Fig. 5

Fibril orientation and distribution level. All collagen of the stroma is organized in microstructures called lamellae, that run rather parallel to the mid surface of the cornea. Almost 60% of the resulting collagen fibrils distribution are uniformly dispersed, leading to an isotropic behavior. The remaining 40% is instead oriented in specific directions. a According to X-ray diffraction findings, at the center of the cornea collagen is organized in an orthogonal configuration, and at the limbus it runs circumferentially, although it is requested the presence of radial fibrils to guarantee the integrity of the body. b Maps of the coefficient b that defines the level of the anisotropy of 40% of the stromal fibrils. A small value of b corresponds to an isotropic distribution, a large value b>2 correspond to a marked anisotropy