Huang David, Arif Muhammad
Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
J Cataract Refract Surg. 2002 Mar;28(3):407-16. doi: 10.1016/s0886-3350(01)01163-4.
To investigate the effect of laser spot size on the outcome of aberration correction with scanning laser corneal ablation.
Cleveland Clinic Foundation, Cleveland, Ohio, USA.
Corrections of wavefront aberrations of Zernike modes from the second to eighth order were simulated. Gaussian and top-hat beams of 0.6 to 2.0 mm full-width-half-maximum diameters were modeled. The fractional correction and secondary aberration (distortion) were evaluated.
Using a distortion/correction ratio of less than 0.5 as a cutoff for adequate performance, a 2.0 mm or smaller beam was adequate for spherocylindrical correction (Zernike second order), a 1.0 mm or smaller beam was adequate for correction of up to fourth-order Zernike modes, and a 0.6 mm or smaller beam was adequate for correction of up to sixth-order Zernike modes.
Since ocular aberrations above the Zernike fourth order are relatively insignificant in normal eyes, current scanning lasers with a beam diameter of 1.0 mm or less are theoretically capable of eliminating most higher-order aberrations.
研究激光光斑大小对扫描激光角膜消融术矫正像差效果的影响。
美国俄亥俄州克利夫兰市克利夫兰诊所基金会。
模拟了对从二阶到八阶泽尼克模式的波前像差进行矫正。对半高全宽直径为0.6至2.0毫米的高斯光束和平顶光束进行了建模。评估了分数矫正和二级像差（畸变）。
使用小于0.5的畸变/矫正比作为足够性能的截止值，2.0毫米或更小的光束足以进行球柱面矫正（泽尼克二阶），1.0毫米或更小的光束足以矫正高达四阶的泽尼克模式，0.6毫米或更小的光束足以矫正高达六阶的泽尼克模式。
由于在正常眼睛中泽尼克四阶以上的眼像差相对不显著，目前光束直径为1.0毫米或更小的扫描激光理论上能够消除大多数高阶像差。
