Olsen T, Dam-Johansen M, Bek T, Hjortdal J O
Department of Ophthalmology, Aarhus Kommunehospital, Aarhus University, Denmark.
J Cataract Refract Surg. 1996 Apr;22(3):318-23. doi: 10.1016/s0886-3350(96)80243-4.
To evaluate surgically induced astigmatism using Fourier harmonic series analysis of corneal topography data.
Aarhus Kommunehospital, Aarhus University, Denmark.
We evaluated the results of 46 phacoemulsifications with a 4 or 6 mm scleral tunnel sutureless incision based on the axis of the steepest meridian. We performed conventional keratometry and corneal topography before and up to 1 month after surgery. Using Fourier analysis, the corneal topographic images were broken into spherical power, regular astigmatism, and nonregular astigmatism for individual or aggregate analysis of surgically induced astigmatism. The induced refractive change (average of the difference between preoperative and postoperative corneal topographies) was analyzed and normalized according to the surgical meridian and to right/left eye.
Regular astigmatism calculated by Fourier analysis of mires from the keratometer zone correlated well with conventional keratometry readings. Surgery induced a localized flattening in the superior region and a with-the-rule regular astigmatism component in the central area.
Surgically induced corneal topography changes can be analyzed by Fourier series harmonic analysis, allowing aggregate data to be broken into optically meaningful quantities.
使用角膜地形图数据的傅里叶谐波分析来评估手术引起的散光。
丹麦奥胡斯大学奥胡斯市立医院。
我们基于最陡子午线的轴评估了46例采用4或6毫米巩膜隧道无缝合切口的超声乳化手术的结果。我们在手术前及术后长达1个月进行了常规角膜曲率测量和角膜地形图检查。使用傅里叶分析，将角膜地形图图像分解为球镜度、规则散光和不规则散光，以对手术引起的散光进行个体或总体分析。根据手术子午线和右眼/左眼对诱导的屈光变化（术前和术后角膜地形图之间差异的平均值）进行分析和归一化。
通过角膜曲率计区域的视标进行傅里叶分析计算出的规则散光与常规角膜曲率测量读数相关性良好。手术导致上方区域局部变平，并在中央区域产生顺规性规则散光成分。
手术引起的角膜地形图变化可通过傅里叶级数谐波分析进行分析，从而使总体数据能够分解为具有光学意义的量。
