青年近视眼角膜前表面高阶像差的研究

Study on higher order aberrations of corneal anterior surface in young adult myopia

目的研究青年人近视眼角膜前表面高阶像差与角膜前表面曲率及散光的相关性,探讨角膜高阶像差的影响因素及变化规律。方法采用前瞻性研究,选取符合纳入条件的127例(162眼)为研究对象,按角膜曲率>43 D或≤43 D分为A组和B组,其中A组66例85眼,为高角膜曲率组;B组61例77眼,为低角膜曲率组。而按有无角膜散光又将入选患眼分为Ⅰ组和Ⅱ组,其中Ⅰ组67例94眼,为角膜散光组;Ⅱ组60例68眼,为无角膜散光组。再细分为4个亚组:AⅠ高角膜曲率散光组、AⅡ高角膜曲率无散光组和BⅠ低角膜曲率散光组、BⅡ低角膜曲率无散光组。应用Allegro Oculyzer眼前节分析段系统检测角膜前表面高阶像差,采用独立样本t检验比较各组角膜前表面垂直彗差(Z3-1)、水平彗差(Z3+1)、垂直与水平彗差之和(Z3±1)及球差(Z40)的均方根值,采用Pearson相关分析检测各高阶像差与角膜曲率和散光的相关关系。结果 A组年龄(22±3)岁,角膜曲率(44.53±0.95)D,屈光度等效球镜度数为(5.02±2.23)D;B组年龄(21±3)岁,角膜曲率(41.42±1.04)D,屈光度等效球镜度数为(5.10±2.26)D;Ⅰ组年龄(21±3)岁,角膜曲率(43.21±1.96)D,角膜散光绝对值(1.85±0.69)D,屈光度等效球镜度数为(5.16±2.28)D;Ⅱ组年龄(22±3)岁,角膜曲率(42.98±1.87)D,屈光度等效球镜度数为(4.93±2.20)D。经统计学处理,曲率相关分组中,A组与B组、AⅠ组与BⅠ组、AⅡ组与BⅡ组Z40比较差异均有统计学意义(均为P=0.000),AⅡ组与BⅡ组的Z3-1及Z3±1分别比较差异具有统计学意义(P=0.002、0.017)。散光相关分组中,Ⅰ组与Ⅱ组、BⅠ组与BⅡ组的Z3-1及Z3±1分别比较差异均具有统计学意义(均为P<0.05),而Z40比较差异均无统计学意义(均为P>0.05)。角膜曲率与Z40呈显著正相关(r=0.632,P=0.000),无论是在Ⅰ组还是在Ⅱ组中均呈现这样的显著相关性(分别为r=0.597、P=0.000;r=0.701、P=0.000)。角膜散光与彗差的相关性均无统计学意义(均为P>0.05)。结论角膜前表面曲率与球差存在着明显正相关关系,散光对彗差也有一定影响。这提示我们在进行屈光性手术或治疗中,角膜曲率较大的患眼,因其球差相对较高,更适合非球面技术的运用。

Objective To analyze the correlation of high order aberrations of the corneal anterior surface with its curvature and astigmatism, and explore the effect factors and change rules of these aberrations in young adult myopia. Methods A total of 127 subjects（ 162 eyes）were selected in the trial. Based on the eyes with corneal curvature higher or lower than 43 D,the subjects were divided into group A（66 subjects,85 eyes） and group B （61 subjects, 77 eyes）. Meanwhile, based on the eyes with or without corneal astigmatism,the subjects were divided into group [ （67 subjects,94 eyes, with astigmatism） and group Ⅱ （60 subjects ,58 eyes, without astigmatism）. And then the subjects were subdivided into subgroups of group A Ⅰ , group A Ⅱ, group B Ⅰ and group B Ⅱ, Higher order aberrations were detected by Allegro Oculyzer corneal anterior segment diagnosis system, the independent samples t test and Pearson correlation analysis were used to compare the vertical coma （Z3 -1）, horizontal coma（ Z3 ＋1）, vertical and horizontal coma（Z3 ±1）and spherical aberration （Z4^0）. Results Mean age in group A and B were（22 ±3）years old and（21 ± 3 ）years old, the average corneal curvature were （44.53 ± 0.95 ） D and （41.42 ± 1.04 ） D, the average diopter were （ 5.02 ± 2.23 ） D and （5. 10 ±2.26）D,respectively. Mean age in group Ⅰ and Ⅱ were（21 ±3 ）years old and （22 ±3 ）years old, the average corneal curvature were （43.21 ±1.95 ）D and（42.98 ±1.87 ） D, the average diopter were （5.16 ±2.28 ） D and （4.93 ±2.20 ） D, respectively. The average corneal astigmatism in group [ was （ 1. 85 ±0. 59 ） D. There were significant differences in Z4^0 between group A and B, group A Ⅰ and B Ⅰ , group A Ⅱ and B Ⅱ （ all P = 0.000）, as well as in Z3 - 1 and Z3 ±1 between group A Ⅱ and B Ⅱ （P = 0. 002,0. 017 ）. Significant differences were also found in Z3 - 1 and Z3 ±1 between group Ⅰ and Ⅱ, group B Ⅰ and B Ⅱ （all P = 0. 000）, and there was no significant difference in Z4^0（ all P 〉 0.05 ）. The corneal curvature was positively correlated with spherical aberration （Z4^0） （r = 0. 632 ,P = 0. 000 ）, whether with or without corneal astigmatism （ r = 0. 597,0. 701, P = 0. 000,0. 000） ;While the correlations between corneal astigmatism and coma aberrations was no statistically significant （ all P 〉 0.05 ）. Conelusion The corneal curvature is positive correlated with corneal spherical aberration, and the corneal astigmatism has effects on corneal coma, which indicate that it is more suitable for eyes with higher corneal curvature to use non-spherical technology on refractive operations or treatments.