Astigmatism analysis by the Alpins method
Astigmatism analysis by the Alpins method
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DOI：
10.1016/s0886-3350(00)00798-7
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发表时间：
2001-01-01
影响因子：
2.8
通讯作者：
Alpins, N
中科院分区：
文献类型：
--
作者：
Alpins, N
目的：通过使用3个基本矢量的矢量散光结果分析确定激光屈光手术矫正散光的有效性：目标诱导散光矢量（TIA（R））、手术诱导散光矢量和差异矢量，如Alpins方法所述。100眼激光原位角膜磨镶术矫正近视散光的数据集（最小术前屈光散光0.75屈光度）进行了分析。数据包括术前和术后3个月的明显屈光和标准角膜曲率值。使用ASSORT（R）或VectrAK（R）分析程序，通过散光的简单、极坐标和矢量分析以及球面变化分析进行个体和总体数据分析。统计分析的结果被用于平均值和置信限，以及检查角膜和屈光散光outcomes.Results之间的差异：在个别患者的水平，错误的角度被发现是显着的，这表明在工作中的变量因素，如愈合或对齐。在这100名患者的治疗中，散光矫正不足的系统误差普遍存在，其系数在15%和30%之间，这取决于是否检查屈光或角膜值。球面校正显示系统欠矫11%，平行指数证明它是更有效的比admatic correction.Conclusion：这种方法的散光分析，使检查结果散光治疗测量的屈光度和角膜测量使用矢量分析。通过检查个体向量与TIA的关系（即矫正指数、成功指数和扁平指数），完成了全面的散光分析。每个索引提供了理解任何化学变化所需的信息。散光结果参数更有利时，测量主观屈光比客观角膜的方法。
Purpose: To determine the effectiveness of correcting astigmatism by laser refractive surgery by a vectorial astigmatism outcome analysis that uses 3 fundamental vectors: target induced astigmatism vector (TIA(R)), surgically induced astigmatism vector, and difference vector, as described by the Alpins method.Methods: A data set of 100 eyes that had laser in situ keratomileusis to correct myopia and astigmatism (minimum preoperative refractive astigmatism 0.75 diopter) was analyzed. The data included preoperative and 3 month postoperative values for manifest refraction and standard keratometry. Using the ASSORT(R) or VectrAK(R) analysis program, individual and aggregate data analyses were performed using simple, polar, and vector analysis of astigmatism and an analysis of spherical change. Statistical analysis of the results was used for means and confidence limits, as well as to examine the differences between corneal and refractive astigmatism outcomes.Results: At an individual patient level, the angle of error was found to be significant, suggesting variable factors at work, such as healing or alignment. A systematic error of undercorrection of astigmatism is prevalent in the treatment of these 100 patients by a factor of between 15% and 30%, depending on whether refractive or corneal values are examined. Spherical correction showed systematic undercorrection of 11%, and parallel indices demonstrated it to be more effective than the astigmatic correction.Conclusion: This method of astigmatism analysis enables the examination of results of astigmatism treatment measured by both refractive and corneal measurements using vector analysis. By examining individual vector relationships to the TIA (ie, the correction index, index of success, and flattening index), a comprehensive astigmatism analysis is completed. Each index provides information necessary for understanding any astigmatic change. Astigmatic outcome parameters are more favorable when measured by subjective refractive than objective corneal methods.