Ninomiy Yoshihiko, Kanazawa Yayoi, Kojima Yoshinao, Maeda Naoyuki
Department of Ophthalmology, Yukioka Hospital, 2-2-3 Ukida, Kita-ku, Osaka 530-0021, Japan.
Nippon Ganka Gakkai Zasshi. 2013 Aug;117(8):621-8.
To study the repeatability and scale increments of automated keratometry and their influence on the use of the toric intraocular lens (IOL) and on astigmatism correction.
The study enrolled 131 eyes of 82 patients. Preoperative corneal astigmatism was measured in the different (0.01D and 0.25D) scale increment setting of automated keratometer on separate days. An arithmetic astigmatism in 0.25 D scale increment was also calculated from that of 0.01 D scale increment. These three types of corneal astigmatism were comparatively appraised with a web-based calculator, evaluating indication and style selection of the toric IOL and simulated residual astigmatism.
Different scale increments caused no significant difference in simulated residual astigmatism. The repeatability of calculated IOL style selection and axis location was low in eyes with mild astigmatism. True standard deviation of test-retest discrepancy in the size of corneal astigmatism was 0.293 D.
In mild astigmatism, the effectuation of the toric IOL, such as IOL style selection and axis location, was ineffective. However, the scale increment of 0.25 D presented moderate sensitivity. The refinement of corneal astigmatism measurement and development of algorithm would be the key to more accurate astigmatism correction with a toric IOL implantation.
研究自动角膜曲率计的重复性和测量范围增量及其对散光型人工晶状体（IOL）使用和散光矫正的影响。
该研究纳入了82例患者的131只眼。在不同日期，于自动角膜曲率计不同的（0.01D和0.25D）测量范围增量设置下测量术前角膜散光。还从0.01D测量范围增量的角膜散光计算出0.25D测量范围增量的算术散光。使用基于网络的计算器对这三种类型的角膜散光进行比较评估，评估散光型IOL的适应证和型号选择以及模拟残余散光。
不同的测量范围增量在模拟残余散光方面无显著差异。轻度散光眼中计算的IOL型号选择和轴位定位的重复性较低。角膜散光大小的重测差异的真实标准差为0.293D。
在轻度散光中，散光型IOL的实施，如IOL型号选择和轴位定位，效果不佳。然而，0.25D的测量范围增量具有中等敏感性。角膜散光测量的精细化和算法的开发将是通过植入散光型IOL实现更精确散光矫正的关键。
