应用Pentacam及Haigis公式预测LASIK术后IOL度数研究

To predict the IOL power after LASIK surgery using Pentacam and Haigis formula

目的评估使用Pentacam测量角膜曲率和Haigis人工晶状体计算公式对于Lasik术后预测人工晶状体度数的准确性。方法临床病例分组对照研究。对2008年1月至2009年12月在天津市眼科医院就诊病人，按时间随机选取准分子激光原位角膜磨镶术（LASIK）患者73例103只眼。根据术前近视程度将患者分为3组，即低度近视组（近视≤-3．0D），共5只眼，平均近视（-2．87±0．60）D；中度近视组（近视～≤-6．0D），共42只眼，平均近视（-4．33±0．60）D；高度近视组（近视〉～6．0D），共56只眼，平均近视（-8．75±0．60）D。术后随访1个月。使用Pentacam测量角膜曲率并与临床病史法得出的角膜曲率值比较；使用Haigis公式计算Lasik术后人工晶状体度数，并分别与角膜旁路途径和SRKfF公式计算出的人工晶状体度数进行比较。结果不同近视度组患者使用Pentaeam测量出的角膜曲率值与临床病史法得出的数值进行比较，差异无统计学意义（t值分别为-0．523，-1．189，2．019；P〉0．05）。将所有患者使用Pentacam测量出的角膜曲率值分别带入Haigis公式和SRK／T公式，使用IOLMaster仪器计算人工晶状体度数，并与角膜旁途径法得出的数值进行比较。Haigis公式和SRK／T公式计算出不同近视度组的结果显示差异无统计学意义，但Haigis公式预算的屈光度更接近于术前预测值（f值分别为1．821，1．422，-3．707；P〉0．05）。结论Pentacam可以精确地测量角膜中心区域的前后表面的曲率，该数值可直接应用于IOL计算公式；Haigis公式计算Lasik术后白内障人工晶状体度数具有较好的准确性。

Objective To assess the accuracy of calculating the IOL after LASIK surgery using the Pentacam and Haigis formula. Methods In the prospective randomized clinical controlled study, 103 eyes of 73 patients for LASIK surgery were selected according to the extent of myopia and divided into 3 groups, 5 ：eyes for low myopia （≤-3.0D）, average was （-2.87±0.60）D; 42 eyes for moderate myopia （≤-6.0D）, average was （-4.33±0.60）D; 56 eyes for high myopia （〉-6.0D）, average was （-8.75±0.60）D. Following 1 month after LASIK, compared the corneal curvature using Pentacam with clinical history law; compared the IOL power by Haigis formula with the corneal bypass methods and SRK/T formula. Results There were no obvious difference between the Pentacam and clinical history law about measuring the corneal curvature in the different myopia groups （t = -0.523, -1.189, 2.019; P 〉0.05）. Using the corneal power of Pentacam at 4 mm pupils calculated the IOL power by the Haigis and SRK/T fomula, compared the IOL power with it by corneal bypass methods. There were no statistics differences between the Haigis and SRK/T formulas in the different myopia groups. But the IOL powers calculated by Haigis formula were similar with that by corneal bypass methods （t =1.821, 1.422, -3.707; P 〉0.05）. Conclusions Pentacam can measure the corneal curvature of central 4 mm exactly and the value can be directly applied to calculate IOLpower. Using the Haigis formula to calculate the IOL power is more accurate after the Lasik surgery.