Why does intra-ocular pressure rise?

The aqueous humor is produced in the ciliary body and it is cleared through the trabecular meshwork and the uveo-scleral pathway. Aside from its nourishing properties, it is responsible for maintaining adequate tone inside the eye. In order for this to occur, there needs to be a balance between the amount of fluid produced and the amount that is cleared.

When there is interference at some point along the path through which the aqueous must flow, it accumulates leading to reduced clearing and a rise in intra-ocular pressure. As a result of this rise, there is an increased cupping of the optic nerve because of fiber damage that creates a visual field loss that starts at the periphery. As it advances, it reduces the visual field concentrically, slowly leading to reduced frontal vision known as “tubular vision” that may result in irreversible blindness if not controlled on time.