Glaucoma....

What is Glaucoma?


Glaucoma is a group of eye diseases that gradually steal sight without warning. In the early stages of the disease, there may be no symptoms. Experts estimate that half of the people affected by glaucoma may not know they have it.

Vision loss is caused by damage to the optic nerve. This nerve acts like an electric cable with over a million wires. It is responsible for carrying images from the eye to the brain.

There is no cure for glaucoma—yet. However, medication or surgery can slow or prevent further vision loss. The appropriate treatment depends upon the type of glaucoma among other factors. Early detection is vital to stopping the progress of the disease.

It was once thought that high pressure within the eye, also known as intraocular pressure or IOP, is the main cause of this optic nerve damage. Although IOP is clearly a risk factor, we now know that other factors must also be involved because even people with “normal” levels of pressure can experience vision loss from glaucoma.

Adult glaucoma falls into two categories—open angle glaucoma and closed angle glaucoma.

Types of Glaucoma

The two main types of glaucoma are primary open angle glaucoma (POAG), and angle closure glaucoma. These are marked by an increase of intraocular pressure (IOP), or pressure inside the eye. When optic nerve damage has occurred despite a normal IOP, this is called normal tension glaucoma. Secondary glaucoma refers to any case in which another disease causes or contributes to increased eye pressure, resulting in optic nerve damage and vision loss.

How common is glaucoma?

Worldwide, glaucoma is the leading cause of irreversible blindness. In fact, as many as 6 million individuals are blind in both eyes from this disease. In the United States alone, according to one estimate, over 3 million people have glaucoma. As many as half of the individuals with glaucoma, however, may not know that they have the disease. The reason they are unaware is that glaucoma initially causes no symptoms, and the loss of vision on the side (periphery) is hardly noticeable.

What are the risk factors for glaucoma?

• Age over 45 years

• Family history of glaucoma

• Black racial ancestry

• Diabetes

• History of elevated intraocular pressure

• Nearsightedness (high degree of myopia), which is the inability to see distant objects clearly

• History of injury to the eye

• Use of cortisone (steroids), either in the eye or systemically (orally or injected)

• Farsightedness (hyperopia), which is seeing distant objects better than close ones (Farsighted people may have narrow filtering angles, which predispose them to acute (sudden) attacks of closed-angle glaucoma