角膜屈光手术后人工晶状体度数的测算

摘要

目的 评价Pentacam等效角膜屈光力(EKR)代入Holladay I公式联合双K法测算角膜屈光手术后人工晶状体(IOL)度数的准确性.方法 回顾性系列病例研究.收集既往有准分子激光角膜屈光术史白内障患者32例(45眼),所有患者在白内障术前接受Pentacam、IOLMaster检查,分别采用Pentacam EKR法、临床病史法、Haigis-L公式法计算IOL度数.白内障术后1个月进行客观验光,采用Kruskal-Wallis秩和检验和单因素方差分析比较术后屈光度的中值绝对偏差(MedAE)、平均绝对偏差(MAE).结果 Pentacam EKR代入Holladay I公式联合双K法得出MedAE为0.32 D,MAE为0.39 D,术后71％眼屈光误差在±0.50 D范围内,93％眼在±1.00 D范围内,而Haigis-L公式法得出MedAE为0.51 D,临床病史法MedAE为1.48 D.结论 Pentacam EKR代人Holladay I公式联合双K法测算角膜届光手术后IOL屈光度数比较准确.%Objective To investigate the refractive outcomes of intraocular lens (IOL) power calculations after refractive surgery with equivalent keratometry readings (EKR) and the double-K adjustment of the Holladay I formula.Methods In this retrospective study, 45 eyes of 32 patients undergoing phacoemulsification and IOL implantation after myopic laser in situ keratomileusis or photorefractive keratectomy were enrolled.Corneal power was obtained with a Pentacam and IOL Master.The IOL power was calculated by three methods: EKR, a clinical history and the Haigis-L formula.Final postoperative refraction was measured 1 month after the surgery.The median absolute error (MedAE) and the mean absolute error (MAE) of postoperative refraction were compared with those from the Haigis-L formula and the clinical history.The Kruskal-Wallis test was used to compare MedAE and one-way ANOVA was used for MAE.The accuracy of the EKR method was compared with other popular IOL calculation formulas for use in eyes after LASIK or PRK.Results EKR achieved the greatest predictive accuracy (P＜0.05), with a MedAE of 0.32 D and MAE of 0.39 D.Seventy-one percent of eyes were within ±0.50 D and 93％ were within ±1.00 D of the EKR predicted outcome.This was significantly more accurate than the other preoperative methods: MedAE was 0.51 D and was 1.48 D for the Haigis-L method and the clinical history, respectively.Conclusion The IOL power estimation in challenging eyes with prior LASIK or PRK is most accurately predicted by EKR.