Purpose

Astigmatism is a highly prevalent refractive error and while studies typically focus to describe the axis symmetry between eyes, little is known about the refractive symmetry. Therefore, this study determined the astigmatic power symmetry between eyes in a large clinic population.

Methods

A clinical chart review was conducted at three optometric practices in the United States, the United Kingdom and Canada and subjective refraction data from 88,891 patients 14–70 years of age who presented with at least −0.25DC refractive astigmatism in at least one eye were included in the analysis. Data were obtained at these practices between January 2014 and March 2017. The overall distribution (%) and magnitude (DC) of astigmatism was determined and refractive differences between eyes were identified.

Results

The mean age of the patients was 42.1 ± 15.9 years and included 51,685 (58%) female and 37,206 (42%) male patients. In this data pool of 177,782 eyes, 10.9% required zero astigmatic correction, while 56.2% had astigmatism of −0.25 to −0.75DC. In total 23.9% of patients presented with astigmatism of at least −0.75DC in only one eye, while the other eye had 0 to −0.50DC. Overall, the difference in astigmatism between eyes was less than −0.75DC for 82.1% of astigmatic patients. For patients who presented with astigmatism of −1.00DC in the right eye, 80.8% of them had an astigmatic prescription of −1.00 ± 0.50DC in the left eye. For an astigmatic prescription of −4.00DC in the right eye, only 40.6% of patients exhibited astigmatism of −4.00DC ± 0.50DC in the left eye.

Conclusions

The majority of patients exhibited a difference in astigmatism between eyes of less than −0.75DC, however the refractive cylinder power symmetry was significantly lower in patients with higher refractive astigmatism.

中文翻译：

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散光的大小 - 眼睛之间的比较

目的

散光是一种非常普遍的屈光不正，虽然研究通常集中描述眼睛之间的轴对称性，但对屈光对称性知之甚少。因此，本研究确定了大型诊所人群中眼睛之间的散光度数对称性。

方法

在美国、英国和加拿大的三个验光诊所进行了临床图表审查，并纳入了 88,891 名 14-70 岁患者的主观屈光数据，这些患者至少一只眼睛出现至少 -0.25DC 屈光散光在分析中。在 2014 年 1 月至 2017 年 3 月期间在这些实践中获得了数据。确定了散光的总体分布 (%) 和幅度 (DC)，并确定了眼睛之间的屈光差异。

结果

患者的平均年龄为 42.1 ± 15.9 岁，包括 51,685 (58%) 名女性和 37,206 (42%) 名男性患者。在这个 177,782 只眼睛的数据池中，10.9% 需要零散光矫正，而 56.2% 的散光为 -0.25 至 -0.75DC。总共有 23.9% 的患者仅一只眼出现至少 -0.75DC 的散光，而另一只眼的散光为 0 至 -0.50DC。总体而言，82.1% 的散光患者眼睛之间的散光差异小于 -0.75DC。对于右眼散光度数为-1.00DC 的患者，80.8% 的患者左眼散光度数为-1.00 ± 0.50DC。对于右眼 -4.00DC 的散光处方，只有 40.6% 的患者在左眼表现出 -4.00DC ± 0.50DC 的散光。

结论

大多数患者的眼睛之间的散光差异小于-0.75DC，但是屈光度较高的散光患者的屈光圆柱度数对称性显着降低。