不同群体角膜前表面非球性系数测量结果分析

Analysis of measurement results of anterior corneal asphericity of different groups

目的:分别测量近视眼及白内障两组患者角膜前表面非球性系数(Q值),探讨可能的相关因素。方法:近视眼患者240例,按屈光度分为高、中、低三组,性别比例基本匹配,年龄为18~32岁,随机选择其中48例配戴角膜接触镜的患者分别测量摘镜后第1,15d的Q值;白内障患者123例,年龄42~80岁。常规进行角膜地形图、综合验光、角膜中央厚度等检查,对各项检查结果进行分析。结果:近视眼组其Q值范围为-0.62^-0.04,平均为-0.296;白内障组其Q值范围为-0.67^-0.01,平均为-0.232,白内障患者的Q值低于近视眼患者的Q值,差异有统计学意义(P=0.00);近视眼的Q值女性高于男性,差异有统计学意义(P=0.00);Q值与屈光度相关性分析显示无明显相关,高、中、低三组间差异没有统计学意义;近视眼组同一个体左右眼Q值、隐形眼镜脱镜后第1,15dQ值分布线性关系显著,但差异均无统计学意义。结论:Q值是表示角膜最平坦子午线角膜变陡或变平的程度表面形状系数。近视眼及白内障患者两个群体角膜Q值均呈正态分布,两组数值分布差异有统计学意义;Q值与角膜曲率、屈光度、角膜厚度无明显相关,配戴角膜接触镜对Q值的测量结果无影响。

AIM： To explore some possible relative factors through measuring the anterior corneal asphericity factor Q in cataract and myopic eyes respectively. METHODS： A total of 240 myopia cases aged 18-32 with an idea sex ratio, were divided into high, moderate and low groups. Also 48 corneal contact lens （CCL） wearers were randomly chosen from myopia group, Their 1st and 15th day＇s Q value were measured after taking off lens. Totally 123 cases aged 42-80 were included in cataract group. Both myopia and cataract groups were received some routine check like corneal topography, subject refraction and central corneal thickness measurement and the results were analyzed. RESULTS ： Q value was - 0.62 ~ - 0.04 with an average value of - 0. 296 in myopia group and - 0.67 ~ - 0.01 with an average value of - 0. 232 in cataract group. Q value of senile cataract was lower than that of the myopia, the difference showed statistical significance （ P = 0. 00）. Female＇s Q value was higher than male＇s, which showed statistical significance （ P = 0. 00）. No significant linear correlation was found between Q value and diopter, and the difference among the three groups had no statistical significance. There was no statistical difference between 2 eyes of each subject from myopia group and the Q value of their 1= and 15th day after taking off CCL, though the two values indicated significant linear correlation. CONCLUSION ： Q value is a shape factor to indicate the degree of steepness of the flattest meridians on corneal surface. Both Q values in myopia and in cataract group show normal distribution. And the distribution difference between the two groups had statistical significance. Qvalue has no correlation with cornea curvature, diopter and cornea thickness. CCL wearing is no interference to the results.