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Glaucoma is an eye condition that develops when too much fluid pressure builds up inside of the eye.

The increased pressure, called intraocular pressure, can damage the optic nerve, which transmits images to the brain. If damage to the optic nerve from high eye pressure continues, glaucoma will worsen your vision. Without treatment, glaucoma can cause blindness within a few years.

Because most people with glaucoma have no early symptoms or pain from this increased pressure, it is important to see your eye care doctor regularly so that glaucoma can be diagnosed and treated before long-term visual loss occurs.

If you are over the age of 45 and if you have a family history of glaucoma, you should have a complete eye exam with an ophthalmologist every one to two years. If you have health problems such as diabetes or a family history of glaucoma or are at risk for other eye diseases, you may need to visit your eye doctor more frequently.

Why Does Pressure Rise in the Eye to Cause Glaucoma?

Glaucoma usually occurs when intraocular pressure increases. This happens when the fluid pressure in the eye's anterior chamber, the area between the cornea and the iris, rises.

Normally, this fluid, called aqueous humor, flows out of the eye through a mesh-like channel. If this channel becomes blocked, fluid builds up causing glaucoma. The direct cause of this blockage is unknown, but doctors do know that it is most often inherited, meaning it is passed from parents to children.

Less common causes of glaucoma include a blunt or chemical injury to the eye, severe eye infection, blockage of blood vessels in the eye, inflammatory conditions of the eye, and occasionally eye surgery to correct another condition. Glaucoma usually occurs in both eyes, but it may involve each eye to a different extent.

What Are the Types of Glaucoma?

There are two main types of glaucoma:

1. . Open-angle glaucoma. Also called wide-angle glaucoma, this is the most common type of glaucoma. The structures of the eye appear normal, but fluid in the eye does not flow properly through the drain of the eye, called the trabecular meshwork.
2. . Angle-closure glaucoma. Also called acute or chronic closed-angle or narrow-angle glaucoma, this type of glaucoma is less common, but can cause a sudden buildup of pressure in the eye. Drainage may be poor because the angle between the iris and the cornea (where a drainage channel for the eye is located) is too narrow. Or, the pupil opens too wide, narrowing the angle and blocking the flow of the fluid through that channel.

Who Gets Glaucoma?

Glaucoma most often occurs in adults over age 40, but it can also occur in young adults, children, and even infants. In African Americans, glaucoma occurs at an earlier age and with greater loss of vision.

You are at an increased risk of glaucoma if you:

• Are of African-American, Irish, Russian, Japanese, Hispanic, Inuit, or Scandinavian descent
• Are over age 40
• Have a family history of glaucoma
• Have poor vision
• Have diabetes
• Take corticosteroid medications, such as prednisone

What Are the Symptoms of Glaucoma?

For most people, there are usually few or no symptoms of glaucoma. The first sign of glaucoma is often the loss of peripheral or side vision, which can go unnoticed until late in the disease. Detecting glaucoma early is one reason you should have a complete exam with an eye specialist every one to two years. Occasionally, intraocular pressure can rise to severe levels. In these cases, sudden eye pain, headache, blurred vision, or the appearance of halos around lights may occur.

If you have any of the following symptoms, seek immediate medical care:

• Seeing halos around lights
• Narrowing of vision (tunnel vision)
• Vision loss
• Redness in the eye
• Eye that looks hazy
• Nausea or vomiting
• Pain in the eye