近视散光患者角膜前、后表面Q值的测量分析

Q-value of the antierior and posterior cornea surface in myopic astigmatic patients

目的探讨青年近视眼患者角膜前后表面的非球面性(Q值)变化规律。设计前瞻性病例系列。研究对象2009年1月至2011年1月在北京同仁医院接受LASIK手术的青年近视散光患者423例(829眼)。方法采用Oculyzer眼前节诊断系统对所有近视散光患者进行检测,获得角膜Q值进行统计学分析。主要指标Q值、屈光度、角膜屈光力。结果角膜前表面Q20、Q25、Q30、Q35、Q40分别为(-0.24±0.13)、(-0.28±0.12)、(-0.31±0.12)、(-0.36±0.13)、(-0.35±0.28);角膜后表面分别为(0.21±0.25)、(0.05±0.21)、(-0.09±0.19)、(-0.21±0.16)、(-0.31±0.14);各项Q值呈正态分布。角膜前表面各项Q值与柱镜度和角膜前表面散光均呈负相关(P<0.05);角膜前表面Q20、Q25、Q30、Q40和角膜前表面陡峭方向屈光力呈负相关(P<0.05)。角膜后表面各项Q值与球镜度和等效球镜度呈正相关(P均<0.05)。角膜前表面Q25、Q30与患者年龄呈正相关(P均<0.05),角膜后表面各项Q值与眼压呈负相关(P均<0.05),角膜前后表面各项Q值与角膜厚度不相关。结论大多数青年近视散光患者角膜形态前表面为长椭圆形,后表面中央为扁椭圆形,周边为长椭圆形。

Objective To investigate the change of the anterior and posterior corneal surface asphericity（Q-value） of young myopia.Design Prospective case series.Participants 829 eyes of 423 young patients with myopia.Main Outcome Measures Q-values,diopter,corneal refrective power.Methods All patients were examined by Oculyzer,and Q-values were analyzed.Results The Q20,Q25,Q30,Q35 and Q40 of the corneal anterior surface were-0.24±0.13,-0.28±0.12,-0.31±0.12,-0.36±0.13,-0.35±0.28 respectively.The values of posterior corneal surface were 0.21±0.25,0.05±0.21,-0.09±0.19,-0.21±0.16,-0.31±0.14 respectively.They all showed normal distribution.The Q-values of the anterior corneal surface was negatively associated with cylinder diopter（CD） and corneal astigmatism（CA）（P0.05）.The Q20,Q25,Q30 and Q40 of the corneal front surface was negatively associated with anterior steep keratoscope reading（Ks）（P0.05）.The Q-values of the posterior corneal surface was positively associated with spherical diopter（SD） and spherical equivalent（SE）（P0.05）.The Q25 and Q30 of anterior cornea surface was positively associated with age（P0.05）.The Q-values of the posterior corneal surface was negatively associated with intraocular pressure（IOP）（P0.05）.The Q-values of the anterior and posterior corneal surface was not significantly associated with corneal thickness（CT）（P0.05）.Conclusion The anterior corneal surface of most young myopic astigmatic patients is prolate.The central part of posterior corneal surface is oblate,and the periphery part is prolate.