改良SRK-T公式预测人工晶状体植入术后散光误差分析

Error prediction analysis of astigmatism after intraocular lenses implantation with modifiedSRK-T

目的 评价改良SRK-T公式对球面人工晶状体植入术后预测散光的可行性及其误差的影响因素,以探讨改良SRK-T公式在散光人工晶状体度数计算中的应用价值.方法 回顾性系列病例研究.分析2007年10月至2008年6月行超声乳化白内障摘除联合球面人工晶状体植入术且资料完整的白内障病例68例（106眼）.比较改良SRK-T公式与SRK-T公式计算得出的术后预测等效屈光度数之间的差异.矢量分析改良SRK-T公式预测的术后散光度与实际术后散光度之间的差异,并采用多元线性回归分析其影响因素.结果 改良SRK-T公式与SRK-T公式计算得出的术后预测等效屈光度结果完全吻合.矢量分析术后散光预测误差结果示：J0预测误差的因素主要是角膜散光（KS）,J0=-0.108-0.102×KS（P＝0.034）.J45预测误差的因素主要是眼轴（L）与角膜平均屈光度（K）,J45=1.797-0.019×L-0.031×K（P=0.009）.结论 改良SRK-T公式的方法可以用于散光人工晶状体植入度数的计算,其误差跟角膜散光、眼轴、角膜平均屈光度有关.

Objective To evaluate the feasibility and the factors of prediction error of astigmatism after intraocular lens （IOL） implantation by modified SRK-T, and to study the value of modified SRK-T using for toric intraocular lens power calculation. Methods Retrospective case seriesstudy. This study included 68 patients （106 eyes） underwent phacoemulsification during Oct 2007 to June 2008 in Eye hospital of Wenzhou Medical College. The result of the spherical equivalent calculated by SRK-T and modified SRK-T was compared, and the astigmatism error predicted by modified SRK-T and subjective refraction was compared with vector analysis. Influencing factor of modified SRK-T was analyzed with a multivariate linear regression analysis. Results Spherical equivalent calculated by modified SRK-T and SRK-T was equal. The factors of prediction error in J0 was astigmatism of cornea （KS）,J0=-0.108-0.102×KS （P=0.034）; and in J45 was axial length （L） and average refraction of cornea （K）,J45=1.797-0.019×L-0.031×K （P=0.009）. Conclusion Modified SRK-T is a good option for toric intraocular lens power calculation. The influencing factors of prediction include Ks, L and K.