准分子激光原位角膜磨镶术后散光增大的变化及处理时机

目的 探讨准分子激光原位角膜磨镶术（LASIK）后散光增大的变化及处理时机.方法 选择2009年7月～2013年7月乐清市第三人民医接LASIK术后散光值增大的近视患者20例（38眼）为研究对象,检测并比较患者LASIK手术前后裸眼视力、最佳矫正视力、角膜后散光度、角膜前散光度以及术后1、3、6个月平均散光状况.结果 ①LASIK手术前后等效球镜（-6.13±2.92）D比（0.44±0.34）D]、散光值（0.94±0.42）D比（0.23±0.17）D]、角膜中央厚度（533.29±27.19）mm比（455.08±22.39）mm]及角膜后表面平均屈光力（-6.53±0.32）D比（-6.95±0.38）D]比较,差异均有高度统计学意义（P＜ 0.01）.②LASIK术后角膜后表面3mm区散光值（0.53±0.19）D]高于术前（0.42±0.17）D],差异有统计学意义（P＜0.05）;手术前后5 mm区散光值相比,差异无统计学意义（P＞0.05）.③LASIK术后角膜前表面3 mm区散光度（1.18±0.55）D]及5mm区散光度（1.23±0.71）D]均低于术前（1.58±0.62）、（1.54±0.52）D],差异均有高度统计学意义（P＜0.01）.④后1、3、6个月全眼散光度及角膜散光度与术前比较,均显著增加,差异有高度统计学意义（P＜0.01）;术后1、3、6个月全眼轴向及角膜轴向与术前比较,差异无统计学意义（P＞0.05）.结论 LASIK术后出现散光度增大的主要原因在于角膜基质床泪液分泌过多以及角膜瓣发生水肿,术后6个月内角膜散光度及轴位未发生明显变化,是处理的最佳时机.

Change of astigmatism after laser in situ keratomileusis and the opportunity of management

Objective To analyze the change of astigmatism after laser in situ keratomileusis （LASIK） and the opportunity of management.Methods 20 cases of shortsightedness with postoperative astigmatism enlargement （38 eyes） from July 2009 to July 2013 in the Third People＇s Hospital of Yueqing City after the LASIK operation were selected.The visual acuity,best corrected visual acuity,corneal astigmatism,corneal astigmatism and average astigmatism 1,3,6 months after the operation were measured and compared.Results ①The differences of spherical equivalent （-6.13±2.92） D vs （0.44±0.34） D],astigmatism value （0.94±0.42） D vs （0.23±0.17） D],central corneal thickness （533.29±27.19） mm vs （455.08±22.39） mm],average refractive power after corneal surface （-6.53±0.32） D vs （-6.95±0.38） D]before and after the LASIK operation were statistically significant （P ＜ 0.01）.②Astigmatism value of 3 mm corneal posterior surface after the LASIK operation （0.53±0.19） D] was higher than that before the LASIK operation,the difference was statistically significant （P ＜ 0.05）; the difference of astigmatism value of 5 mm corneal posterior surface before and after the LASIK operation was not statistically significant （P ＞ 0.05）.③The difference of astigmatism value of 3 mm and 5 mm corneal anterior surface after the LASIK operation （1.18±0.55）,（1.23±0.71） D] were all lower than those before the LASIK operation,the differences were statistically significant （P ＜ 0.01）.④The whole eye astigmatism value and corneal astigmatism value 1,3,6 months after the LASIK operation were all higher than those before the operation,the differences were statistically significant （P ＜ 0.01）; the difference of whole eye axis,astigmatism axis before and 1,3,6 months after the LASIK operation was not statistically significant （P ＞ 0.05）.Conclusion The primary cause of postoperative astigmatism enlargement are corneal stroma bed tear hypersecretion and corneal flap edema.There are no significant changes in astigmatism and axis within 6 months after surgery,which is the best time to treat.