Visionrehab

Definition
Glaucoma is a group of eye diseases that slowly steals sight - typically without symptoms. Vision impairment from glaucoma is caused by damage to the optic nerve. The nerve is similar to an electric cable by carrying the images we see in the eye to the brain via electrical impulses. Although intra-ocular pressure (IOP) is clearly a risk factor, we now know that even people with "normal" IOP can experience vision loss from glaucoma.

Causes
There are several primary categories of glaucoma. The most common form, primary open angle glaucoma (POAG) is when the main drainage area inside the eye is open and clear for maximum drainage, however the eye pressure remains high. In angle closure glaucoma, also called acute glaucoma, this main drainage area becomes blocked and the pressure can rise to very high levels. Secondary glaucoma results from some other factors such as medications, trauma or infection. Normal tension glaucoma is diagnosed when the optic nerve is damaged even though the pressures are found to stay within the normal range (normally between 12 and 22 mm Hg).

Individuals most at risk of acquiring glaucoma include African Americans, those over 60 years of age, those with a family history, and those who have had trauma directly to the eye.

Effect on Vision
The elevated pressure inside the eye causes damage to the nerve fibers in the retina and the optic nerve. There is no pain associated in most forms of glaucoma. As the damage progresses, bits and pieces of vision are blanked out, creating what is called scotomas. If left untreated, glaucoma can lead to total blindness.

Treatments
Glaucoma can be treated with eye drops, pills, laser surgery, eye operations, or a combination of these methods. The goal of treatment is to prevent further loss of vision since any loss is irreversible.