Glaucoma is a group of eye diseases that gradually steals sight without warning and often without symptoms. Vision loss is caused by damage to the optic nerve. This nerve acts like an electric cable with over a million wires and is responsible for carrying the images we see to the brain.
The Importance of the Optic Nerve (from Sept.2004 Gleams)
Optic Cupping (from Winter 1999 Gleams)

It was once thought that high intraocular pressure (IOP) was 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" IOP can experience vision loss from glaucoma.


Different Types of Glaucoma

The two main types of glaucoma are open angle glaucoma, or primary open angle glaucoma (POAG), and angle closure glaucoma.

Primary Open Angle Glaucoma
Angle Closure Glaucoma

Normal Tension Glaucoma (NTG)

Secondary Glaucoma
Pigmentary Glaucoma
Traumatic Glaucoma
Pseudoexfoliative Glaucoma
Neovascular Glaucoma
Irido Corneal Endothelial Syndrome (ICE)


Cataracts and Glaucoma


Primary Open Angle Glaucoma


Most people have no symptoms and no early warning signs. If open angle glaucoma is not diagnosed and treated, it can cause a gradual loss of vision. This type of glaucoma develops slowly and sometimes without noticeable sight loss for many years. It usually responds well to medication, especially if caught early and treated.

Angle Closure Glaucoma
This type of glaucoma is also known as acute glaucoma or narrow angle glaucoma. It is much more rare and is very different from open angle glaucoma in that the eye pressure usually goes up very fast. This happens when the drainage canals get blocked or covered over, like the clog in a sink when something is covering the drain. With angle closure glaucoma, the iris and cornea is not as wide and open as it should be. The outer edge of the iris bunches up over the drainage canals, when the pupil enlarges too much or too quickly. This can happen when entering a dark room.

A simple test can be used to see if your angle is normal and wide or abnormal and narrow. Treatment of angle closure glaucoma usually involves surgery to remove a small portion of the outer edge of the iris. This helps unblock the drainage canals so that the extra fluid can drain. Usually surgery is successful and long lasting. However, you should still receive regular check-ups. Symptoms of angle closure glaucoma may include headaches, eye pain, nausea, rainbows around lights at night, and very blurred vision.

Normal Tension Glaucoma (NTG)


Those at higher risk for this form of glaucoma are people with a family history of normal tension glaucoma, people of Japanese ancestry, and people with a history of systemic heart disease, such as irregular heart rhythm. Normal tension glaucoma is usually detected after an examination of the optic nerve.

The Glaucoma Research Foundation sponsored an international study to help determine the best treatment for this type of glaucoma (Collaborative NTG Study). The study concluded eye drops that lower IOP were effective even in cases of normal tension glaucoma. Currently, most doctors treat normal tension glaucoma by keeping normal eye pressures as low as possible with medicines, laser surgery, or filtering surgery.

Secondary Glaucoma
Glaucoma can occur as the result of an eye injury, inflammation, tumor or in advanced cases of cataract or diabetes. It can also be caused by certain drugs such as steroids. This form of glaucoma may be mild or severe. The type of treatment will depend on whether it is open angle or angle closure glaucoma.

Pigmentary Glaucoma
This is a form of secondary open angle glaucoma. It occurs when the pigment granules in the back of the iris (the colored part of the eye) break into the clear fluid produced inside the eye. These tiny pigment granules flow toward the drainage canals in the eye and slowly clog them, causing eye pressure to rise. Treatment usually includes medications or surgery. Go to Gleams Article

Traumatic Glaucoma


Pseudoexfoliative Glaucoma
This is a form of secondary open angle glaucoma. It occurs when a flaky, dandruff-like material peels off the outer layer of the lens within the eye. The material collects in the angle between the cornea and iris and can clog the drainage system of the eye, causing eye pressure to rise. Long recognized as common in those of Scandinavian descent. Treatment usually includes medications or surgery.

Neovascular Glaucoma


Irido Corneal Endothelial Syndrome (ICE)


ICE occurs more frequently in light-skinned females. Symptoms can include hazy vision upon awakening and the appearance of halos around lights. ICE is difficult to treat and laser therapy is not an effective therapy. ICE is usually treated with medications and/or filtering surgery.

Cataracts and Glaucoma


Both cataracts and glaucoma are serious conditions that can cause you to lose vision. However, loss of vision due to cataracts can be reversed with surgery. Loss of vision from glaucoma is, as yet, irreversible.