Frueh B E, Cadez R, Böhnke M
Department of Ophthalmology, Inselspital, University of Berne, Switzerland.
Arch Ophthalmol. 1998 Nov;116(11):1425-31. doi: 10.1001/archopht.116.11.1425.
To assess corneal morphological characteristics in vivo after photorefractive keratectomy (PRK) in humans.
Eighteen eyes were examined before and after PRK by means of in vivo confocal microscopy. Epithelial, stromal, and endothelial morphological characteristics were recorded. Minimum follow-up was 12 months.
Immediately after PRK, the anterior stroma showed marked intercellular edema. At 1 month, fine linear structures were noted in the anterior stroma and midstroma, and a thin hyperreflective scar was present. The linear structures and the scar tissue were more marked at 4 months but were still present up to 26 months. Anterior stromal keratocyte density increased significantly 1 and 4 months after PRK, whereas midstromal and posterior keratocytes and endothelial cell densities did not change. Basal epithelial nerves were recognizable as early as 1 month after PRK. Contact lens-related microdots in the stroma remained unaffected.
The stromal linear structures represent a finding that is detectable only by confocal microscopy at high magnification, is not related to previous contact lens wear, and is still visible 26 months after PRK. The extension of these structures as far as the midstroma indicates that the permanent corneal changes caused by PRK affect deeper stromal layers than the immediate subepithelial region.
评估人类准分子激光角膜切削术（PRK）后角膜的活体形态特征。
采用活体共聚焦显微镜对18只眼在PRK术前和术后进行检查。记录上皮、基质和内皮的形态特征。最短随访时间为12个月。
PRK术后即刻，前基质显示明显的细胞间水肿。术后1个月，在前基质和基质中层可见细微的线性结构，并有一条薄的高反射瘢痕。这些线性结构和瘢痕组织在术后4个月时更明显，但直至26个月时仍存在。PRK术后1个月和4个月时，前基质角膜细胞密度显著增加，而基质中层和后层角膜细胞以及内皮细胞密度未发生变化。PRK术后1个月时即可识别出基底上皮神经。基质中与隐形眼镜相关的微点未受影响。
基质线性结构是一种仅在高倍共聚焦显微镜下可检测到的表现，与既往隐形眼镜佩戴无关，且在PRK术后26个月时仍可见。这些结构延伸至基质中层表明，PRK引起的角膜永久性改变影响的基质层比紧邻上皮下区域更深。
