Steinert R F
Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA.
Trans Am Ophthalmol Soc. 1997;95:629-714.
To further the understanding of wound healing anomalies affecting visual function after myopic photorefractive keratectomy (PRK).
Analysis of a clinical database of PRK on 133 eyes with myopia of -1.5 to -7.0 D and 43 eyes with myopia of -6.0 to -12.0 D. Visual function was analyzed by subgroups of 1) no topographic anomalies; 2) topographic central islands; and 3) topographic keyhole patterns. The natural course of healing was documented over 6 months with visual acuity measurements, clinical observation, and corneal topography. In vivo clinical-pathologic correlations were made by scanning confocal microscopy.
Topographic anomalies were identified 1 month post-PRK in 48 eyes (40.3%) with low-moderate myopia and in 14 eyes (32.5%) with moderate-high myopia. For patients with 6 month follow-up, these rates declined to 25% and 23%, respectively. At 1 month post-PRK, topographic anomalies significantly reduced uncorrected and best-corrected visual acuity and refractive predictability. By 6 months post-PRK, the small number of eyes with persistent anomalies had visual outcomes similar to patients with normal topography. A simple approach to anti-island pre-treatment reduced islands slightly and keyhole anomalies significantly (anti-island pre-treatment vs no pretreatment: islands 25% vs 31.8%; keyholes 2.3% vs 17.6%; p = 0.021) but with decreased predictability of induced refractive change at 1 month post-PRK. Confocal microscopy in vivo demonstrated prominent deposition of subepithelial extracellular material 1 to 2 months after PRK that diminished by 6 to 8 months, but persisted in the presence of central islands. Scar formation appeared to represent an elevated plaque of new collagen with active keratocytes.
Topographic anomalies of wound healing are common after PRK. Vision and predictability are reduced by anomalies 1 month post-PRK but anomalies often resolve by 6 months. Marked improvement of vision occurs even when anomalies persist. Central islands appear to consist of persistent dense subepithelial extracellular deposits. Local scars are caused by new collagen deposition.
进一步了解影响近视性准分子激光原位角膜磨镶术（PRK）后视觉功能的伤口愈合异常情况。
分析133只近视度数在-1.5至-7.0D的眼睛以及43只近视度数在-6.0至-12.0D的眼睛的PRK临床数据库。视觉功能按以下亚组进行分析：1）无地形异常；2）地形性中央岛；3）地形性钥匙孔图案。通过视力测量、临床观察和角膜地形图记录6个月内的自然愈合过程。通过共聚焦显微镜扫描进行体内临床病理相关性分析。
PRK术后1个月，48只（40.3%）中低度近视眼睛和14只（32.5%）中高度近视眼睛出现地形异常。在随访6个月的患者中，这些比例分别降至25%和23%。PRK术后1个月，地形异常显著降低了未矫正和最佳矫正视力以及屈光预测性。到PRK术后6个月，少数仍有持续异常的眼睛的视觉结果与地形正常的患者相似。一种简单的抗岛预处理方法可使中央岛略有减少，钥匙孔异常显著减少（抗岛预处理与未预处理：中央岛25%对31.8%；钥匙孔2.3%对17.6%；p = 0.021），但在PRK术后1个月诱导屈光变化的预测性降低。共聚焦显微镜体内检查显示，PRK术后1至2个月上皮下细胞外物质有明显沉积，6至8个月时减少，但在中央岛存在时持续存在。瘢痕形成似乎表现为新胶原与活跃角膜细胞组成的隆起斑块。
PRK术后伤口愈合的地形异常很常见。PRK术后1个月，异常会降低视力和预测性，但异常情况通常在6个月时消退。即使异常持续存在，视力也会有显著改善。中央岛似乎由持续存在的致密上皮下细胞外沉积物组成。局部瘢痕是由新胶原沉积引起的。
