J Refract Surg. 2021 Apr;37(4):231-239. doi: 10.3928/1081597X-20210114-02. Epub 2021 Apr 1.
To evaluate a ray-tracing formula for intraocular lens (IOL) calculation of diffractive extended depth of focus IOLs after myopic laser in situ keratomileusis (LASIK) compared to formulas from an established online calculator.
This retrospective, consecutive case series included patients after cataract surgery with implantation of an extended depth of focus (EDOF) IOL (AT LARA, Carl Zeiss Meditec; Symfony, Johnson & Johnson) and a history of myopic LASIK. Preoperative assessments included biometry (IOLMaster; Carl Zeiss Meditec) and corneal tomography, including true net power (TNP) (Pentacam; Oculus Optikgeräte GmbH). To evaluate the measurements, the simulated keratometry values (SimK) were compared to the TNP. Regarding IOL calculation, the mean prediction error, mean and median absolute prediction error (MAE and MedAE), and number of eyes within ±0.50, ±1.00, and ±2.00 diopters (D) from the Haigis-L, Shammas, and Barrett True K No History formulas to the Potvin-Hill and Haigis with TNP (Pentacam) formulas were compared.
Thirty-six eyes matched the inclusion criteria with a mean spherical equivalent of -6.26 ± 3.25 diopters (D) preoperatively and -0.79 ± 0.75 D postoperatively. The mean difference from SimK and TNP was significantly different from zero ( < .001; -1.24 ± 0.81 D). The best performing formulas by MedAE were the Potvin-Hill and Barrett True K No History (0.39 ± 0.78 and 0.64 ± 1.00 D). The formula with the most eyes within ±0.50 D was the Potvin-Hill (64%), followed by the Barrett True K No History (44%). For MAE and percentage of eyes within ±0.50 D, the Potvin-Hill formula was significantly better than the Haigis-L, Shammas, and Haigis-TNP formulas ( < .05).
Calculation of IOLs in patients who had LASIK remains less predicable than calculations for virgin eyes. Using ray-tracing to calculate diffractive EDOF IOLs after myopic LASIK, the Potvin-Hill formula outperformed established formulas in terms of the percentage within target refraction and the MAE. .
评估一种用于计算近视激光原位角膜磨镶术（LASIK）后折射性扩展景深人工晶状体（IOL）的光线追踪公式，与一种已建立的在线计算器的公式进行比较。
本回顾性连续病例系列纳入了白内障手术后植入扩展景深（EDOF）IOL（AT LARA，卡尔蔡司 Meditec；Symfony，强生）且有近视 LASIK 病史的患者。术前评估包括生物测量学（IOLMaster；卡尔蔡司 Meditec）和角膜断层扫描，包括真实净力（TNP）（Pentacam；Oculus Optikgeräte GmbH）。为了评估测量结果，模拟角膜曲率值（SimK）与 TNP 进行了比较。关于 IOL 计算，比较了平均预测误差、平均和中位数绝对预测误差（MAE 和 MedAE），以及 Haigis-L、Shammas 和 Barrett True K No History 公式到 Potvin-Hill 和 Haigis 与 TNP（Pentacam）公式的预测值与 0.50、1.00 和 2.00 屈光度（D）的眼数。
36 只眼睛符合纳入标准，术前平均等效球镜度为-6.26 ± 3.25 D，术后为-0.79 ± 0.75 D。SimK 和 TNP 的平均差值与零有显著差异（<0.001；-1.24 ± 0.81 D）。MAE 和 MedAE 表现最好的公式是 Potvin-Hill 和 Barrett True K No History（0.39 ± 0.78 和 0.64 ± 1.00 D）。预测值在±0.50 D 以内的眼数最多的公式是 Potvin-Hill（64%），其次是 Barrett True K No History（44%）。对于 MAE 和预测值在±0.50 D 以内的眼数百分比，Potvin-Hill 公式明显优于 Haigis-L、Shammas 和 Haigis-TNP 公式（<0.05）。
计算 LASIK 后的 IOL 比计算正常眼的 IOL 预测性差。对于近视 LASIK 后折射性 EDOF IOL 的计算，使用光线追踪法，Potvin-Hill 公式在目标屈光度内的百分比和 MAE 方面优于已建立的公式。
