Open Angle Glaucoma

A Common Eye Condition

There are more than 20 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 thought to be caused by an increase in eye pressure (intraocular pressure). The cause of this sensitivity is not currently understood. Many research projects are currently underway to answer this very important question.

Normal Optic Nerve
Photo of normal optic nerve

 

Symptoms:There are no symptoms in the early stages of open angle glaucoma. The eye does not become red or painful. When a patient becomes aware of vision loss as a result of untreated glaucoma, irreversible damage has likely already occurred.

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.

 

Types of Open Angle Glaucoma:

  • Congenital glaucoma:  One form of open angle glaucoma, diagnosed at birth or shortly after, is called 'congenital'.
  • Juvenile onset:  When diagnosed in patients during their teens or early twenties, open angle glaucoma is referred to as juvenile onset.
  • Primary open angle glaucoma:  A form which is often first diagnosed in middle aged and older patients.

Other Syndromes:  There are many open angle glaucomas associated with medical syndromes.  These are called secondary glaucomas.  Two of the more common syndromes are:

  • Pigmentary dispersion syndrome and pigmentary glaucoma, which  are usually diagnosed in young adulthood.
  • Pseudoexfoliation, which is most usually diagnosed in middle aged or older patients.   Patients with this condition secrete protein within the fluid of the inner eyeball. The protein then forms a layer on some of the internal structures of the eye, and can partially block normal drainage.

Treatment:
Fortunately, many medicines and surgical treatments are 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.