高度近视VisuMax飞秒激光制作超薄角膜瓣预测性研究

目的探讨VisuMax飞秒激光制作超薄角膜瓣应用于高度近视的可预测性及其影响因素。方法前瞻性临床研究。连续选取11例（21眼）欲行飞秒激光原位角膜磨镶术高度近视患者．使用VisuMax飞秒激光制作预计瓣厚度为85μm的超薄角膜瓣，制瓣前、后分别使用A型超声测厚仪测量术眼中央角膜厚度和中央基质床厚度，相减得出实际瓣厚度，采用Pearson相关分析实际角膜瓣厚度与术前眼压、等效球镜度、角膜曲率、水平角膜直径和角膜厚度的相关性。结果平均术中角膜瓣厚度为（96．0±10．5）μm，角膜瓣厚度与术前眼压、等效球镜度、角膜曲率及水平角膜直径的相关性无统计学意义，与术前中央角膜厚度呈正相关（r=0．512，P=0．018）。结论VisuMax飞秒激光制作超薄角膜瓣应用于高度近视的预测性良好，制作85μm瓣的实际瓣厚度与术前中央角膜厚度相关。

Predictability of ultra-thin corneal flap thickness created with VisuMax femtosecond laser in high myopia

Objective To investigate the predictability of ultra-thin corneal flap thickness created with VisuMax femtosecond laser in high myopia and to identify the factors affecting flap thickness. Methods A prospective clinical study involved 21 eyes of 11 high myopia patients who underwent femtosecond laser in situ keratomileusis （LASIK）. The VisuMax femtosecond laser was used to create ultra-thin corneal flaps with an intended central flap thickness of 85 μm. The preoperative central corneal thickness （CCT） and residual stromal bed thickness （RST） after corneal flap lift were measured by ultrasound pachymetry. The actual flap thickness was calculated as thedifference between preoperative CCT and intraoperative RST after flap lift. Pearson correlation analysis was used to compare actual flap thickness and data that included preoperative intraocular pressure, spherical equivalent refractive error （SE）, keratometry, horizontal corneal diameter and preoperative CCT. Results The mean intraoperative corneal flap thickness was （96.0±10.5）μm for all eyes. Corneal flap thickness was not significantly correlated to preoperative SE, intraocular pressure, keratometry or horizontal corneal diameter, but was significantly correlated to preoperative CCT （r=0.512, P=0.018）. Conclusion The thickness of ultra-thin corneal flaps created with VisuMax femtosecond laser in high myopia is essentially predictable. The intended 85 μm corneal flap thickness yields an actual flap thickness that is significantly correlated to preoperative CCT.