Webber S K, McGhee C N, Bryce I G
Corneal Diseases and Excimer Laser Unit, Sunderland Eye Infirmary, England.
J Cataract Refract Surg. 1996 Apr;22(3):299-303. doi: 10.1016/s0886-3350(96)80239-2.
To devise a method for measuring excimer laser photorefractive keratectomy (PRK) ablation zone decentration.
Excimer Laser Clinic, Sunderland Eye Infirmary, Sunderland Tyne and Wear, England.
Fifty-three eyes of 53 consecutive patients having PRK for a spherical myopic refractive error were studied. Preoperative and postoperative corneal topographic maps and differential subtraction maps were produced for each cornea. Using these maps, the distance between ablation zone centers and pupil centers was measured. All measurements were repeated by a second observer.
Mean ablation zone decentration was 0.46 mm from the pupil center; 69% of cases decentered 0.50 mm or less. The difference between the two independent measurements was 0.05 +/- 0.06 mm (mean +/- SD). A trend toward superonasal displacement was noted.
This simple method of measuring zone decentration can be used to compare the refractive results of PRK with those of other procedures.
设计一种测量准分子激光屈光性角膜切削术（PRK）消融区偏心的方法。
英国泰恩-威尔郡桑德兰市桑德兰眼科医院准分子激光诊所。
对连续53例因单纯近视性屈光不正接受PRK治疗的患者的53只眼进行研究。为每只角膜制作术前和术后角膜地形图及差分减法图。利用这些图测量消融区中心与瞳孔中心之间的距离。所有测量均由另一位观察者重复进行。
消融区平均偏心距瞳孔中心0.46mm；69%的病例偏心距在0.50mm或以下。两次独立测量的差异为0.05±0.06mm（平均值±标准差）。观察到有向鼻上移位的趋势。
这种测量区域偏心的简单方法可用于比较PRK与其他手术的屈光结果。
