The second leading cause of blindness among Americans is glaucoma. An estimated 3 million Americans age 40 and over have glaucoma, and it affects 3% of people age 65 and over. Studies show that glaucoma is three to four times more likely to occur in African Americans and about six times more likely to cause blindness in blacks than in whites.

Glaucoma is a painless eye disorder that occurs when pressure (ocular hypertension) builds up within the eye because of resistance to aqueous humor outflow from the chamber of the eye. It causes a insidious and progressive loss of vision as the optic nerve and retina are damaged. Central visual acuity can remain normal for a long time while vision in the peripheral field gradually constricts.

Up to 40 percent of the optic nerve fibers may be destroyed before glaucoma is detected using standard techniques (Brocklehurst). If glaucoma goes undetected and untreated it causes permanent visual impairment. Anyone can get glaucoma, but African Americans, older adults, and those with a family history are at greater risk.

Risk Factors for Glaucoma

• African Americans over age forty
• Persons age 60 and older
• Family history

Treatment

The goal of medical treatment is to lower intraocular pressure. Until recently, the medical treatment of glaucoma required using as many as four eye drops, plus oral medications. Often effective control was not achieved and patients continued to lose their vision. Moreover, these drugs had numerous visual and systemic side effects such as low blood pressure, confusion, or anorexia which may be especially serious for older adults. Lastly, the use of glaucoma medications required strict compliance and the regime of multiple medications and side effects were often problematic.

Fortunately, laser treatment has become the primary approach to treatment. The National Eye Institute has found that early use of laser surgery is at least as effective and has fewer side effects than the long-term use of eye drops. Argon laser trabeculoplasty (ALT) relieves pressure by creating drainage holes in the eye's filtering area.

Prevention

The best way to detect glaucoma is to see an eye specialist who uses a combination of tonometry (e.g., air puff test) and direct opthalmoscopy through dilated pupils. Tonometry is a screening test used to check intraocular pressure (IOP) and detect glaucoma. High risk adults should have a complete visual exam with dilation of the eye every 1 to 2 years, and all adults over age 40 should have a screening examination every 3 years to check for cupping of the optic nerve evacuation and a visual field exam to identify any visual field defects.