Fig 7. Simplified mechanism of collagen crosslinking with and without soluble collagen in collagenase treated corneas.

(A) Ectatic corneas with ultrastructural damages, (B) Crosslinking without soluble collagen happens between proteoglycan and collagen fibrils, and also between collagen molecules, and proteoglycan interfigril; (C) Crosslinking with soluble collagen happens not only between native collagen fibril and proteoglycans, but also between soluble collagen and native collagen, and soluble collagen and proteoglycan.