery for myopia and subsequent cataract surgery in Hankou Aier Eye Hospital from October 2016 to October 2019 were included in the study. Three IOL powers were calculated by the three prediction formulas (including Shammas formula, Haigis-L formula and Barrett True-K formula) without medical history using the ASCRS online calculator. The suitable IOL power was selected. One month after the operation, subjective perception was measured to obtain the actual postoperative refractive state. Refractive prediction error (RPE) and refractive absolute error (RAE) of the three formulas were calculated according to the optometric testing results. The accuracy of the different IOL calculation formulas was compared. The percentages of eyes within RPE <±0.25 D, <±0.5 D, <±0.75 D and <±1.00 D were calculated. Results: The RPE calculated by the three formulas was significantly different from "0" (t=-3.305, P=0.002; t=-2.788, P=0.009; t=-2.528, P=0.017), and the RPE calculated by the three formulas was significantly different overall (F=2.653, P=0.023). The RPE for the Barrett True-K formula was significantly different from those for the Shammas formula and Haigis-L formula (P=0.017, 0.030). The RAE calculated by the three formulas was significantly different overall from those for the Shammas formula and Haigis-L formula (P=0.015, 0.017). The RAE for the Shammas formula was significantly different from that for Haigis-L formula (P=0.010). The proportions of RPE <±0.25 D, <±0.5 D and <±1.00 D after the operation were significantly different overall for the 3 formulas (χ2 =11.682, P=0.026; χ2 =9.042, P=0.022; χ2 =8.017, P=0.013). The percentages of RPE within ±0.25 D, ±0.5 D and ±1.00 D for the Barrett True-K formula were significantly higher than those for the other formulas (P<0.05). Conclusions: The Barrett True-K formula has a higher accuracy in the calculation of IOL power after refractive surgery when medical history is not included. The calculation of IOL degree in cataract surgery after corneal refractive surgery still needs further study. It is suggested to consult a variety of formulas for comprehensive selection.