A Comparative Study of Refraction in Skiascopy and Autorefractometry before and after Application of Cycloplegics

Abstract

Purpose: To evaluate the difference of refractive errors measured by skiascopy and autorefractometry before and after application of cycloplegics according to age, the degree of myopia and of astigmatism.Methods: School myopia (384 eyes of 227 persons) were measured by skiascopy and autorefractometry before and after instillation of cycloplegics, and each refractive error was compared. According to age, it was divided into elementary school group (236 eyes), middle and high school group (54 eyes), and university group (94 eyes). Myopic spherical power was classified into mild group with power -2.0 diopter (D) or less (119 eyes), moderate group with -2.0 D or more and -6.0 D or less (178 eyes), and high group with greater than -6.0 D (87 eyes). Astigmatism is divided into mild group with less than -2.0 D (296 eyes) and high group with greater than -2.0 D (88 eyes).Results: The post-cycloplegics spherical and spherical equivalent refractive values by the autorefractometry and the skiascopy were measured to be lower than manifest autorefractometry, and the astigmatic power after cycloplegic refraction was measured to be high, but there is no statistically significant difference (<i>p</i> > 0.05). In the case of elementary school, middle and high school, the value of spherical and astigmatism increased significantly compared to the university group, but there is no statistically significant difference (<i>p</i> > 0.05). The difference of refractive errors between the spherical and the spherical equivalent value increased significantly as the degree of myopia increased. The value of difference between mild and high group of astigmatism was significantly increased in high group compared to mild group.Conclusions: It should be necessary to accurately measure to wear glasses in school myopia with the younger, the more myopia is greater than -6.0 D, and high astigmatism with more than -2.0 D.