Pentacam TNP在角膜屈光手术后人工晶状体度数计算中的应用研究

Application of Pentacam TNP in calculating the intraocular lens power after corneal refractive surgery

目的:评估Pentacam系统角膜净屈光力(TNP)模式3 mm环的角膜曲率值联合SRK/T公式[简写为TNP 3 mm(SRK/T)]预测屈光手术后白内障患者人工晶状体(IOL)度数的准确性。方法:回顾性研究。收集2019-07/2021-12 LASIK或PRK术后行白内障手术患者35例50眼。术前使用TNP 3 mm(SRK/T)计算IOL度数50眼,使用Barrett True-K公式计算IOL度数34眼,使用Olsen 2公式计算IOL度数41眼,每例患者术前至少使用2种公式计算IOL度数,记录患者术后3 mo实际屈光度。比较三种测算方法下IOL度数的预测误差(PE),分析PE在±0.5、±1.0 D以内的患眼比例。结果:术后3 mo,TNP 3 mm(SRK/T)、Barrett True-K、Olsen 2 PE分别为-0.02±0.63、-0.54±0.80、0.25±0.80 D(P<0.001),PE在±0.5 D内患眼分别为66%(33/50)、44%(15/34)、37%(15/41)(P<0.05);PE在±1.0 D内患眼分别为88%(44/50)、71%(24/34)、80%(33/41)(P>0.05)。结论:Pentacam TNP 3 mm(SRK/T)法操作简便,预测屈光手术后白内障患者IOL度数具有较好的准确性。

AIM:To assess the accuracy of predicting intraocular lens(IOL)power after myopic refractive surgery using the Pentacam system’s true net power(TNP)in the 3 mm zone combined with the SRK/T formula[i.e.TNP 3 mm(SRK/T)].METHODS:Retrospective study.This study enrolled 35 cases(50 eyes)of patients undergoing cataract surgery after laser assisted in situ keratomileusis(LASIK)or photorefractive keratectomy(PRK)from July 2019 to December 2021.Preoperatively,IOL power of 50 eyes,34 eyes and 41 eyes was calculated by TNP 3 mm(SRK/T),Barrett True-K and Olsen 2 formulas,respectively,with at least 2 formulas used to calculate IOL power for each patient.The actual diopter was recorded 3 mo postoperatively.Prediction errors(PE)of IOL power were compared among the three calculation methods,and the proportion of eyes with PE within±0.5 D and±1.0 D was analyzed.RESULTS:The PE at 3 mo postoperatively for TNP 3 mm(SRK/T),Barrett True-K,and Olsen 2 was-0.02±0.63,-0.54±0.80,and 0.25±0.80 D,respectively(P<0.001).The proportions of PE within±0.5 D were 66%(33/50),44%(15/34)and 37%(15/41),respectively(P<0.05);the proportions of PE within±1.0 D were 88%(44/50),71%(24/34)and 80%(33/41),respectively(P>0.05).CONCLUSION:The Pentacam TNP 3 mm(SRK/T)method is simple to operate and provides accurate calculation of IOL power after corneal refractive surgery.