经上皮准分子激光角膜切削术治疗不规则角膜散光的视觉质量观察

目的观察对不规则角膜散光患者施行角膜地形图引导的经上皮准分子激光角膜切削术后患者视觉质量的改善情况。方法非随机前瞻性临床研究。收集不规则角膜散光患者12例（15眼），施行角膜地形图引导的经上皮准分子激光角膜切削术，观察术前及术后1个月、3个月患者UCVA、BCVA、屈光状态、对比敏感度，记录术后角膜haze出现的时间与分级，以及安全性、有效性指数。数据采用重复样本的方差分析进行比较。结果①UCVA均值术前为4.11±0.28，到术后3个月提高至4.88±0.16（F=36.706，P＜0.05）；BCVA均值术前为4.86±0.08，到术后个3月提高至4.98±0.09（F=5.075，P＜0.05），且无一眼视力较术前下降；手术治疗的安全性指数为1.025，有效性指数为1.004。②术前平均等效球镜度与平均柱镜度分别由术前的（-3.73±4.62）D、（-1.71±1.43）D，下降至术后3个月的（-0.03±0.09）D（F=-4.034，P＜0.05）、（-0.38±1.14）D，（F=-9.192，P＜0.05）。③术后3个月3、6、12 c/d 3种空间频率对比敏感度与术前相比均明显提高（P＜0.05）。④术后1个月haze出现2例，到术后3个月时全部消退。结论角膜地形图引导的经上皮准分子激光角膜切削术可以有效矫正不规则角膜散光；改善不规则角膜散光患者的对比敏感度，提高患者视觉质量。

An evaluation of visual performance after trans-epithelial photorefractive keratectomy for correcting irregular corneal astigmatism

Objective To evaluate visual performance pre-and postoperatively in patients with irregular corneal astigmatism who were treated with topography-guided trans-epithelial photorefractive keratectomy （TPRK）.Methods This non-randomized prospective clinical study was comprised of 15 eyes of 12 patients with irregular corneal astigmatism who were treated with topography-guided TPRK.The data included UCVA,BCVA,pre-and postoperative refractive data,and contrast sensitivity before surgery and at 1 and 3 months after surgery,the corneal epithelial timeline for healing,pain scores at 3 and 7 days after surgery,the classification of haze when it appeared,and the safety and efficacy indexes.Repeated measures analysis of variance was used to compare the changes over time.Results Mean UCVA increased from 4.11±0.28 preoperatively to 4.88±0.16 3 months postoperatively （F=36.706,P＜0.05）.Mean BSCVA increased from 4.86±0.08 to 4.98±0.09 （F=5.075,P＜0.05）,with no visual acuity lines lost.Safety and efficacy indexes were 1.025 and 1.004,respectively.Mean spherical equivalent （SE） was reduced from-3.73±4.62 D to-0.03±0.09 D （F=-4.034,P＜0.05）,and the mean cylinder was reduced from-1.71±1.43 D to ＋0.38±1.14 D （F=-9.192,P＜0.05）.Tbere were significant differences in contrast sensitivity were found between patients at 3,6,12 c/d spatial frequencies before surgery and 1 month after surgery （P＞0.05）.But patients at 3 months after surgery showed better contrast sensitivity than patients before surgery （P＜0.05）.Haze appeared in 2 eyes at 1 month postoperatively but recovered by 3 months postoperatively.Conclusion Topography-guided TPRK appears to be an effective treatment for irregular corneal astigmatism.The operation improves contrast sensitivity and visual performance in patients with irregular corneal astigmatism.