影响近视眼患者近视屈光度的相关因素分析

Analysis of correlative factors effecting on diopter in myopia

目的了解近视眼患者近视屈光度、眼轴长度、角膜曲率及角膜厚度的相关关系,以探讨各因素对近视屈光度的影响。设计前瞻性病例系列。研究对象近视患者300例,每例对一眼进行研究。方法随机抽取欲行LASIK手术治疗的近视患者300例,按近视程度分为四组,低度近视(≤-3．00D)41例,中度近视(＞-3．00,≤-6．00D)130例,高度近视(＞-6．00,≤-9．00D)95例,超高度近视(＞-9．00D)34例。经散瞳检影验光、OrbscanⅡ角膜地形图系统及A超检测患者LASIK术前近视度数、角膜曲率、眼轴长度及角膜中央厚度,统计每例患者一只眼的数据(共300眼),对各组数据进行方差分析、Pearson相关分析和多元线性回归分析。主要指标近视度数、角膜曲率、眼轴长度及角膜中央厚度。结果低度、中度、高度、超高度近视组眼轴长度分别为(24．32±1．73)mm．(25．33±1．49)mm,(26．04±1．92)mm,(27．47±2．57)mm,各近视组之间比较差异具有统计学意义(P=0．000),角膜曲率仅在高度近视组分别与低、中度近视组之间存在显著性差异,各组角膜厚度之间比较差异无统计学意义(P=0．409)。眼轴长度分别与近视屈光度(r=0．734,P=0．000)及垂直、水平径角膜曲率(r=-0．312,P=-0．000；r=-0．328,P=0．000)相关。结论对于低、中、超高度近视眼患者,眼轴增长为影响近视屈光度的主要因素,高度近视患者还同时受角膜曲率改变的影响。随着眼轴的变长近视屈光度增高,角膜曲率变小,角膜变平。不同量的角膜曲率改变和不同量的眼轴增长互相配合,可以形成不同程度的近视。(眼科,2006,15：321-323)

Objective To study the correlations between diopter, axis length, cornea curvature and thickness in myopia patients. Design Prospective case series. Participant 300 myopic patients who were ready for LASIK. Method 300 myopic patients who were ready for LASIK were selected randomly. They were divided into four groups according to the diopter of myopia： low myopia group （≤-3.00D） 41 cases, medium myopia group （〉-3.00D, ≤-6.00D）130 cases, high myopia group （〉-6.00D,≤-9.00D） 95 cases, and super myopia group （〉-9.00D）34 cases. The axis length, cornea thickness, cornea curvture and diopter of myopia were detected. Through analysis of variance （ANOVA）, Pearson correlation analysis and linear regression analysis, the correlations between axis length, cornea thickness, curvature and diopter of myopia were made out in four groups. Main Outcome Measure Diopter of myopia, cornea curvature, axis length of eye and central cornea thickness. Result The axis length of low myopia group, medium myopia group, high myopia group and super myopia group was （24.32±1.73）mm, （25.33±1.49）mm, （26.04±1.92）mm, （27.47±2.57）mm respectively. There were obvious differences of axis lengths between four groups （P=0.000）. The cornea curvature in high myopia group was obviously different from those in low myopia group and medium myopia group. There were no significant differences of cornea thickness among four groups （P=0.409） . The axis lengths of eyes respectively had correlations with diopters （r=0.734,P=0.000）, vertical and horizontal cornea curvatures （r=-0.312,P=0.000;r=-0.328,P=0.000）. Conclusion The main effective factor on the diopter of myopia is the axis length for most patients. For the patients with high myopia, the cornea curvature is another effective factor. With the increase of axis length, the cornea curvature decreases, and the cornea turns flatter.