Abbas U L, Hersh P S
Department of Ophthalmology, UMDNJ-New Jersey Medical School, Newark 07103, USA.
Ophthalmology. 1998 Dec;105(12):2197-206. doi: 10.1016/S0161-6420(98)91216-7.
To investigate the natural history of corneal topography after excimer laser photorefractive keratectomy (PRK).
A prospective, single center clinical study.
A total of 40 eyes of 34 patients with myopia were studied.
Excimer laser photorefractive keratectomy and computer-assisted videokeratography were performed.
Preoperative, 1 week, and 1, 2, and 3 months postoperative topography patterns were compared and changes assessed by averaging defined sectors of the ablation zone in individual maps to produce composite "average" topography maps.
Corneal topography was generally not homogeneous at 1 week after PRK. By 3 months, there had been considerable smoothing of corneal contour. A general "central island" effect early in the postoperative period flattened over time. When right and left eyes were evaluated independently, a tendency toward a keyhole-semicircular pattern was seen on average; the maximum flattening was nasal and the least flattening was inferotemporal for both right and left eyes.
A tendency, on average, toward central island and keyhole-semicircular patterns is seen early in the postoperative course after PRK. Central islands tend to evolve into the keyhole-semicircular pattern, and the corneal topography in general after PRK tends to smooth considerably with time.
研究准分子激光屈光性角膜切削术（PRK）后角膜地形图的自然转归。
一项前瞻性单中心临床研究。
共研究了34例近视患者的40只眼。
实施准分子激光屈光性角膜切削术及计算机辅助的视频角膜地形图检查。
比较术前、术后1周以及术后1、2和3个月的地形图模式，并通过对各张地形图中消融区的特定扇形区域求平均值来评估变化，以生成复合“平均”地形图。
PRK术后1周角膜地形图通常不均匀。到3个月时，角膜轮廓有了明显的平滑。术后早期普遍存在的“中央岛”效应随时间逐渐变平。当分别评估右眼和左眼时，平均呈现出钥匙孔 - 半圆形模式的趋势；右眼和左眼的最大变平均位于鼻侧，最小变平位于颞下侧。
PRK术后早期平均呈现出中央岛和钥匙孔 - 半圆形模式的趋势。中央岛往往会演变成钥匙孔 - 半圆形模式，并且PRK术后角膜地形图总体上会随着时间显著变平滑。
