Primary Open-Angle Glaucoma

This is the most common form of glaucoma, affecting about three million Americans. It happens when the eye’s drainage canals become clogged over time. The inner eye pressure (also called intraocular pressure or IOP) rises because the correct amount of fluid can’t drain out of the eye. With open-angle glaucoma, the entrances to the drainage canals are clear and should be working correctly. The clogging problem occurs further inside the drainage canals, similar to a clogged pipe below the drain in a sink.

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 rarer and is very different from open-angle glaucoma in that the eye pressure usually rises very quickly.

This happens when the drainage canals get blocked or covered over, like a sink with something covering the drain.

With angle-closure glaucoma, the iris 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 place where fluid drains. This helps unblock the drainage canals so that the extra fluid can drain. Usually, Dr. Carter's surgery is largely successful and long lasting. However, you should still receive regular check-ups with us.

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.

Pseudoexfoliative Glaucoma

This form of secondary open-angle glaucoma 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. Pseudoexfoliative Glaucoma is common in those of Scandinavian descent. Treatment usually includes medications or surgery.

Pigmentary Glaucoma

A form of secondary open-angle glaucoma, this 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.

Traumatic Glaucoma

Injury to the eye may cause secondary open-angle glaucoma. This type of glaucoma can occur immediately after the injury or years later. It can be caused by blunt injuries that “bruise” the eye (called blunt trauma) or by injuries that penetrate the eye. In addition, conditions such as severe nearsightedness, previous injury, infection, or prior surgery may make the eye more vulnerable to a serious eye injury.

Neovascular Glaucoma

The abnormal formation of new blood vessels on the iris and over the eye’s drainage channels can cause a form of secondary open-angle glaucoma.

Neovascular glaucoma is always associated with other abnormalities, most often diabetes. It never occurs on its own. The new blood vessels block the eye’s fluid from exiting through the trabecular meshwork (the eye’s drainage canals), causing an increase in eye pressure. This type of glaucoma is very difficult to treat.

Normal Tension Glaucoma (NTG)

Normal tension glaucoma is also known as low-tension glaucoma or normal pressure glaucoma. In this type of glaucoma, the optic nerve is damaged even though intraocular pressure (IOP) is not very high. Doctors do not know why some people’s optic nerves suffer damage even though pressure levels are in the “normal” range (between 12-22 mm Hg).

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 a collaborative international study to help determine the best treatment for this type of glaucoma. The study concluded that eye drops used to lower intraocular pressure 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.

Pediatric Glaucoma

The pediatric glaucomas consist of congenital glaucoma (present at birth), infantile glaucoma (appears during the first three years), juvenile glaucoma (age three through the teenage or young adult years), and all the secondary glaucomas occurring in the pediatric age group. Congenital glaucoma is present at birth and most cases are diagnosed during the first year of life. Sometimes symptoms are not recognized until later in infancy or early childhood.

The range of treatment is very different from that for adult glaucoma. It is very important to catch pediatric glaucoma early in order to prevent blindness.

Treatment

Medications are usually sufficient to treat most cases of glaucoma. Sometimes a laser or even surgery may be necessary. Lasers can include an SLT to the trabecular meshwork to help facilitate drainage or an Peripherial Iridotomy which shoots a hole in the iris to provide an alternative to the pupil for shunting fluid. This is helpful to prevent attacks of angle-closure glaucoma in patients with narrow angles.