What is it?
Glaucoma is a very complex group of eye disease that can lead to permanent loss of vision. It is the second leading cause of blindness in the world; in African Americans, it is the number one cause of blindness. It is estimated that, in the United States, over 2.2 million people have glaucoma but only half are aware that they have it. This is largely due to the fact that the most common type of glaucoma has very few symptoms before vision loss occurs; there is no pain, no redness, no swelling. For this reason, patients need to be aware of their potential risk for glaucoma and have regular eye examinations.
Simply put, glaucoma is defined as damage to the optic nerve as a result of elevated intraocular pressure. Damage to the optic nerve causes vision loss that starts in the periphery (side) of your vision. Unfortunately, there is no cure for glaucoma but, through early diagnosis and appropriate treatment, useful vision can often be preserved.
Types of Glaucoma
Primary open-angle glaucoma: This is the most common type of glaucoma. It usually develops slowly and insidiously. There are no early warning signs or symptoms. In primary open-angle glaucoma, the entrance to the drainage canals in the eye appears to be open; however, there is a problem with drainage further down the drainage system, which causes an increase in the pressure inside the eye. This increased pressure damages the optic nerve. Primary open-angle glaucoma usually responds to proper treatment with medication (usually eye drops), especially if it is caught early.
Angle-closure glaucoma: In this type of glaucoma, the drainage canals are blocked, usually by the iris (colored part of the eye), which is abnormally bunched up near the drainage canals. If the iris completely blocks the drainage system, the eye pressure can skyrocket to a very dangerous level quickly, causing permanent damage to the optic nerve. If your eye appears to be at risk for angle-closure glaucoma, our doctors may recommend that you undergo a preventative laser procedure that makes a small hole in the outer part of your iris. This opening helps open the drainage canal so the pressure will not become elevated.
Normal-tension glaucoma: This type of glaucoma is a bit of a mystery. In normal-tension glaucoma, the eye pressure is not elevated and, yet, the optic nerve still suffers damage. No one is quite sure why this happens, but we do know that certain people are at higher risk: people with a family history of normal-tension glaucoma, people with Japanese ancestry, and people with a history of systemic heart disease (such as an irregular heartbeat).
Secondary glaucoma: This term refers to any situation in which another disease process causes or contributes to elevated eye pressure. Examples include: prior eye injury or trauma, diabetes, steroids, inflammation, advanced cataracts. Secondary glaucoma is treated based on whether it is determined to be open-angle or angle-closure glaucoma.
Congenital glaucoma (childhood glaucoma): As the name implies, this type of glaucoma is diagnosed in infancy or early childhood. It occurs in about 1 in 10,000 births in the United States. Congenital glaucoma may be caused by a hereditary genetic defect or abnormal development of the eye during pregnancy. It is treated most often by microsurgery and medications.
Who is at risk?
African Americans: Glaucoma is 6-8 times more common in African Americans than Caucasians.
Hispanics: Recent studies are showing glaucoma may be the leading cause of blindness in Hispanics as well as African Americans.
People over 60: You are 6 times more likely to get glaucoma if you are over 60 years of age.
People with a family history of glaucoma: Family history increases your risk by 4-9 times.
Asian ancestry: People of Asian descent appear to be at higher risk for angle-closure glaucoma.
Steroid users: There is some evidence linking steroid use to glaucoma. This can be either very large doses of systemic steroids or steroid eye drops.
People with prior eye injury: Glaucoma can occur immediately after the injury or years later.
The goal of glaucoma treatment is to lower the eye pressure to a level that no longer damages the optic nerve. Initially, prescription drops are used, and these medications work very well in patients who take them consistently. In some cases, laser treatment may be used as a supplemental therapy. In patients whose eye pressures do not respond adequately to medications, surgery may be recommended.