青少年近视眼角膜高阶像差与屈光度关系的相关性

目的〓〖HTK〗了解青少年近视患者角膜高阶像差的分布规律，探讨近视程度对角膜高阶像差的影响。〖HTW〗方法〓〖HTK〗应用Ray Tracing原理设计的iTrace视功能分析仪检测104例104只青少年近视眼，等效球镜为［（-3.98±2.50）D］的角膜像差。在6mm瞳孔直径下测量3～6阶Zernike系数，计算各阶均方根（RMS）值、3～6阶总RMS值、球差（Z04，Z06）及彗差（Z-13，Z13，Z-15，Z15）RMS值，并分别与屈光度进行相关分析。〖HTW〗结果〓〖HTK〗受试者球镜平均为（-3.72±2.36）D，柱镜平均为（-0.77±0.62）D，角膜总高阶像差（3～6阶）的RMS值平均为（0.413±0.134）μm，3阶至6阶的各项Zernike系数大致呈递减趋势（4阶球差Z04除外），所有角膜的Z04（4阶球差）值均为正值，平均（0.272±0.086）μm。近视屈光度大小与角膜总高阶像差、各阶像差的RMS值无相关性，但水平彗差（Z13）与等效球镜呈负相关（P＜0.01）。彗差作为主导像差的频率在高度近视组略增加，而球差是角膜像差中最主要的像差（约占80%），且不随屈光度的变化而变化。〖HTW〗结论〓〖HTK〗在青少年近视中，角膜高阶像差的个体差异较大，仅个别Zernike系数与近视程度有相关性，球差是角膜像差中最主要的像差。

Changes of corneal higher-order wavefront aberrations as a function of the degree of myopia in adolescents

Objective〓〖WTBZ〗To investigate the distribution of corneal high-order aberrations (HOAs, 3rd to 6th orders) myopic eyes of adolescent, and study the changes as a function of the degree of myopia. 〖WTHZ〗Methods〓〖WTBZ〗Using the iTrace Visual Function Analyzer, root mean square(RMS)of total corneal HOAs, 3rd-,4th-,5th-,6th-order aberrations, coma and SA were determined from the central 6.0mm zone of 104 eyes of 104 subjects mean 19.9±1.34 years old, ranging from 16 to 24 years; mean manifest spherical equivalent was (-3.98±2.50)D. Correlation between corneal HOAs and refractive power was analyzed. 〖WTHZ〗Results〓〖WTBZ〗The mean refractive error was sphere (-3.72±2.36)D and cylinder (-0.77±0.62)D, and the mean RMS of corneal total high order(3rd to 6th) was (0.413±0.134)μm. Values of Zernike coefficients progressively decreased from the 3rd-order to the 6th-order (except Z04). The mean coefficient of the 4th-order SAs(Z04) was (0.272±0.086)μm and was positive in all corneas. No correlation was found between total corneal high order RMS and myopia. However, horizonal primary coma(Z13) statistically correlate with spherical equivalent (SE) （P＜0.01）. Coma was more frequent in high myopia as a dominant aberration, and SA occurred equally around 80%. 〖WTHZ〗Conclusions〓〖WTBZ〗Corneal wave front aberrations greatly vary among adolescents, while horizontal primary coma(Z13) slightly decreases with an increase of SE. All corneas have positive 4th-order SAs, and the values are negatively correlated with SE in median myopia. Coma is more frequent in high myopia, and SA is the most influential one in cornea aberrations.