Why does pressure rise in the eye to cause glaucoma?

Eye fluid imbalance: Glaucoma is caused by damage to the optic nerve due to increased pressure in the eye. The increased pressure can be due to increased fluid production or decreased drainage. Sometimes the reason for the increased pressure is not known. People over the age of 40, with diabetes, eye injury or eye surgery are at increased risk of glaucoma. Glaucoma is also more common among african americans.

Eye fluid imbalance: Fluid flows from the globe of the eye and travels out the area of the pupil. An imbalance in either overproduction or decreased drainage can cause the elevated pressures in the eye. Other causes include medication use that affects the drainage of the fluid.

Plumbing problem: Fluid is made in the ciliary body and exists the trabecular meshwork drain. If more aqueous fluid fills the globe and can't exit fast enough, then the eye pressure will increase. This ocular pressure is transmitted back to the optic nerve head and causes mechanical strain leading to glaucomatous changes and cell death. Other factors are thought to be involved.