Glaucoma is a vision-threatening disorder characterized by slow loss of optic nerve fibers. Susceptibility to this disease depends on a variety of factors including the level of pressure in the eye, a genetic tendency and older age. Glaucoma sometimes is caused by an abnormal buildup of a clear fluid called aqueous humor inside the eyeball. Normally drained away and replaced by the eye, the fluid is critical for bringing nutrients to the lens and cornea and removing waste material. When drainage channels become blocked, the increased pressure in the eye can damage the optic nerve. Glaucoma often develops slowly and painlessly (open-angle), or occasionally, suddenly and painfully (closed-angle). Open-angle glaucoma strikes two percent of older Caucasians and eight percent of older African Americans. People who have a family history of glaucoma have a higher-than-normal risk of disease. Although open-angle glaucoma cannot be prevented, early diagnosis gives physicians a valuable advantage in treatment to reduce the chance of blindness.
Two valuable testing procedures such as photographic quantitation of the nerve fiber layer, which indicates the health of the eye and the very latest visual field testing devices and computerized techniques are essential for early diagnosis. The tonometer, a device that measures pressure in the eye, show that the amount of daily fluctuation in pressure can predict the likelihood of vision loss. Such tests can lead to early treatment before obvious vision problems materialize.
Treatment for glaucoma may include eye drops to decrease production of the fluid aqueous humor. Eye drops also may promote outflow from the front part of the eye into small drainage canals, thereby lowering pressure. Glaucoma that is resistant to drug treatment can be treated with argon laser trabeculoplasty, an outpatient procedure using a laser beam. A surgical technique called trabeculectomy also may be performed to lower eye pressure.