角膜屈光手术后人工晶状体度数计算的初步研究

摘要

Objective To evaluate the results of cataract surgery in myopia patients after laser in situ keratomileusis(LASIK)and to compare the predictability of various methods of intraccular lens(IOL)power calculation.Method Seventeen cases (24 eyes)who had LASIK for myopia were divided into two group by with or without history of corneal power data.Corneal power was obtained by autokeratometry,corneal topography.Pentacam and IOLMaster.The IOL power was calculated with the clinical history method,Feiz-Mannis formula,Feiz-Mannis method and other methods.Postoperative final refraction and the deviation of the final spherical equivalent (SEQ) from the refractive target were measured 3 month after the surgery.Two sample t-test.linear correlation and regression analysis,paired t-test and Bland-Altman method of agreement were used to analyze these data.Results In the group with history data,the mean corneal power was(43.28±1.21)D and the mean SEQ was(-15.33±4.36)D before the LASIK surgery.In the group without history data,the mean SEQ was(-10.11±3.12)D.Before cataract surgery,the mean corneal power was(36.96±2.07)D and(36.85±1.40)D in these two groups.The mean arithmetic refractive prediction error after cataract surgery was(-0.66±1.27)D and(-0.47 ± 0.82)D in these two groups, respectively. Data calculated by using Hamed-Wang-Koch method, Masket Formula, Koch/Maloney method, Shammar method and Pentacam ERK method were lower than the emmetropic IOL power. Data calculated by using Feiz-Mannis Formula, Latkany Method, Savini method, Armberri Double K method were overestimated. The mean arithmetic errors of clinic history method, Corneal Passby Method and Haigis-L Formula were not significantly different from the predict refraction (P=0. 364, 0. 318 and 0. 069;t=0. 956,-1. 057 and -1. 911, respectively). There was strong correlation between the value calculated by using Feiz-Mannis Method or Haigis-L Formula and the true power (r = 0. 921,0. 915; P = 0. 000 and 0. 000,respectively). But none of the values calculated by these method could fully agree with the true value.Conclusions IOL power should be calculated accurately to avoid undercorrection. We recommend the combination of clinical history method, Feiz-Mannis Method, Corneal Passby Method and Haigis-L Formula for the calculation of IOL power.%目的 对准分子激光角膜屈光手术后的白内障患者,分析其超声乳化白内障吸除联合人工晶状体(IOL)植入术后的屈光状态以及各种IOL度数计算方法的准确性.方法 回顾性系列病例研究.17例(24只眼)患者根据是否提供准分子激光术前(包括准分子激光角膜切削术和准分子激光角膜原位磨镶术)角膜屈光度数资料分为两组(有历史资料组和无历史资料组).所有患者在白内障术前接受自动角膜曲率计、角膜地形图、Pentacam、IOL Master综合检查,分别采用临床病史法、Feiz-Mannis公式法、Feiz-Mannis法等多种公式进行IOL度数计算.白内障术后3个月时进行客观验光.采用非配对t检验,Pearson相关分析及线性回归分析,配对t检验以及Bland-Ahman一致性检验对数据进行分析.结果 有历史资料组患者准分子激光术前的平均屈光度数与平均等效球镜分别为(43.28±1.21)D与(-15.33±4.36)D;无历史资料组的平均等效球镜为(-10.11±3.12)D.白内障术前两组平均角膜屈光度数为(36.96 ± 2.07)D与(36.85±1.40)D.白内障术后两组平均屈光误差分别为(-0.66±1.27)D与(-0.47 ± 0.82)D.Hamed Wang Koch法、Masket法、Koch/Maloney法、Shammar法与Pentacam ERK法计算值低于平均真实值,易造成术后欠矫;Feiz-Mannis公式法、Latkany法、Savini法与Armberri Double K的计算值高于真实值.临床病史法,角膜忽略法和Haigis-L法的计算值与真实值之间差异无统计学意义(P=0.364,0.318,0.069;t=0.956,-1.057,-1.911).Feiz-Mannis法和Haigis-L法计算结果与真实值之间具有一定相关性(r=0.921,0.915;P=0.000,0.000).但无一种方法计算结果与真实值具有一致性.结论 为避免术后发生屈光欠矫,需要通过综合方法计算IOL度数,应联合临床病史法、Feiz-Mannis法、角膜忽略法、Haigis-L法进行IOL度数计算.