Open Angle Glaucoma

A Common Eye Condition

Glaucoma is an eye condition which currently affects 7 to 8 million Americans. There are actually twenty different types of glaucoma, many of which fall under the broad category known as 'open angle'.

Open angle glaucoma is a painless, progressive disease that results in irreversible damage to the optic nerve. Individual ganglion cells that comprise the optic nerve are responsible for transmission of information from the retina to the brain. In eyes affected by open angle glaucoma, these ganglion cells die, resulting in a permanent loss of sight. The destruction of the cells is usually preceded by an increase in eye pressure (intraocular pressure). The cause of the pressure rise is not currently understood. Many research projects are currently underway to answer this very important question.

Normal Optic Nerve
Photo of normal optic nerve

There are no symptoms in the early stages of open angle glaucoma. The eye does not become red or painful. An eye examination is the only way to detect glaucoma. The doctor measures the 'intraocular pressure', examines the optic nerve and may have the patient perform a visual field test. When a patient is aware of vision loss as a result of untreated glaucoma, irreversible damage may have already occurred.

One form of open angle glaucoma, diagnosed at birth or shortly after, is called 'congenital'. When diagnosed in patients during their teens or early twenties, open angle glaucoma is referred to as juvenile onset. There is also a form which is often first diagnosed in middle aged and older patients and is known as primary open angle glaucoma. It is currently unknown how much genetic overlap there may be between these three categories, if any. We are also investigating two syndromes which place individuals at increased risk for developing glaucoma: pigmentary dispersion syndrome and pseudoexfoliation. Pigmentary dispersion syndrome and pigmentary glaucoma are usually diagnosed in young adulthood. Pseudoexfoliation is most usually diagnosed in middle aged or older patients.

Fortunately, many medicines and surgical treatments are currently widely available to treat open angle glaucoma. It is important to stress that the earlier treatment is initiated, the less vision loss is likely to occur. If left untreated, glaucoma can lead to total blindness.