Changes in collagen orientation and distribution in keratoconus corneas.

Purpose: To map the collagen orientation and relative distribution of collagen fibrillar mass in keratoconus corneal buttons.

Methods: Structural analysis was performed by obtaining synchrotron x-ray scattering patterns across the samples at 0.25-mm intervals.

X-ray scattering used to map the preferred collagen orientation in the human cornea and limbus.

Many properties of connective tissues are governed by the organization of the constituent collagen. For example, the organization of collagen in the cornea and the limbus, where the cornea and sclera meet, is an important determinant of corneal curvature and hence of the eye's focusing power. We have used synchrotron X-ray scattering to map the orientation of the collagen fibrils throughout the human cornea, limbus, and adjacent sclera.

Collagen fibrils appear more closely packed in the prepupillary cornea: optical and biomechanical implications.

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.