高度近视眼人工晶状体度数计算公式的准确性比较

目的　评价用ＩＯＬＭａｓｔｅｒ和ＳＲＫ-Ⅱ、ＳＲＫ-Ｔ、Ｈｏｌｌａｄａｙ-１和Ｈａｉｇｉｓ四种公式计算眼轴≥２７ｍｍ的高度近视眼人工晶状体（ｉｎｔｒａｏｃｕｌａｒｌｅｎｓ，ＩＯＬ）度数的准确性。方法　回顾性分析于我院行白内障超声乳化摘出联合ＩＯＬ植入术、眼轴≥２７ｍｍ的高度近视合并白内障患者１０５例（１４８眼）的临床资料，用ＩＯＬＭａｓｔｅｒ测量并用以上四种公式计算ＩＯＬ度数和预测术后屈光度。按照眼轴长度分组，从２７ｍｍ起每增加１ｍｍ为一组，分别计算各组术后３个月时实际术后等效球镜度（ａｃｔｕａｌｐｏｓｔｏｐｅｒａｔｉｖｅｓｐｈｅｒｉｃａｌｅｑｕｉｖａｌｅｎｃｅ，ＡＰＳＥ）与四种公式计算的预测术后等效球镜度（ｐｒｅｄｉｃｔｅｄｐｏｓｔｏｐｅｒａｔｉｖｅｓｐｈｅｒｉｃａｌｅｑｕｉｖａｌｅｎｃｅ，ＰＰＳＥ）的差值，即为预测屈光度误差值（ｐｒｅｄｉｃｔｉｖｅｅｒｒｏｒ，ＰＥ）。比较四种公式在不同眼轴长度区间ＰＥ的统计学差异，将眼轴组间ＰＥ没有统计学差异的组合并得到眼轴长区间，并计算出这四种ＩＯＬ计算公式在不同眼轴长度区间的ＰＥ。结果　１４８眼眼轴长度为（３１．０６±２．３２）ｍｍ，ＰＥ在ＳＲＫ-Ⅱ、ＳＲＫ-Ｔ、Ｈｏｌｌａｄａｙ-１和Ｈａｉｇｉｓ公式分别为（１．０１±１．５３）Ｄ、（０．７６±０．９６）Ｄ、（１．２４±０．８０）Ｄ和（０．７８±０．８４）Ｄ；四种公式计算的ＰＰＳＥ与ＡＰＳＥ间差异均有统计学意义（均为Ｐ＜０．０５），ＳＲＫ-Ｔ和Ｈａｉｇｉｓ公式的ＰＥ差异无统计学意义（Ｐ＞０．０５）；Ｈｏｌｌａｄａｙ-１公式的ＰＥ与ＳＲＫ-Ｔ、Ｈａｉｇｉｓ公式的ＰＥ均有显著差异（均为Ｐ＜０．０５）。将眼轴组间ＰＥ没有统计学差异的组合并后得到２７～３０ｍｍ、３０～３２ｍｍ、３２～３４ｍｍ、≥３４ｍｍ四个眼轴长度区间，ＳＲＫ-Ｔ／Ｈａｉｇｉｓ公式在各区间的ＰＥ分别为（０．２１±０．６５）Ｄ／（０．４８±０．７１）Ｄ、（０．５８±０．５６）Ｄ／（０．５８±０．６１）Ｄ、（１．１８±０．６７）Ｄ／（０．９７±０．６１）Ｄ和（１．９７±１．４４）Ｄ／（１．７６±１．２６）Ｄ。结论　在眼轴≥２７ｍｍ的高度近视眼ＩＯＬ度数计算上ＳＲＫ-Ⅱ、ＳＲＫ-Ｔ、Ｈａｉｇｉｓ和Ｈｏｌｌａｄａｙ-１公式预测术后屈光度均为近视方向的过矫正。在不同眼轴长度区间用ＳＲＫ-Ｔ／Ｈａｉｇｉｓ公式计算时，适当向近视方向调整ＰＰＳＥ（－０．２～－２．０）／（－０．５～－１．８）Ｄ而得到的植入ＩＯＬ度数可以改善计算公式的准确性。

Accuracy of intraocular lens power calculation formulas in eyes with high axial myopia

Objective To evaluate the accuracy of intraocular lens (IOL) power calculations using IOL Master and four different IOL calculation formulas ( SRK- II . SRK-T,Holladay-I and Haigis) in myopic eyes with axial lengths of 27 mm or more. Methods This retrospective study reviewed 105 patients ( 148 eyes) with high myopia and axial lengths of 27 mm or more who had cataract surgery from July 2010 to October 2013 in our hospital. In each case, the power of implanted IOL was calculated by IOL Master and four IOL power calculation formulas : SRK- II , SRK-T, Holladay-I and Haigis. The cases were divided into different groups according to axial length. With I mm adding in axial length between 27 mm and 34 mm , each group was set. The actual postoperative diopters were spherical equivalent diopters ( actual postoperative spherical equivalence ,APSE) , which was measured at about 3 months after surgery. The predicted postoperative spherical equivalence ( PPSE) was calculated by four IOL power calculation formulas. The predictive error ( PE) of the formulas was analyzed by comparing the difference between the actual and predicted postoperative refractive diopters. The axial groups with no statistical differences of PE were combined, and mean PE of combined groups were evaluated. Results The axial length was ( 3 1. 06 + 2. 32 ) mm. PE calculated with SRK II.SRK/T,Holladay-I and Haigis formulas was ( 1. 01 + 1. 53 ) D, ( 0. 76 + 0. 96 ) D , ( 1. 24 + 0. 80 ) D . and ( 0. 78 + 0. 84 ) D , respectively , statistical differences were showed between APSE and PPSE with four IOL calculation formulas ( all P < 0. 05 ) . Calculating with SRK-T and Haigis fomulas. PE were relatively small and no statistical difference was found between them ( P > 0. 05 ) . Calculating with Holladay-I formula , PE was the largest in four formulas , and statistical differences were found among Holladay-I , SRK-T , Haigis formulas ( all P < 0. 05 ) . After evaluating no differences of PE among axial groups , the groups were combined and reformed four axial intervals :27 - 30 mm .30 - 32 mm .32 - 34 mm . and longer than 34 mm. Calculating with SRK-T or Haigis formulas in these axial intervals. PE were (0. 21 + 0. 65 ) D/( 0. 48 + 0. 71 ) D. ( 0. 58 +0. 56) D/( 0. 58 +0. 61 ) D. ( 1. 18 +0. 67 ) D/(O. 97 +0. 61) D.and ( 1. 97 + 1. 44 ) D/( 1. 76 + 1. 26 ) D, respectively. Conclusion In eyes with axial lengths of 27 mm or more ,SRK- II .SRK-T,Holladay-l and Haigis formulas have a tendency to over minus diopter. The predictability of SRK-T or Haigis formula appear to be improved by adjusting PPSE ( - 0. 2 - - 2. 0) D/( - 0. 5 - - 1. 8 ) D and therefore obtairung the power of implanted IOL in different axial intervals.