Collagen and mature elastic fibre organisation as a function of depth in the human cornea and limbus.
A network of circumferentially oriented collagen fibrils exists in the periphery of the human cornea, and is thought to be pivotal in maintaining corneal biomechanical stability and curvature. However, it is unknown whether or not this key structural arrangement predominates throughout the entire corneal thickness or exists as a discrete feature at a particular tissue depth; or if it incorporates any elastic fibres and how, with respect to tissue depth, the circumcorneal annulus integrates with the orthogonally arranged collagen of the central cornea. To address these issues we performed a three-dimensional investigation of fibrous collagen and elastin architecture in the peripheral and central human cornea using synchrotron X-ray scattering and non-linear microscopy. This showed that the network of collagen fibrils circumscribing the human cornea is located in the posterior one-third of the tissue and is interlaced with significant numbers of mature elastic fibres which mirror the alignment of the collagen. The orthogonal arrangement of collagen in the central cornea is also mainly restricted to the posterior stromal layers. This information will aid the development of corneal biomechanical models aimed at explaining how normal corneal curvature is sustained and further predicting the outcome of surgical procedures.
Kamma-Lorger
Christina S
CS
Structural Biophysics Research Group, School of Optometry and Vision Sciences, Maindy Road, Cardiff University, Cardiff CF24 4LU, UK.
Boote
Craig
C
Hayes
Sally
S
Moger
Julian
J
Burghammer
Manfred
M
Knupp
Carlo
C
Quantock
Andrew J
AJ
Sorensen
Thomas
T
Di Cola
Emanuela
E
White
Nick
N
Young
Robert D
RD
Meek
Keith M
KM
D003094:Collagen / Q000378:metabolism / Q000502:physiology*; D003315:Cornea / Q000378:metabolism / Q000502:physiology*; D004547:Elastic Tissue / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D016850:Limbus Corneae / Q000378:metabolism / Q000502:physiology*; D008853:Microscopy; D014961:X-Ray Diffraction
D003094:Collagen