Altered organization of collagen in the apex of keratoconus corneas
Altered organization of collagen in the apex of keratoconus corneas
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DOI：
10.1159/000055492
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发表时间：
1998-09-01
影响因子：
2.1
通讯作者：
Mallinger, R
中科院分区：
文献类型：
--
作者：
Radner, W;Zehetmayer, M;Mallinger, R
目的：用扫描电子显微镜观察15例圆锥角膜中胶原板层的三维排列。方法：穿透性角膜移植获得无明显瘢痕的圆锥角膜。用氢氧化钠去除基质中的非胶原基质。Descemet的膜被机械地去除，通过用超微切割器切开与角膜表面相切的组织，暴露出更深层次的基质。圆锥角膜的顶端和近顶端区域与正常角膜的中心区域进行了比较。结果：15例圆锥角膜中，1例(73%)角膜根尖区胶原纤维排列不同于正常角膜及角膜根尖周区，胶原纤维排列均匀，未见分界胶原层。相邻层之间的交错非常少，甚至没有。圆锥角膜近端胶原层的三维排列与正常角膜无明显差异。结论：圆锥角膜顶端基质变薄和圆锥状扩张改变了胶原的组织结构。这肯定会影响角膜的生物力学特性，并进一步导致圆锥角膜的进展，无论其主要发病机制如何。
Purpose: In 15 keratoconus corneas, the three-dimensional arrangement of collagen lamellae was investigated by means of scanning electron microscopy. Methods: Keratoconus corneas without visible scars were obtained during perforating keratoplasty. The noncollagenous matrix of the stroma was removed with sodium hydroxide. Descemet's membrane was removed mechanically and deeper layers of the stroma were exposed by cutting the tissue tangentially to the corneal surface with an ultramicrotome. The apical and the para-apical regions of keratoconus were compared to the central regions of normal corneas. Results: In the apical regions of 1 l out of the 15 keratoconus corneas (73%), the arrangement of the collagen lamellae differs from those of the para-apical regions and normal corneas, Their collagen fibrils form uniform layers and no delimited collagen lamellae can be differentiated. Interlacing between adjacent layers is extremely decreased or even absent. In the para-apical region of keratoconus corneas the three-dimensional arrangement of collagen lamellae does not differ from that in normal corneas. Conclusion: Stromal thinning and conical ectasia in the apex of keratoconus corneas alters the organization of collagen. This will certainly affect the biomechanical properties of the cornea and further lead to a progression of keratoconus irrespective of its primary pathogenesis.