近视眼准分子激光角膜切削术后的对比敏感度评价

摘要

· AIM: To evaluate contrast sensitivity in patients who had undergone uncomplicated excimer laser photorefractive keratectomy (PRK) for myopia.· METHODS: Monocular contrast sensitivity function was measured with the CSV-I000E chart in 41 patients who had received PRK by the Nidek EC-5000 excimer laser system.Mean preoperative refractive error was -2.62±1.33 D (range,-0.75 to -4.00 D). Contrast sensitivity function was measured preoperatively, 1week, 1, 3 and 6months after surgery through the CSV-1000E contrast sensitivity unit (VectorVision).· RESULTS: Logarithmic values of contrast sensitivity at each spatial frequency were used for statistical analysis and normalized values were used for graphical representation.Contrast sensitivity decreased 1 week and 1 month postoperatively. Starting from the first month, there was rapid recovery of contrast sensitivity especially at low spatial frequencies, and at the third month, only at 6 and 12 cycles per degree (cpd) statistically significant decrease was seen.Six months after surgery, there was an increase in contrast sensitivity values at ail spatial frequencies.· CONCLUSION: Photorefractive keratectomy can induce significant reductions in contrast sensitivity in the first month after surgery; these values returned to the preopereative values at 6 months after surgery.%目的:评价近视患者PRK术后的对比敏感度变化.方法:应用CSV-1000E图表对41例接受Nidek EC-5000型准分子激光仪行PRK手术的患者,行单眼对比敏感度测量.患者术前平均屈光度为-2.62±1.33D(范围从-0.75至-4.00D).应用CSV-1000E对比敏感度仪分别在术前,术后1wk;1,3,6mo行对比敏感度检查.结果:将每个空间频率的对比敏感度对数值进行统计学分析,并应用图表与正常值进行比较.结果显示对比敏感度在术后1wk及术后1 mo时明显降低,从第1 mo开始,对比敏感度尤其是低空间频率的对比敏感度快速恢复,在第3mo,只有6和12cpd两种空间频率的对比敏感度明显降低,在术后6mo时,所有频率的对比敏感度功能都明显增加.结论:PRK术后患者第1 mo对比敏感度功能明显降低,但在术后6mo时对比敏感度功能即恢复至术前水平.