No single factor has been identified as a cause of chronic open-angle glaucoma. A number of conditions, alone or in combination, are needed to trigger the processes leading to pressure in the first place and then to the nerve damage that destroys sight. Causes of Intraocular Pressure. The aging process may contribute to the pressure in chronic open-angle glaucoma by decreasing the number or activity of the cells in the trabecular mesh, impairing their ability to drain the aqueous fluid effectively. Deficiencies in nitric oxide, a molecule that is critical for healthy blood vessels, may contribute to glaucoma.
Genetic factors play a role in a small number of glaucoma cases.
People with these genetic defects often develop abnormally high pressure at much younger ages than those with standard glaucomas. Another gene called LMX1B causes a rare condition called nail-patella syndrome, which is marked by abnormal development of tissues in the nails, elbows, and knees, and is now believed to also cause certain cases of glaucoma. Causes of Damage in the Optic Nerve. Among the conditions that can injure fibers in the optic nerve are nutritional deficiencies, compression on the nerves, toxic factors, or abnormalities in chemicals in the brain that cause the cells in nerve fibers to die. In large amounts, glutamate can cause severe damage by excessive firing of these nerves.