【摘要】 目的研究角膜的非球面参数Q值在不同程度近视眼中的分布及其相关因素。方法165例325只近视眼,按照等效球镜度分为低、中、高度近视3组,低度72眼,中度153眼,高度100眼。采用Allegretto wave topolyzer角膜地形图仪检测近视眼角膜地形图,获取角膜曲率值;overview显示模式获取角膜散光△K值;根据Indices显示获得30°直径范围内的角膜平均偏心率(ε)计算平均Q值(Q=-ε?ε?)。对Q值的分布及其与屈光度、角膜曲率、角膜散光、眼轴长度、角膜中央厚度和眼压等因素的相关性进行统计学分析。结果165例325只近视眼角膜Q值呈正态分布,平均-0.30±0.10(-0.62~-0.04)。低、中、高度近视3组间Q值比较无统计学意义;对各组间Q值进行两两比较,Q值差异均无统计学意义。Q值与角膜曲率呈负线性相关关系;与角膜散光之间呈正线性相关关系;与眼轴长度、角膜中央厚度、眼压之间无相关性。结论角膜非球面参数Q值个体间差异较大,与近视程度无关,在眼光学系统中不是一个独立的参数,与角膜曲率、角膜散光等因素均有相关性。在准分子激光屈光手术中应当针对个体角膜的Q值进行修正,进行个体化切削。更多还原

【Abstract】 Aim To investigate the distribution characters and related factors of corneal asphericity(Q-value) in myopia.Methods According to spherical equivalent(SE),subjects were divided into low myopic group,moderate myopic group and high myopic group.Corneal curvature radius,corneal astigmatism,and corneal eccentricity(ε) within 30°and average vertex of cornea were examined on 165 myopic patients(325 eyes) by ALLEGRO topolyzer,then Q-value(Q=-ε∣ε∣) was calculated.Statistical analysis was used to comprehend the distribution characters of Q-value and its relations with diopter,corneal curvature,corneal astigmatism,length of axis oculi,central corneal thickness and intraocular pressure.Results The Q-value of 325 eyes(165 cases) were positive normal distribution with average-0.30±0.10(-0.62～-0.04).There were no significant differences in Q-value among low myopic,moderate myopic and high myopic groups.The Q-value was negatively related with corneal curvature radius,and positively related with corneal astigmatism.However,it had no relationship with length of axis oculi central corneal thickness and intraocular pressure.Conclusion The corneal Q-value shows a significant individual variation,and is independent from myopic diopter.It is not an absolute parameter,but related with many factors of eye.And the custom ablation for refractive surgery should use individual Q-value.更多还原