目的：探讨不同引导方式LASIK术后角膜非球面性改变及临床分析。 方法：48例95眼行LASIK手术，其中45眼接受Q值引导LASIK，50眼接受非Q值引导的LASIK。术后1,3,6mo分别检查视力（visual acuity,VA）、屈光状态、角膜K值、Q值、球差、对比敏感度(contrast sensitivity function, CSF)等，并行统计分析。 结果：两组术后3，6mo在视力和有效指数方面无差异；术后3mo屈光状态在±0.50D范围Q值组和非Q值组分别为95%和90%，术后6mo，±0.50D两组分别为97%和98%；术后1,3和6mo Q值组CSF均较术前提高，差异有统计学意义（P<0.05），而非Q值组术前术后差异无统计学意义。Q值组和非Q值组术后1,3和6mo的平均Q值分别为0.50±0.33和0.81±0.51、0.50±0.35和0.80±0.48、0.50±0.34和0.80±0.47，与术前比较差异均有统计学意义。Q值组和非Q值组术后6mo球差较术前平均增加分别为4倍和8.5倍；⊿Q与预矫屈光度高度正相关，与患者年龄、性别、术前角膜K值、Q值、球差无相关性；定量关系非Q值组为y= 0.18e^0.32x ，R²=0.72，Q值组为y=0.04x²-0.19x+0.54，R²=0.75。 结论：非球面引导的LASIK可以有效地减少近视屈光手术对角膜非球面性的影响，从而减少术后球差的增加，有利于术后视觉质量的提高。预计的目标Q值与实际的Q值之间存在较大差异。"

To investigate the effects of different laser in situ keratomileusis(LASIK) ablations on clinical outcomes and corneal asphericity. METHODS: Totally 48 cases (95 eyes) were treated by LASIK, with 45 eyes using Q-value guided ablation (aspherical ablation), and 50 eyes using non-Q-value guided ablation. Visual acuity (VA), refraction, keratometry, Q-value, spherical aberration and contrast sensitivity function (CSF) were assessed at 1, 3 and 6 months after operation. RESULTS: There were no statistically significant differences in VA and refraction between the two groups after surgery. The rate of refraction within 0.50D was 95% for Q-value group and 90% for non-Q-value group at postoperative 3 months, with 97% and 98% at 6 months. The postoperative CSF was elevated in Q-value group, whereas no difference between preoperation and postoperation in non-Q-value group. The average Q-value was about -0.18 for both groups before the surgery, and after the surgery it was about 0.50 for Q group and 0.80 for non-Q group. The postoperative 6 months spherical aberration increased to 4 times in Q-value group and 8.5 times in non-Q-value group compared to preoperation. There was a tight relation between ⊿Q and attempted refraction, without relation between ⊿Q and age, gender, preoperative keratometry, Q-value and spherical aberration. The formula obtained through curve fitting was y=0.18e^0.32x，R² = 0.72，for non-Q-value group, and y= 0.04x²-0.19x+0.54，R²= 0.75, for Q-value group(y:⊿Q, x: attempted refraction). CONCLUSION: Compared to non-Q-value guided ablation, Q-value guided ablation of LASIK for treating myopia can reduce destroy on corneal asphericity, causing less increment in spherical aberration and improving visual quality after the surgery. But it still had a distance between the expected and the actual postoperative Q-values. The postoperative increment of Q-value was tightly related with attempted refraction."