使用六维眼球跟踪系统的飞秒激光辅助前弹力层下角膜磨镶术矫正近视和散光的疗效分析

Analysis of the efficacy of femtosecond laser-assisted sub-Bowman keratomileusis on the correction of myopia and astigmatism with six dimensional eye tracking system

目的评价飞秒激光辅助前弹力层下角膜磨镶术(femtosecond laser-assisted sub-Bowman keratomileusis,FS-SBK)中使用六维眼球跟踪系统矫正近视及散光的有效性。方法回顾性分析2016年3月—11月行FS-SBK的屈光不正患者23例(36只眼),根据术中是否行静态眼球自旋跟踪功能(static cyclotorsion control,SCC)分为2组,其中SCC组11例(20只眼),非SCC组12例(16只眼); SCC组内再根据术中静态眼球旋转度数分为±2°以内组(5例9只眼)、±2~±5°组(4例7只眼)、±5°以上组(2例4只眼)3组。分别采集患者术前、术后1个月的裸眼视力、最佳矫正视力、球镜度数、柱镜度数、角膜曲率和术中SCC度数,提取瞳孔直径为6.5 mm时的总高阶像差、球差、彗差、斯特尔比率等的均方根值,并观察治疗的有效性。结果所有研究对象未出现术中及术后的严重并发症。SCC组与非SCC组有效性指数差异无统计学意义(0.947±0.145、1.005±0.141,P>0.05)。两组患者术后术眼的裸眼视力均较术前明显提高,球镜度数、柱镜度数、角膜曲率差值较术前降低,总高阶像差、球差、彗差较术前增加,差异均有统计学意义(P<0.05)。在SCC组内,术后斯特尔比率与术前的差异有统计学意义(P<0.05)。术后各指标两组间差异均无统计学意义(P>0.05)。术前术后彗差的差值在SCC组与非SCC组差异有统计学意义(P<0.05)。在SCC组内不同眼球旋转度数组间,各指标术前术后差值的差异均无统计学意义(P>0.05)。结论使用六维眼球跟踪系统的FS-SBK矫正近视及散光有效。FS-SBK在减少低阶像差的同时会引入高阶像差,术中是否行SCC对此无明显影响。

ObjectiveTo evaluate the effectiveness of using a six-dimensional eye-tracking system during femtosecond laser-assisted sub-Bowman keratomileusis （FS-SBK） surgery to correct myopia and astigmatism. MethodsA total of 23 patients （36 eyes） with ametropia undergoing FS-SBK were retrospectively analyzed and divided into the static cyclotorsion control （SCC） group （11 patients, 20 eyes） and the non-SCC group （12 patients, 16 eyes）. According to the static eyeball rotation degrees, the SCC group was further divided into three subgroups： within ±2° group （5 patients, 9 eyes）, ±2°-±5° group （4 patients, 7 eyes）, and above ±5° group （2 patients, 4 eyes）. The preoprative and postoperative one-month uncorrected visual acuity, best corrected visual acuity, diopter of spherical power, diopter of cylindrical power, corneal curvature, and the rotating degree in SCC were observed; the root-mean-square values of the total higher-order aberrations, spherical aberration, coma, Strehl ratio, etc. when the pupil diameter was 6.5 mm were extracted; and the therapeutic efficacy was observed. ResultsNo severe intraoperative or postoperative complications occurred in any subject. The effectiveness index of the SCC group was 0.947±0.145, and that of the non-SCC group was 1.005±0.141, with no statistically significant difference （P〉0.05）. Compared with the preoperative levels, in the two groups, the postoperative uncorrected visual acuity was significantly elevated; the postoperative diopter of spherical power, diopter of cylindrical power, and corneal curvature difference were reduced; the postoperative total higher-order aberrations, spherical aberration, and coma increased; all the differences mentioned above were statistically significant （P〈0.05）. In the SCC group, the difference between the preoperative and the postoperative Strehl ratio was statistically significant （P〈0.05）. There was no significant difference in postoperative indicators between the SCC group and the non-SCC group （P〉0.05）. The difference in postoperative increment of coma between the SCC group and the non-SCC group was statistically significant （P〈0.05）. In the SCC group, no statistically significant difference was found in postoperative increment of any indicator among the three subgroups （P〈0.05）. ConclusionsFS-SBK of six-dimensional eye-tracking system is effective in correcting myopia and astigmatism. FS-SBK can reduce lower-order aberrations while introducing higher-order aberrations, and whether SCC is performed intraoperatively is meaningless.