不同公式计算角膜屈光术后白内障患者IOL屈光度的准确性比较

Accuracy comparison of different formulas in calculating intraocular lens power in cataract patients after corneal refractive surgery

摘要:

目的：对比观察5种人工晶状体(IOL)计算公式在角膜屈光术后白内障患者IOL屈光度计算中的准确性。

方法：前瞻性系列病例研究。收集2021-09/2023-03就诊于济南明水眼科医院的既往行角膜屈光手术矫正近视的白内障患者23例34眼，其中准分子角膜切削术(PRK)手术史1例1眼，准分子原位角膜磨镶术(LASIK)术后22例33眼。白内障术前采用IOL Master 700测量眼生物学参数； Pentacam眼前节分析系统测量角膜真实净屈光力(TNP)； 眼前节OCT测量净角膜屈光力(NCP)、角膜后表面屈光力、角膜厚度(CCT)。采用Shammas公式、Haigis-L公式、Potvin-Hill Pentacam公式、OCT公式、Barrett True K公式进行IOL度数计算后综合选择合适的IOL度数。术后1 mo在客观验光的基础上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5种公式的屈光预测误差(RPE)，其绝对值为屈光绝对误差(RAE)，比较RPE与0的差异及不同公式间RPE、RAE的差异，并统计RAE≤0.5 D、≤1.0 D的眼数所占百分比。

结果：5种公式计算所得的RPE与0比较均无差异(均P>0.05)。5种计算公式的RPE、RAE整体无差异(F=0.554，P=0.696； H=4.402，P=0.354)； Potvin-Hill Pentacam公式、Barrett True K公式的RAE在≤0.5 D内的眼占比分别为26眼(76%)、24眼(71%)，在≤1.0 D内的眼占比均为33眼(97%)。

结论：Barrett True K 公式、Potvin-Hill Pentacam公式在角膜屈光术后白内障患者IOL屈光度计算中表现出较高的预测性。由于此类人群角膜屈光力存在差异，IOL度数计算问题仍需要进一步研究，临床上建议多种公式综合考虑。

Abstract:

AIM: To compare and observe the accuracy of five intraocular lens(IOL)power calculation formulas in patients with cataracts who have previously undergone corneal refractive surgery.

METHODS: Prospective case series study. A total of 23 cataract patients(34 eyes)with a history of myopic corneal refractive surgery at Jinan Mingshui Eye Hospital from September 2021 to March 2023 were collected, including 1 eye treated with photorefractive keratectomy(PRK)and 22 patients(33 eyes)treated with laser-assisted in situ keratomileusis(LASIK). Preoperative ocular biometry was performed using the IOL Master 700, while corneal true net refractive power(TNP)was measured via Pentacam analyzer. Anterior segment optical coherence tomography(OCT)was used to assesse net corneal power(NCP), posterior corneal refractive power, and central corneal thickness(CCT). The Shammas, Haigis-L, Potvin-Hill Pentacam, OCT, and Barrett True K formulas were utilized for IOL power calculations, with the optimal power selected accordingly. At 1 mo postoperatively, actual refractive outcomes were determined through subjective refraction, based on objective optometry results. The refractive prediction error(RPE)and refractive absolute error(RAE)of each formula were calculated and compared, and the percentage of eyes with RAE ≤0.5 D and ≤1.0 D was counted.

RESULTS: No significant statistical difference was found in the RPE of the five formulas when compared to zero(all P>0.05), nor were there significant differences in RPE and RAE among the formulas(F=0.554, P=0.696; H=4.402, P=0.354). The RAE was within ≤0.5 D for 26 eyes(76%)using the Potvin-Hill Pentacam formula and for 24 eyes(71%)using the Barrett True K formula, with both formulas achieving an RAE within ≤1.0D in 33 eyes(97%).

CONCLUSIONS: The Barrett True K and Potvin-Hill Pentacam formulas demonstrated high predictive accuracy for IOL power calculations in post-corneal refractive surgery cataract patients. Given the variability in corneal refractive power among these patients, further research on IOL power calculation is warranted. Clinically, it is advisable to consider a range of formulas for optimal outcomes.