Waheed Samra, Chalita Maria Regina, Xu Meng, Krueger Ronald R
Department of Refractive Surgery, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland 44195, Ohio, USA.
J Refract Surg. 2005 Jul-Aug;21(4):346-52. doi: 10.3928/1081-597X-20050701-08.
To identify aberrations created by making a laser in situ keratomileusis (LASIK) flap and treating the refractive error with laser ablation at a later date.
Twenty-two eyes (11 patients) underwent a two-step LASIK procedure with the Alcon LADAR-Vision laser (Alcon Laboratories, Ft Worth, Tex). In the first step, a flap was created, and 1 month later the flap was lifted and laser ablation performed. Aberrations were measured with the LADARWave wavefront measurement device preoperatively, after making the flap (1 day, 1 week, 1 month) and after laser treatment (1 week and 3 months). Two different microkeratomes were used (Moria M2 [Moria; Antony, France] and SKBM [Alcon]). With the SKBM, all flap hinges were nasal; with the Moria M2, the flap hinge was randomly selected as superior in one eye and nasal in the other.
A slight hyperopic shift was seen in the manifest and wavefront refractions at 1 week and 1 month after flap creation for the Moria M2, but not for the SKBM. Statistically significant change in manifest sphere with the Moria M2 showed a mean shift at 1 month of +0.50 +/- 0.08 diopters (D) whereas the SKBM showed no mean shift, but less reproducibility, +0.06 +/- 0.17 D. Higher order aberrations after flap creation were statistically significantly higher for all except coma with both microkeratomes, but with no predictable trends observed. Although higher in magnitude, post flap aberrations were less than one quarter the increase noted in post laser aberrations, except for "other terms."
Creating a LASIK flap induces changes in lower and higher order ocular aberrations. The change in lower order terms is microkeratome dependent. Higher order aberrations increase to a much larger degree after laser than after flap, making a two-step procedure unnecessary in conventional LASIK.
识别制作准分子原位角膜磨镶术（LASIK）瓣并在之后用激光消融治疗屈光不正所产生的像差。
22只眼（11例患者）使用爱尔康LADAR-Vision激光（爱尔康实验室，沃思堡，得克萨斯州）接受了两步LASIK手术。第一步，制作瓣，1个月后掀起瓣并进行激光消融。术前、制作瓣后（1天、1周、1个月）以及激光治疗后（1周和3个月），使用LADARWave波前测量装置测量像差。使用了两种不同的微型角膜刀（Moria M2 [Moria；法国安东尼]和SKBM [爱尔康]）。使用SKBM时，所有瓣蒂均位于鼻侧；使用Moria M2时，一只眼的瓣蒂随机选择为上方，另一只眼的瓣蒂为鼻侧。
对于Moria M2，制作瓣后1周和1个月时，明显验光和波前验光出现轻微远视偏移，但对于SKBM则未出现。使用Moria M2时，明显球镜度的统计学显著变化显示1个月时平均偏移为+0.50±0.08屈光度（D），而SKBM未显示平均偏移，但可重复性较差，为+0.06±0.17 D。制作瓣后，除两种微型角膜刀的彗差外，所有高阶像差在统计学上均显著更高，但未观察到可预测的趋势。尽管幅度更高，但瓣后像差小于激光后像差增加量的四分之一，“其他项”除外。
制作LASIK瓣会引起低阶和高阶眼像差的变化。低阶项的变化取决于微型角膜刀。高阶像差在激光后比瓣后增加的程度大得多，使得传统LASIK中无需两步手术。
