What Is Glaucoma?
Glaucoma is the term for several different conditions of the eye that causes damage to the optic nerve, according to the U.S. National Library of Medicine. Glaucoma occurs when fluid accumulates in the eyeball, increasing the pressure and causing damage that can eventually lead to blindness if not treated. It doesn't cause any symptoms until vision is lost, says the American Academy of Family Physicians, so regular eye exams are important, particularly for people age 64 and older.
Fluid Buildup
Fluid buildup that leads to glaucoma can occur for several different reasons. In angle-closure glaucoma, the iris pushes forward and blocks the drainage opening, leading to fluid and pressure buildup. Low-tension glaucoma has an unknown cause, but it's thought to occur because of sensitivity in the optic nerve or insufficient blood supply due to atherosclerosis, says the Mayo Clinic. Pigmentary glaucoma is caused by granules of pigment that build up inside the eye, preventing the discharge of aqueous fluid and increasing pressure.
Family History and Other Causes
Congenital glaucoma is another type, says the NLM, and it strikes at birth--not in older people. It's caused by hereditary factors that lead to an abnormality in the outflow ducts in the eye. Systemic health conditions--which affect the entire body, the eye disease uveitis and taking corticosteroid medications can also cause glaucoma, says the NLM.
