Collagen fibrils appear more closely packed in the prepupillary cornea: Optical and biomechanical implications
Collagen fibrils appear more closely packed in the prepupillary cornea: Optical and biomechanical implications
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DOI：
10.1167/iovs.03-0131
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发表时间：
2003-07-01
影响因子：
4.4
通讯作者：
Meek, KM
中科院分区：
文献类型：
--
作者：
Boote, C;Dennis, S;Meek, KM
目的。基质胶原原纤维的大小和组织影响角膜的生物力学和光学特性，从而影响其功能。纤维结构如何随角膜位置的变化尚未得到充分表征。本研究旨在量化正常人角膜上的胶原原纤维间距和直径，并将其与组织的特性联系起来。方法。使用小角 X 射线衍射详细绘制了五个正常人角巩膜盘沿正交内侧-外侧和下-上经线的原纤维间距和原纤维直径的变化。结果。所有角膜直至角膜缘的平均原纤维直径保持恒定，随后观察到急剧增加。然而，中央 4 X 3 毫米（瞳孔前）角膜的平均原纤维间距比周边角膜低 5% 至 7%。结论。瞳孔前角膜中的胶原纤维似乎比周边角膜中的胶原纤维排列得更紧密。角膜上原纤维堆积的各向异性对组织的透明度和折射率具有潜在影响。从生物力学角度来看，瞳孔前角膜中承受压力的胶原原纤维的较高堆积密度可能是维持角膜强度所必需的，因此在组织厚度减小的区域中维持曲率是必要的。由此推断，这些结果可能对屈光手术角膜模型的开发具有重要意义。 （投资眼科可见科学。2003 年；44：2941-2948）DOI：10.1167/iovs.03-0131。
PURPOSE. The size and organization of stromal Collagen fibrils influence the biomechanical and optical properties of the cornea and hence its function. How fibrillar structure varies with position across the cornea has not been fully characterized. The present study was designed to quantify the Collagen fibril spacing and diameter across the normal human cornea and to relate this to the properties of the tissue.METHODS. Small-angle x-ray diffraction was used to map in detail the,variation in fibril spacing and fibril diameter along orthogonal medial-lateral and inferior-superior meridians of five normal human corneoscleral discs.RESULTS. Mean fibril diameters remained constant across all corneas up to the limbus, whereupon a sharp increase was observed. However, mean fibril spacing across the central 4 X 3 mm (prepupillary) cornea measured 5% to 7% lower than in the peripheral cornea.CONCLUSIONS. Collagen fibrils in the prepupillary cornea appear to be more closely packed than in the peripheral cornea. Anisotropy in fibril packing across the cornea has potential implications for the transparency and refractive index of the tissue. Biomechanically, it is possible that the higher packing density of stress-bearing Collagen fibrils in the prepupillary cornea is necessary for maintaining corneal strength, and hence curvature, in a region of reduced tissue thickness. By inference, these results could have important implications for the development of corneal models for refractive surgery. (Invest Ophthalmol Vis Sci. 2003;44:2941-2948) DOI: 10.1167/iovs.03-0131.