前弹力层下准分子激光原位角膜磨镶术后早期视觉质量的评估

Evaluation of quality of vision in early stage after sub-bowman keratomileusis

目的评估前弹力层下准分子激光原位角膜磨镶术（SBK）治疗中高度近视眼术后早期的视觉质量。方法回顾性系列病例研究。收集2011年5月至11月于重庆明达眼科门诊接受SBK手术的中高度近视眼患者35例（68只眼），对比术前及术后2周、1个月、3个月的视力、角膜前表面及全眼像差、明光和眩光对比敏感度的变化情况。对数据进行描述性统计、重复测量方差分析、协方差分析等。全眼波阵面的数据采用波阵面直径作为协变量的方差分析。对比敏感度数据经对数转换后进行统计分析。结果SBK术前裸眼视力（UCVA）和最佳矫正视力（BCVA）的中位数分别为0．05、1．00。术后2周、1个月、3个月UCVA中位数均为1．20。角膜前表面总像差术后与术前比较差异均无统计学意义（F=0．712，P〉0．05），但术后2周总高阶像差为（1．37±0．72）μm，约增为术前的3倍。全眼总像差术后2周为（0．99±0．58）μm，约减少为术前的1／8，总高阶像差术后2周为（0．46±0．19）μm约为术前的1．5倍。明光和眩光对比敏感度在SBK术后有一定的波动，但与术前相比均没有出现有统计学意义的降低，术后3个月时眩光对比敏感度反而在高空间频率（12和18c／d）较术前分别增加0．294（F=20．88，P〈0．01）和0．296（F=13．64，P〈0．01）。结论中高度近视眼患者在SBK术后早期可获得良好的视觉质量。

Objective To assess the quality of vision in the early stage after sub-bowman keratomileusis （SBK） for the correction of moderate and high myopia. Methods Retrospective case series. Sixty eight myopic eyes of 35 consecutive patients in Chongqing Medal Eye Institute from May to November 2011 were enrolled in this study. All patients were evaluated at 2 weeks, 1and 3 months postoperatively. The main measurements included visual acuity, corneal and total optical wavefront aberration, photopic and mesopic contrast sensitivity. Results The median values of preoperative uncorrected central visual acuity （UCVA） and best corrected visual acuity （BCVA） were 0. 05 and 1.00, respectively. The median value of postoperative UCVA was 1.20. There was no significant difference between the preoperative and postoperative anterior corneal total aberration （ F = 0. 712, P 〉 0. 05 ）. Compared with preoperative value （0. 47 ±0. 17） μm, the corneal high orders aberrations in 2 weeks after SBK （ 1.37 ±0. 72）μm increased by 3 times. The total optical aberrations in 2 weeks after SBK （0. 99 ± 0. 58 ） μm decreased to one-eighth of preoperative measurements （8.26 ± 2. 93 ） μm . Compared with preoperative value （0. 30 ± 0. 12 ） μm, the total high order aberrations in 2 weeks after SBK （0. 46 ± 0. 19） μm increased by 1.5 times. Although photopic and mesopic contrast sensitivity fluctuated mildly after SBK, the measurements did not decline significantly. Compared with preoperative data, mesopic contrast sensitivity at 3 months increased 0. 294 （F=20.88,P〈0.01） and 0.296 （F= 13.64,P〈0.01） at 12 and 18 c/d, respectively. Conclusion Patients could obtain could quality of vision at the early stage after SBK.