Mapping collagen organization in the human cornea: left and right eyes are structurally distinct.
OBJECTIVE
Aspects of the biomechanics and surface topography of fellow human corneas are known to exhibit midline symmetry, but the structural basis of these observations is poorly understood. The mechanical performance of the cornea is strongly influenced by the organization of stromal collagen fibrils. The present study was designed to examine and compare the organization of collagen fibrils in the corneal stroma of left and right eyes.


METHODS
Wide-angle x-ray scattering was used to map in detail the orientation and distribution of fibrillar collagen across the cornea, limbus, and adjacent sclera of three normal human eyes, including a fellow pair, and the central 9-mm corneal region of a further four eyes.


RESULTS
Fibrillar collagen in the human cornea and limbus is arranged anisotropically, and in a highly specific manner. Left and right corneas are structurally distinct. In general, the mass distribution of preferentially aligned fibrils in the cornea appears to exhibit a degree of midline symmetry between left and right eyes.


CONCLUSIONS
Structural information, such as that presented herein, will enable a better understanding of corneal biomechanics and shape. Midline symmetry in the distribution of aligned, mechanically reinforcing collagen fibrils between left and right eyes may relate to the biomechanical and topographical enantiomorphism reported in the literature.
Boote
Craig
C
Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom.
Hayes
Sally
S
Abahussin
Mohammad
M
Meek
Keith M
KM
D016880:Anisotropy; D001696:Biomechanical Phenomena; D003319:Corneal Stroma / Q000378:metabolism*; D019781:Corneal Topography; D024022:Fibrillar Collagens / Q000737:chemistry / Q000378:metabolism*; D007839:Functional Laterality; D006801:Humans; D014961:X-Ray Diffraction / Q000379:methods
D024022:Fibrillar Collagens