PDF(Pubmed)
Abstract：
Bowman\'s layer is an acellular layer in the anterior stroma found in the corneas of humans, most other primates, chickens, and some other species. Many other species, however, including the rabbit, dog, wolf, cat, tiger, and lion, do not have a Bowman\'s layer. Millions of humans who have had photorefractive keratectomy over the past thirty plus years have had Bowman\'s layer removed by excimer laser ablation over their central cornea without apparent sequelae. A prior study showed that Bowman\'s layer does not contribute significantly to mechanical stability within the cornea. Bowman\'s layer does not have a barrier function, as many cytokines and growth factors, as well as other molecules, such as EBM component perlecan, pass bidirectionally through Bowman\'s layer in normal corneal functions, and during the response to epithelial scrape injury. We hypothesized that Bowman\'s layer represents a visible indicator of ongoing cytokine and growth factor-mediated interactions that occur between corneal epithelial cells (and corneal endothelial cells) and stromal keratocytes that maintain the normal corneal tissue organization via negative chemotactic and apoptotic effects of modulators produced by the epithelium on stromal keratocytes. Interleukin-1 alpha, produced constitutively by corneal epithelial cells and endothelial cells, is thought to be one of these cytokines. Bowman\'s layer is destroyed in corneas with advanced Fuchs\' dystrophy or pseudophakic bullous keratopathy when the epithelium becomes edematous and dysfunctional, and fibrovascular tissue commonly develops beneath and/or within the epithelium in these corneas. Bowman\'s-like layers have been noted to develop surrounding epithelial plugs within the stromal incisions years after radial keratotomy. Although there are species-related differences in corneal wound healing, and even between strains within a species, these differences are not related to the presence or absence of Bowman\'s layer.
摘要：
Bowman层是人类角膜前基质中的无细胞层，大多数其他灵长类动物，鸡,和其他一些物种。许多其他物种,然而,包括兔子,狗,狼,猫,老虎,狮子,没有鲍曼的层。在过去的三十多年中，数百万接受过光屈光性角膜切除术的人已经通过准分子激光消融在其中央角膜上去除了Bowman层，没有明显的后遗症。先前的研究表明Bowman层对角膜内的机械稳定性没有显著贡献。Bowman\的层没有屏障功能，就像许多细胞因子和生长因子一样，以及其他分子，例如EBM组件perlecan，在正常的角膜功能中双向穿过Bowman层，以及在对上皮刮伤的反应期间。我们假设Bowman层代表了角膜上皮细胞（和角膜内皮细胞）和基质角膜细胞之间正在发生的细胞因子和生长因子介导的相互作用的可见指标，通过上皮对基质角膜细胞产生的调节剂的负趋化和凋亡作用维持正常角膜组织组织。白细胞介素-1α,由角膜上皮细胞和内皮细胞组成，被认为是这些细胞因子之一。当上皮变得水肿和功能失调时，患有晚期Fuchs营养不良或假性晶状体大疱性角膜病变的角膜中的Bowman层被破坏，和纤维血管组织通常在这些角膜的上皮下方和/或内发育。据发现，在放射状角膜切开术后数年，在基质切口内，鲍曼样层会形成周围的上皮塞。尽管角膜伤口愈合存在物种相关差异，甚至在一个物种内的菌株之间，这些差异与鲍曼层的存在与否无关。
