Levin S, Carson C A, Garrett S K, Taylor H R
Department of Ophthalmology, University of Melbourne, Victoria, Australia.
J Cataract Refract Surg. 1995 Jan;21(1):21-6. doi: 10.1016/s0886-3350(13)80474-9.
We conducted a study to determine the prevalence of central islands after refractive excimer laser surgery and the factors associated with their occurrence. A VISX Twenty/Twenty excimer laser was used to perform 157 photorefractive keratectomy (PRK) and 263 photorefractive astigmatic keratectomy (PARK) procedures. Corneal topography was assessed in 156 patients three months postoperatively using a topographic analysis system. Central islands were seen in 67% of patients; 26% had islands of 3.0 diopters (D) or more in height. Occurrence was associated with the laser suction nozzle being fixed during the procedure (P < .05). There was no demonstrable effect of central islands on visual acuity or refractive outcome, nor was there any relation to the amount of attempted correction or type of procedure (PARK or PRK). Central islands with a curvature difference of less than 3.0 D were seen more frequently than an absence of islands, suggesting these may be a "normal" postoperative topographic variation. The effect of nozzle position on island formation suggests that plume removal or corneal hydration may be important, as is corneal epithelial healing.
我们开展了一项研究，以确定准分子激光屈光手术后中央岛的发生率及其相关因素。使用VISX Twenty/Twenty准分子激光进行了157例光性屈光性角膜切削术（PRK）和263例光性屈光性散光角膜切削术（PARK）。术后三个月，使用地形分析系统对156例患者进行了角膜地形图评估。67%的患者出现中央岛；26%的患者中央岛高度达到或超过3.0屈光度（D）。中央岛的出现与手术过程中激光吸嘴固定有关（P < 0.05）。中央岛对视敏度或屈光结果无明显影响，与预期矫正量或手术类型（PARK或PRK）也无关联（P > 0.05）。曲率差异小于3.0 D的中央岛比无中央岛的情况更常见，提示这可能是一种“正常”的术后地形变化。吸嘴位置对中央岛形成的影响表明，去除羽流或角膜水化可能很重要，角膜上皮愈合也是如此。
