What is Glaucoma?

A diagnosis of glaucoma means that one's intraocular pressure (the pressure within the eye) is at a level higher than the optic nerve fibers can tolerate. This elevated pressure causes damage to the nerve fibers of the optic nerve. This damage results in a loss of peripheral vision (side vision). This visual loss can be so gradual that patients are not aware of what is happening until only their central vision remains. This central "gun barrel" vision is very difficult to use because the visual target sought by the patient can be extremely hard to locate in a "sea of darkness". This type of vision can be simulated by rolling up a piece of paper and looking through one end to see the surrounding world.

There are several types of glaucoma and the types are generally classified by the cause of the elevated intraocular pressure. In general, the glaucomas can be divided into two groups: those with an acute onset of elevated pressure causing blurred vision and pain, and those with a gradual increase in intraocular pressure with no immediate perceived change in visual function or discomfort.

Regular examinations will usually reveal both of these types of glaucoma during their early stages. The potential to develop acute glaucoma can be alleviated by the use of laser treatment. After the acute attack occurs treatment is more difficult and a combination of medicines, laser surgery and possibly incisional surgery can be required. No visual loss occurs when the patient is treated prior to the actual acute attack. When treatment follows the acute attack, permanent visual loss can occur to some degree and continued medical treatment throughout the patient's life is usually needed.

Chronic glaucoma usually takes many years to rob the patient of vision and can often be treated successfully with topical medication when the disease is discovered in a timely fashion. Many useful drugs to treat this condition are presently available and new drugs are continually being introduced. Occasionally laser and/or incisional surgery is necessary to preserve vision. However, this decision is made over a period of time unlike the immediate decision often required to treat potential acute glaucoma.

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