波前像差引导的LASIK手术的临床效果观察

Clinical results of wavefront-guided laser in situ keratomileusis 3 months after surgery

目的 :观察波前像差引导的LASIK手术矫正近视性散光的效果。方法 :2 8例 35只眼 ,平均术前球镜屈光度为 (- 4.8± 2 .3)D ,柱镜屈光度为 (- 1.1± 0 .9)D。手术前和手术后均使用Tscherning像差计测量 ,分析波前像差。应用 1.0mm光斑、频率 2 0 0Hz的飞点扫描准分子激光进行屈光手术。结果 :术后 3个月 ,6 8.0 %的眼屈光度在± 0 .5D(正视眼 )内 ,93.5 %眼在± 1.0D内。 93.5 %的裸眼视力为 2 0 / 2 0或更好。裸眼超常视力(BSCVA在 2 0 / 10或更好 )占 16 .0 %。高阶像差 (球差 ,彗差 )矫正不足 ,而波前像差全部均方根增加值为 1.44± 0 .74,彗差的矫正好于球差。结论 :波前像差引导的LASIK手术是一种很可靠的技术 ,可有效地矫正屈光不正 ,改善视觉敏感度 ,提高视觉质量 ,尤其是提高夜间视力的视觉质量。

Objective:To investigate the visual and refractive outcome of wavefront guided laser in situ keratomileusis(LASIK) to correct myopic astigmatism.Methods:This prospective study comprised 35 eyes of 28 patients who had a mean preoperative spherical refraction of -4.8 diopters(D)±2.3(SD) and a cylinder of (-1.1±0.9)D. Preoperative and postoperative wavefront analysis was performed with a Tscherning aberrometer. A scanning spot laser with a 1.0mm spot size and a 200Hz repetition rate was used. The eye tracking system had a response time of less than 6 milliseconds. The treatment area diameter ranged from 6.0 to 7.0mm with a transition zone of 1.0mm.Results:At 3 months,68.0% of the eyes were within ±0.5D of emmetropia and 93.5% were within ±1.0D. Uncorrected visual acuity was 20/20 or better in 93.5% of eyes. No eye lost more than 1 line of low contrast,glare,and best spectacle corrected visual acuity(BSCVA). Supernormal vision(BSCVA of 20/10 or better) was achieved in 16.0% of eyes. The correction of higher order aberrations(spherical aberration,coma) was insufficient,with an inverse factor of the overall root mean square wavefront error of 1.44±0.74. Coma was better corrected than spherical aberration.Conclusion:Wavefront guided LASIK is a promising technique that offers the potential to correct refractive errors,to improve visual acuity,and to increase the quality of vision,especially under mesopic conditions. Studies that include selective overcorrection of different Zernike components are needed to achieve better correction of the aberrations. Prospective controlled clinical studies must clarify the major benefits of wavefront guided LASIK.