Purchase this article with an account.
K.M. Meek, C. Boote, A.J. Quantock, S. Dennis, H. Aghamohammadzadeh, R.H. Newton; The fibrillar arrangement and distribution of collagen in normal human corneas. . Invest. Ophthalmol. Vis. Sci. 2004;45(13):3826.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To understand the gross lamellar organisation throughout the human cornea and limbus. Methods: : Small and wide–angle synchrotron x–ray scattering was carried out at the European Synchrotron Radiation Facility (ESRF) at Grenoble, France and at the Synchrotron Radiation Source (SRS) at Daresbury, U.K. respectively. Scattering patterns were recorded at intervals across the human cornea and limbus. The patterns were analysed to produce: 1. polar plots showing the predominant orientation of lamellae throughout the tissue; 2. scattering intensity maps to show the distribution of total and preferentially–aligned collagen mass; 3. plots showing the variation of the major inter–lamellar angle along selected meridia. Results: Collagen orientation maps confirm the predominance of vertically and horizontally disposed fibrils across most of the cornea, but these are seen to change direction to run tangentially or circumferentially at the limbus. The inter–lamellar angle and collagen mass plots strongly support the concept that collagen fibrils can change direction in a plane parallel to the corneal surface. Total collagen mass increases from the central cornea in a circularly symmetrical manner, whereas the distribution of preferentially aligned collagen is circular in the pre–pupillary cornea but diamond–shaped in the peripheral cornea. Conclusions: We believe that lamellae change direction as they course across the cornea (possibly by bifurcating) and that many of the posterior lamellae do this as they approach the limbus. We propose a model in which additional lamellae curve in and out of the peripheral cornea such that they do not cross the prepupillary region. Most of these extra lamellae have a preferential orientation and may aid the flattening known to occur in the peripheral cornea outside the main optical zone.
This PDF is available to Subscribers Only