角膜屈光手术对眼波前像差的影响

目的　探讨大光斑式切削屈光手术对眼波前像差的影响 ,观察不同瞳孔区眼波前像差的改变。方法　检查 4 5例准分子激光原位角膜磨镶术 (laserinsitukeratomileusis,LASIK)患者术前、术后 10d和术后 1个月的裸眼视力 (uncorrectedvisualacuity ,UCVA)、最佳矫正视力 (bestcorrectedvisualacuity,BCVA)、等效球镜度 (sphericalequivalent,SE)及波前像差 ,根据术前SE将患者分为高度、中度和低度 3个不同的屈光度数组。使用Allegretto客观式波前像差分析仪检查眼部的波前像差 ,将所得数据进行统计学处理。结果　术前平均BCVA为 4 98± 0 0 7;术后 10d平均UCVA为 4 92± 0 10 ,BCVA为 4 95± 0 0 9;术后 1个月时平均UCVA为 4 96± 0 0 9,BCVA为 4 99± 0 0 9。视力在术后随时间延长而好转 ,术后 1个月时 2 6只眼 (30 6 % )BCVA好于术前。术后 10d各组的SE为轻度远视或正视状态 ,随时间延长向近视方向漂移。各屈光度数组内 ,术后 10d与 1个月时 ,高阶像差为术前的 2倍以上 ,以 5阶二次彗差为最 (P <0 0 5 ) ;术后 1个月 ,高阶像差比术后 10d有减小 (P >0 0 5 ) ,但未恢复至术前水平。总像差术后较术前减小。各组内 ,无论术前术后 ,瞳孔直径为 6 5mm时的像差显著大于瞳孔直径为 4mm时的像差 (P <0

Influence of corneal refractive surgery on wavefront aberrations of human eye

OBJECTIVE: To analyze the aberration of human eyes after LASIK by using wavefront analyzer, to evaluate the eye aberrations by using the large spot in refractive surgery, and to compare the aberrations in different pupil zones. METHODS: This is a prospective clinical study. Preoperatively and postoperatively, uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), spherical equivalent (SE) and aberrations were evaluated on each patient. The patients were divided into three different groups according to the SE diopter before the surgery. We used the SAS and SPSS10.0 statistic software to analyze the data. RESULTS: Preoperatively, BCVA was 4.98 +/- 0.07. Ten days after surgery, UCVA and BCVA were 4.92 +/- 0.10 and 4.95 +/- 0.09, respectively. One month after surgery, UCVA and BCVA were 4.96 +/- 0.09 and 4.99 +/- 0.09, respectively. Over time, visual acuity improved with Postoperatively, parts of the eye's BCVA were better than preoperatively. Ten days after LASIK, the SE of three groups were hyperopic. But with time, SE changes to myopia. In the Allegretto exam, high order aberrations increased immediately after surgery in each group (P < 0.05), but decreased with time (P > 0.05) and did not return to preoperative values at one month. Preoperatively, the total aberrations (RMSg) were larger than postoperatively. The aberrations especially spherical are larger in the 6.5 mm pupil zone than in the 4 mm pupil zone. Preoperatively, there were no significant differences of high order aberrations between the three groups (P > 0.05). But after surgery, there were significant differences (P < 0.05). CONCLUSIONS: Initially, high order aberrations increased after LASIK, but decreased over time. Preoperatively, there were no significant differences of aberrations between the three groups, but after surgery, significant differences existed. The aberrations especially spherical were larger in the 6.5 mm pupil zone than in the 4 mm pupil zone. Allegretto wave-front analyzer can be used for low to middle myopia.