Glaucoma: changes in extracellular matrix in the optic nerve head.

Primary open angle glaucoma (POAG), the most common form of glaucoma, is characterized by irreversible loss of axons from the optic nerve. The site of damage to the axons is at the level of the lamina cribrosa in the optic nerve head. It has been hypothesized that structural and biochemical abnormalities in the extracellular matrix (ECM) of the lamina cribrosa underlie the progressive compressive and remodelling of this connective tissue in glaucoma. In this review, we present evidence of specific changes in collagen and elastic fibers, major ECM components in the lamina cribrosa of glaucomatous eyes.