[Fibrous structure of connective tissue of normal human lamina cribrosa]

Fibrous components and structural morphology of the connective tissue of the lamina cribrosa obtained from 35 normal human autopsy eyes were examined by histochemical staining, transmission electron microscopic and computer-assistant image analytical techniques. Principles of biomechanics were used onto the lamina cribrosa in characterizing its structural and mechanical properties, and in investigating its damage forms, intermediary role between intraocular pressure and optic nerve damage, and intervening factors. We came to the following conclusions: The laminar bundles contain all the three kinds of fibers and behave in such triplex properties as elasticity, plasticity and stiffness. The ellipse shaped transverse section of the lamina cribrosa with the long axis at the vertical meridian, the quadrant variations in the course and density of laminar bundles, and the interindividual variations in the thickness of the lamina cribrosa are responsible for the damage-resistant ability of lamina cribrosa. The intraocular pressure exerts effects upon the lamina cribrosa through two ways, and the damage of the lamina cribrosa is the intermediate link between the insults of the intraocular pressure and the optic nerve damage.