Glaucoma, << glaw KOH muh, >> is an eye disease characterized by increased pressure of the fluid within the eye. Glaucoma is a leading cause of blindness in the United States and worldwide.
The clear, watery fluid inside the eye is produced by cells behind the iris. The fluid circulates between the lens and the cornea, providing nourishment to these tissues. Normally, the fluid drains through tiny channels into the blood vessels leading away from the eye. If a blockage occurs at any point in the fluid’s pathway, pressure within the eye increases, producing glaucoma. Blindness results when this pressure destroys the optic nerve, which connects the eye to the brain.
The most common type of glaucoma is primary open-angle glaucoma, also known as chronic simple glaucoma. It occurs mainly in people over 40 years old and may be inherited. It often advances unnoticed because it does not cause pain or other obvious symptoms. The person’s vision may slowly narrow until he or she is blind. There is no cure for this type of glaucoma, but most cases can be controlled with drugs. A doctor may also form a new drainage pathway for the eye’s fluid through surgery or by using a high-energy light from a laser. In addition, doctors have used ultrasound (high-frequency sound waves) to treat primary open-angle glaucoma. Such treatment reduces the amount of fluid produced in the eye.
Another type of glaucoma, known as primary narrow-angle glaucoma or acute glaucoma, may occur suddenly and at any age. Symptoms include seeing rainbowlike rings around lights, redness of the eye, and severe pain in the eyes and forehead. Blindness results unless the person is immediately treated with drugs, surgery, or laser therapy.
Glaucoma sometimes occurs as a result of other disorders or conditions. These include internal inflammation of the eye, diseases of the lens of the eye, injury to the eye, or complications of eye surgery. A doctor can usually cure such secondary glaucomas by treating the underlying disorder.
