飞秒激光制瓣与板层角膜刀制瓣LASIK术后视觉质量及眼内散射

Objective optical quality and intraocular scatter after LASIK： femtosecond laser versus mechanical microkeratome

目的 探讨飞秒激光制瓣及板层角膜刀制瓣准分子激光原位角膜磨镶术后客观视觉质量及眼内散射.方法 回顾性研究.符合常规手术适应证,术前矫正视力≥5.0的近视患者72例（72眼）.飞秒激光制瓣LASIK组（F-LASIK）35例（35眼）,术前屈光度（-6.18±2.25）D;角膜刀制瓣LASIK组（M-LASIK）37例（37眼）,术前屈光度（-6.62±1.78）D.术后1年应用客观视觉质量分析系统测量以下指标：调制传递函数截止频率（MTFcutoff）,斯特列尔比以及眼内散射指数.2组间各参数比较应用独立极样t检验或Wilcoxon秩和检验.结果 2组术后均无最佳矫正视力丢失.安全指数F-LASIK组为1.06±0.12,M-LASIK组为1.05±0.14,2组差异无统计学意义（t=0.382,P＞0.05）;有效指数F-LASIK组为1.04±0.15,M-LASIK组为1.04±0.14,2组差异无统计学意义（t=0.156,P＞0.05）.F-LASIK组术后调制传递函数截止频率和斯特列尔比分别为（33.44±6.77） c/d和0.18±0.01,显著高于M-LASIK组[（29.14±9.08）c/d（t=2.264,P＜0.05）和0.16±0.01（t=2.439,P＜0.05）].F-LASIK组术后眼内散射指数为0.77±0.39,M-LASIK组为1.07±0.63,2组间差异无统计学意义（Z=-1.809,P＞0.05）.结论 F-LASIK术后可获得较好的客观视觉质量,调制传递函数截止频率和眼内散射的相关因素有待进一步探讨.

Objective To investigate the objective optical quality and intraocular scatter after femtosecond laser and mechanical microkeratome LASIK for myopia correction.Methods This was a retrospective study.Seventy-two myopic eyes of 72 patients who conformed to the criteria for LASIK in preoperative examinations were enrolled.Patients had a best corrected visual acuity （BCVA） of ≥ 1.0.Thirty-five eyes of 35 patients were treated with LASIK with femtosecond laser flap preparation （F-LASIK）,male∶female ratio=1∶1.3; 37 eyes of 37 patients were enrolled in the control group with microkeratome flap preparation （M-LASIK）,male∶female ratio=l∶2.7.Optical quality parameters were measured in each patient 1 year after the LASIK surgeries：modulation transfer function cutoff frequency （MTFcutoff,cycles per degree,c/d）,Strehl2D ratio （SR） and objective scatter index （OSI）.Results Mean age was 26.71±5.89 years in the F-LASIK group and 28.67±6.62 years in the M-LASIK group;mean spherical equivalent refraction （SE） was-6.18±2.25 D in the F-LASIK group and-6.62±1.78 D in the M-LASIK group.Neither group had a reduction in BCVA.The safety index was 1.06±0.12 in the F-LASIK group and 1.05±0.14 in the M-LASIK group （t=0.382,P〉0.05）,while the efficacy index was 1.04±0.15 in the F-LASIK group and 1.04±0.14 in the M-LASIK group （t=0.156,P〉 0.05）.Mean postoperative MTFcutoff was 33.44±6.77 c/d after F-LASIK,which was significantly greater than the mean value of 29.14±9.08 c/d in the M-LASIK （t=2.264,P〈0.05）; mean SR was 0.18±0.01 in the F-LASIK,which was significantly greater than the mean value of 0.16±0.01 in the M-LASIK （t=2.439,P〈0.05）.Mean OSI was similar between the two groups,with 0.77±0.39 in the F-LASIK group and 1.07±0.63 in the the M-LASIK group （Z=-1.809,P〉0.05）.Conclusion Patients acquire better objective optical quality after femtosecond laser LASIK.However,further study is needed to investigate the factors associated with MTFcutoff and intraocular scatter.