摘要目的 研究Nd:YAG激光后囊膜切开术对后发性白内障患者光学像差的影响,客观评价视觉质量.方法 采用回顾性对照研究.对选择Ⅱ级膜(后囊膜中度混浊,眼底部分模糊不清)20例(25只眼)明显影响视力的后发性白内障患者行Nd:YAG激光后囊膜切开手术,术中选用不同激光脉冲及能量.手术前后采用裂隙灯数码照相机进行眼底红反光照像,激光术后用Adobe photoshop7.0软件联合MB-ruler测量截囊口的大小.使用i-Trace波前像差仪进行术前后视觉质量的分析,测量4 mm瞳孔波前像差及空间频率为5～30 (c/pd)调制传递函数(MTF)值的改变.记录患者激光术前后患者在自然瞳孔下最佳矫正视力.结果 Nd:YAG激光后囊膜截开术后最佳矫正视力均明显提高,由平均LogMAR视力0.62改变为0.20;术前总高阶像差均方根值0.589 (SD0.108),其中三叶草像差占高阶像差的主要部分为0.315 (SD0.094).激光手术1月后总、高阶像差及各阶像差对应的均方根值较术前明显减小(P＜0.05).5～30 c/d空间频率下MTF值激光后囊膜切开术前后比较差异有统计学差异,MTF值均有明显提高(P＜0.05).结论 Nd:YAG激光后囊膜切开术治疗后发性白内障患者,术后最佳矫正视力明显提高,同时与术前比较光学波前像差降低,术后可以重新获得较好视觉质量.

abstractsObjective To evaluate the effect of Nd:YAG laser posterior capsulotomy on ocular wave-front aberrations and assess the vision quality objectively.Methods A prospective comparative study.Twenty-five eyes of 20 consecutive pseudophakic patients with symptomatic PCO,which impaired the visual acuity severely,who presented for Nd:YAG laser posterior capsulotomy at our clinic,were included in this study.According to the different type,different laser parameter was chosen.Before and after Nd:YAG laser posterior capsulotomy,using slit-lamp digital camera and then the Adobe photograph7.0 software combined with MB-ruler to calculate the diameter of the opening size.The wave-front aberrations of the entire optical path of 25 pseudophakic eyes of 20 patients before,and 1 month after,Nd:YAG laser posterior capsulotomy were measured using i-Trace visual function analyzer.Total,high-order aberrations,and total coma,trefoil,spherical aberrations were analyzed statistically.The changes in best corrected visual acuity were also measured.Results Significant improvement in visual acuity was observed after Nd:YAG laser posterior capsulotomy,mean logMAR visual acuity 0.62 to 0.20.Before the procedure,the total higher-order aberrations root mean-square (RMS) wave front aberration was 0.589 (SD 0.108)μm,with trefoil being a major contributor at 0.315 (SD 0.094)μm.One month after the procedure,significant decreases in total,high-order aberrations,and total coma,trefoil,spherical aberrations were noted (P ＜0.05).Additionally,MTF (t-HOA) values at 5-30cpd got significantly improvement after Nd:YAG laser posterior capsulotomy (P ＜0.05).Conclusions Nd:YAG laser posterior capsulotomy,best corrected visual acuity is improved and caused significant decrease in ocular wave-front aberrations measured using i-Trace visual function analyzer,which can account for a better optical quality after the procedure.