准分子激光角膜原位磨镶术后远期视觉质量的观察

Evaluation of long-term optical quality after laser in situ keratomileusis for myopia

目的:研究接受准分子激光角膜原位磨镶术(Laser in situ keratomileusis,LASIK)患者的视觉质量在术后数年内是否稳定,应用视觉质量分析系统(Optical Quality Analysis System,OQASⅡ)对LASIK术后远期视觉质量进行评价。方法:从第四军医大学学员中招募志愿者作为受试者,从中选择曾行LASIK手术者35例70眼作为观察组,未行LASIK手术者70例140眼作为对照组,应用OQASⅡ比较近期观察组(LASIK术后2~4a)和远期观察组(LASIK术后5~11a)的视觉质量,通过设立近期对照组(≤22岁)和远期对照组(≥23岁)探讨年龄、用眼习惯等混杂因素对视觉质量的影响,并分别与近期观察组和远期观察组相比较。观察指标为客观散射指数(OSI)、MTF截止空间频率(MTF cutoff)、斯特列尔比值(SR)、100%对比敏感度的OQAS分值(OV100%)、20%对比敏感度的OQAS分值(OV20%)和9%对比敏感度的OQAS分值(OV9%)。结果:在术后数年内,观察组的OSI显著高于对照组,而MTF cutoff、SR以及OV100%、OV20%和OV9%显著低于对照组(P<0.05);随术后时间延长,视觉质量基本保持稳定,OSI有一定降低的趋势,而MTF cutoff、SR、OV100%、OV20%、OV9%有一定升高的趋势,但均没有统计学差异(P>0.05)。结论:LASIK是矫正近视的常用手术方法,随术后时间延长,因手术一定程度降低的视觉质量有恢复的趋势,但在数年内不能完全恢复,基本保持稳定的状态。OQAS能够对LASIK术后的视觉质量进行定性和定量分析,有助于近视矫正术后视觉质量的分析和手术方案的改进。

·AIM：To evaluate the stabilization of long-term optical quality after laser in situ keratomileusis （ LASIK ） for myopia by Optical Quality Analysis System. ·METHODS：Totally 70 eyes from 35 student volunteers after LASIK and 140 eyes from 70 normal student volunteers were recruited from the Fourth Military Medical University. The volunteers after LASIK were divided into recent observation group （ 2 - 4a after LASIK） and long-term observation group （ 5 -10a after LASIK） . The normal volunteers were divided into recent control group and long-term control group, to analysis the influence of confounding factors such as age and eyes-using habit on the optical quality. The observation groups and the control groups were compared respectively. The objective scattering index （ OSI ） , modulation transfer function cutoff frequency （ MTF cutoff）, Strehl ratio （SR）,OQAS value in 100% contrast （ OV100%） , OQAS value in 20% contrast （ OV20%） , OQAS value in 9% contrast （ OV9%） were analyzed. ·RESULTS： The OSI of observation group improved significantly but the MTF cutoff, SR, OV100%, OV20%and OV9% decreased significantly in several years after LASIK （P〈0. 05）. The optical quality is generally stable after LASIK. The OSI had a tendency to reduce and the MTF cutoff, SR, OV100%, OV20% and OV9% had a tendency to improve, but showed no significant difference. ·CONCLUSION： LASIK, one of the most frequent operation methods for myopia correction, can reduce the optical quality in a certain extent. The optical quality has a tendency to recover in several years after LASIK, but not completely. OQAS is a feasible method in assessing the long-term optical quality after LASIK.