Types of Glaucoma
Glaucoma is the second most common cause of blindness in the United States. There are four major types of glaucoma:
- Open-angle (chronic) glaucoma the cause is unknown. An increase in eye pressure occurs slowly over time. The pressure pushes on the optic nerve and the retina at the back of the eye.
- Angle-closure (acute) glaucoma occurs when the exit of the aqueous humor fluid is suddenly blocked. This causes a quick, severe, and painful rise in the pressure within the eye (intraocular pressure).
- Congenital glaucoma often runs in families (is hereditary). It is present at birth, and It results from the abnormal development of the fluid outflow channels in the eye.
- Secondary glaucoma is caused by: Drugs such as corticosteroids, Eye diseases such as uveitis, Systemic diseases.
The front part of the eye is filled with a clear fluid called aqueous humor. This fluid is always being made in the back of the eye. It leaves the eye through channels in the front of the eye in an area called the anterior chamber angle, or simply the angle. Anything that slows or blocks the flow of this fluid out of the eye will cause pressure to build up in the eye. This pressure is called intraocular pressure (IOP). In most cases of glaucoma, this pressure is high and causes damage to the major nerve in the eye, called the optic nerve.