What is glaucoma?
Glaucoma is frequently called the “sneak thief of sight,” because there are often no symptoms before severe vision loss occurs. This is the leading cause of blindness in the United Stated. An estimated 1 out of 50 adults is affected with this disease. Loss of sight from glaucoma is preventable with early detection and treatment by your optometrist or ophthalmologist. Glaucoma is a series of diseases of the optic nerve. The optic nerve is the messenger between the the eyes and the brain, when it becomes damaged, vision is impaired.
What causes glaucoma?
Glaucoma is caused by pressure in the eye caused by a build up of a fluid, called the aqueous humor. The aqueous humor circulates through the eye, nourishing the tissues, and then exits the eye through a drainage system called the angle. When this drainage system becomes obstructed, fluid builds up, causing the pressure inside the eye to rise. In some cases, the eye simply produces more aqueous humor than it can drain, which also results in a rise of pressure. This elevated pressure cannot be felt, there are no symptoms or side-effects until damage has already been done to the optic nerve.
What are the different types of glaucoma?
- Chronic open-angle glaucoma is the most common type of glaucoma. In this type of glaucoma, the drainage angle is open, but working less efficiently, usually due to age. As a result, pressure builds up slowly, causing a gradual loss of side vision which progresses so slowly it usually goes undetected.
- Angle-closure glaucoma occurs when the drainage angle of the eye is totally blocked, preventing any fluid to drain. This causes the pressure inside the eye to rise suddenly. This instant rise in pressure can cause halos to appear around lights, blurred vision, headaches and severe eye pain. Call your ophthalmologist or optometrist immediately, if your are experiencing any of these symptoms. Your vision may be in eminent danger.
- Chronic angle-closure glaucoma is a more gradual and painless closing of the angle. Chronic angle-closure glaucoma occurs more frequently in people of African and Asian ancestry.
- Secondary glaucoma happens when scar tissue blocks the drainage angle as a result of injury, infection or drug use. Loss of side-vision is the first symptom. Secondary glaucoma progresses much like chronic open-angle glaucoma. Congenital glaucoma is a birth defect affecting the drainage angle. Symptoms include augmented eyes, a cloudy cornea, sensitivity to light and excessive tearing. In order to prevent blindness, this condition must be treated soon after birth.
How is glaucoma detected?
Glaucoma is most often found during a dilated eye examination, which is utterly painless. During an examination, your eye doctor will measure the intraocular pressure of your eye, inspect the drainage angle, evaluate any damage to the optic nerve and test the vision of each eye.It may not be necessary for you to have all of these tests, although it is recommended that you repeat them on a regular basis to determine if optic nerve damage is increasing over time.
Glaucoma is usually treated in office with prescription eye drops and by laser procedures known as Argon Laser Trabeculectomy (ALT) or Selective Laser Trabeculectomy (SLT).
Who is at risk for glaucoma?
Anyone can get glaucoma, however some people are at a higher risk. They include:
- African-Americans over age 40
- Anyone over 60
- People with a family history of glaucoma
- People with a history of severe anemia or shock
- People with past injuries to the eyes
- People with myopia
Remember, prevention is painless, but sight loss is devastating.