7～12岁儿童近视程度与AL/CR值的关系

Relationship between myopia and AL/CR ratio in children of 7-12 years old

摘要:

目的：探讨7～12岁儿童眼轴长度/角膜曲率半径比值（axis length/corneal radius of curvature ratio，AL/CR值）与近视程度的关系。方法：通过睫状肌麻痹检影验光及光学生物测量仪（IOL-Master）获得7～12岁儿童402例（804只眼）的等效球镜度、眼轴长度、角膜屈光力，并计算AL/CR值。按等效球镜度分为轻度近视、中度近视及高度近视3组，采用SPSS 22.0统计学软件进行数据统计。结果：高度近视组AL/CR值（3.47±0.13）与中度近视组（3.26±0.09）、轻度近视组（3.12±0.07）比较差异有统计学意义（F=972.220，P=0.000）。等效球镜度与AL/CR值相关性高于眼轴长度及角膜曲率半径（r=-0.886，r=-0.752，r=0.243，P=0.000），线性回归显示AL/CR值每增加1个单位，等效球镜度向近视方向变化约15.2D（r2=78.4%，P=0.000）。轻度近视、中度近视及高度近视组中，眼轴长度与角膜曲率半径的线性回归直线差异有统计学意义（r2=48.1%，r2=50.9%，r2=16.7%，P=0.000），AL/CR值与等效球镜度的线性回归直线差异有统计学意义（r2=20.5%，r2=19.5%，r2=84.0%，P=0.000）。结论：AL/CR值是判断近视的一项客观指标，可用于不同程度近视的分类。

Abstract:

Objective：To investigate the relationship between axis length/corneal radius of curvature ratio（AL/CR ratio） and myopia degree in children of 7-12years old. Methods：Data of spherical equivalent refraction，axial length and corneal refractive power from 402 children（804 eyes） of 7-12 years old were obtained by cycloplegic optometry and IOL-Master and AL/CR ratio was calculated. According to the spherical equivalent refraction，402 children were divided into three groups：mild myopia group，moderate myopia group and high myopia group. Statistics were analyzed by SPSS 22.0 software. Results：AL/CR ratio among high myopia group（3.47±0.13），moderate myopia group（3.26±0.09） and mild myopia group（3.12±0.07） was significantly different（F=972.220，P=0.000）. Correlation between spherical equivalent refraction and AL/CR ratio was higher than that between axial length and corneal radius of curvature（r=-0.886，r=-0.752，r=0.243，P=0.000）. According to the linear regression，spherical equivalent refraction was changed about-15.2D with each increase of AL/CR ratio（r2=78.4%，P=0.000）. Among those three groups，difference of linear regression line between axial length and corneal radius of curvature had no statistical significance（r2=48.1%，r2=50.9%，r2=16.7%，P=0.000），but dif－ference of the linear regression line between AL/CR ratio and spherical equivalent refraction had statistical significance（r2=20.5%，r2=19.5%，r2=84.0%，P=0.000）. Conclusion：AL/CR ratio is an objective index in the diagnosis of myopia and can be used to clas－sify different degrees of myopia.