机械刀完成的薄瓣LASIK改善RK术后视觉质量的临床分析

Observation of mechanical automated microkeratome LASIK treat poor visual quality after radial keratotomy

目的探讨机械刀完成的薄瓣准分子激光原位角膜磨镶术（LASIK）矫正放射状角膜切开术（RK）后屈光不正的安全性、有效性与可预测性。方法回顾性系列病例研究。RK近视矫正术后视功能下降要求再次手术矫正的病例27例（38眼），近视20眼，远视18眼，其中22眼合并不规则散光。RK术后11-24年，年龄38-53岁，等效球镜度-9．50-＋4．25D，放射状角膜切口8-32条，角膜厚度512~557Ixm。应用OUP-SBK角膜板层刀制作角膜瓣，采用Allegretto准分子激光治疗系统进行基质切削。合并不规则散光病例应用角膜地形图引导的个性化切削，其他的采用优化模式进行切削。数据采用配对t检验和单因素方差分析进行比较。结果术中未发生角膜瓣游离、纽扣瓣、不全瓣以及角膜瓣碎裂，未发生眼球破裂。角膜瓣厚度（102．0±7．7）μm。角膜基质平滑，9眼角膜上皮边缘缺损，7眼角膜边缘出血。术后第1天角膜瓣透明，上皮完整，术后1d、1周、1个月、6个月裸眼视力大于或等于术前最佳矫正视力（BCVA）的比例分别为63％、82％、88％、87％。38眼术后的BCVA均大于或等于术前BCVA。进行角膜地形图引导的个体化切削的22眼，术后治疗区偏移及治疗光学区过小等情况得到了不同程度的矫正，手术前后彗差、总高阶像差明显减小（t=-3．70、4．10，P〈0．01），3．0c／d及18．0e／d频率上的对比敏感度差异有统计学意义（t=-2．45、-3．24，P〈0．01）。结论放射状角膜切开术后出现的视功能下降采用机械刀薄瓣LASIK再次手术矫正安全、有效，同时可明显地改善部分患者的视觉质量。

Objective To evaluate the safety, efficacy, and predictability of mechanical automated microkeratome laser in situ keratomileusis （LASIK） in eyes underwent radial keratotomy （RK）. Methods In this retrospective case-series study, 38 eyes of 27 patients who had undergone RK were performed automated microkeratome One Use-Plus LASIK, including 20 myopic eyes and 18 hyperopic eyes, among them 22 eyes with irregular astigmatism. The patients were 11-24 years after RK, 38-53 years old, The mean spherical equivalent was -9.50-＋4.25 D, the number of RK incisions was 8-32, the cornea thickness was 512-557 μm. An Allegretto system was used. Datawere analyzed using a paired samples t test and a one-way ANOVA. Results No free flap, incomplete flap and flap or eye ball broken happened during the surgeries. The flap thickness was （102.0±7.7）μm. The stromal bed was smooth, 9 eyes with corneal epithelial border defect was found and 7 eyes with cornea bleeding. The percentage of uncorrected visual acuity equal to or better thanpreoperative best corrected visual acuity （BCVA） at 1 day, 1 week, 1 month and 6 months after surgery was 63%, 82%, 88% and 87%. Postoperative BCVA post surgery of all the 38 eyes were equal to or better than BCVA before surgery. Excursion or undersize of the operation field in 22 eyes which received corneal topography guided individual surgery was corrected in varying degree. Thecoma, total higher-order aberration were reduced obviously after surgery （t= The significant difference of contrast sensitivity was found in the frequency of （t=-2.45, -3.24, P〈0.01）. Conclusion Automated microkeratome One Use-Plus and safe method to treat post-RK poor visual outcomes. 3.70, 4.10, P〈0.01）. 3.0 c/d and 18.0 c/d LASIK is an effective