Fig. 7.

Schematic diagram of the proposed elastic fiber network in the corneal stroma. Elastic fibers consisting of predominantly fibrillin microfibrils sheathing an amorphous elastin core occur pseudo-circumferentially in the limbus and become more like sheets, then broad fibers towards the cornea (black lines). As the fibers continue towards the center of the stroma, they become thinner and start to lose their elastic cores (grey). In the central optical zone of the cornea, there is little or no elastin and most fibers become fibrillin-rich bundles of microfibrils (pale grey). In the keratoconus central cornea, the MBs are greatly depleted so the potential connections across the cornea are reduced and, we propose, the cornea is subsequently weakened.