What is glaucoma?

Glaucoma is a disease of the optic nerve, which carries images from the eye to the brain.  The optic nerve is made up of bundles of nerve fibers, similar to an electric cable that contains many wires.  When these fibers are damaged, they create blind spots that gradually get more significant over time. 

What causes glaucoma?

Glaucoma is caused by a build up of too much pressure in the clear liquid that circulates inside the front part of your eye. This liquid is called the aqueous humor.  A small amount of fluid is produced constantly while an equal amount flows out of the eye through a tiny drainage system.  When the drainage area - called the drainage angle - is blocked, too much fluid builds up, pushes against the optic nerve, and causes damage.

What are the different types of glaucoma?

1.Chronic Open-Angle

The most common type of glaucoma in this country is called Chronic Open-Angle Glaucoma. This happens when the drainage angle of the eye gradually becomes less efficient as you age, leading to growing pressure and gradual optic nerve damage.  In the early stages, you likely have no symptoms.  As the optic nerve becomes more damaged, you may see blank spots in your field of vision, which gradually affects your daily activities.

2. Closed-Angle

This less common type of glaucoma is caused by the iris (the colored part of the eye) being formed too close to the drainage angle. You may not know you have this type of glaucoma until you get an attack that may include blurred vision, severe eye pain, headache, rainbow-colored halos around lights, and/or nausea and vomiting. You should immediately call your eye doctor or go to an emergency room.

Who is at risk?

The following factors increase your risk of getting glaucoma:

• Increasing age
• Elevated eye pressure
• Family history of glaucoma
• African or Spanish ancestry
• Being farsighted or nearsighted
• Past eye injuries
• Systemic health problems such as diabetes

If you are at risk for developing glaucoma, you should get regular examinations by your eye doctor.

How is glaucoma detected?

Regular testing will help to detect glaucoma at an early stage.  Recommended exam schedules are:

Ages 20 - 29 - those at high risk should be tested every 3-5 years; others should be tested once

Ages 30 -39 - high risk patients should get testing every 2-4 years; others should have two eye exams

Ages 40 - 64 - everyone should be tested every 2-4 years

Age 65 and older - get tested every 1 -2 years

A complete exam to detect glaucoma involves the following:

• Tonometry - a test to measure your eye pressure
• Gonioscopy - an inspection of the drainage angle
• Ophthalmoscopy - evaluating for optic nerve damage
• Visual field test - testing your peripheral vision

How is glaucoma treated?

Eyedrops, oral medication, laser surgery and surgery in an operating room are treatments that may be used to prevent further damage of the optic nerve.  Your doctor cannot usually reverse damage that has already taken place.  That makes early and periodic exams for those at risk critical.

Glaucoma eye drops need to be taken daily to lower your eye pressure.  Never stop taking medication without the advice of your ophthalmologist.  Let him know if you have any side effects and make sure that you inform him of other medications you take to prevent adverse interaction.

Laser surgery can involve a trabeculoplasty to change the drainage angle in open-angle glaucoma.  A iridotomy is a laser procedure that creates a hole in the iris to improve drainage for patients with closed angle glaucoma.