Open-angle glaucoma; Chronic glaucoma; Closed-angle glaucoma; Congenital glaucoma; Angle closure glaucoma
Glaucoma refers to a group of eye conditions that lead to damage to the optic nerve, the nerve that carries visual information from the eye to the brain.
In many cases, damage to the optic nerve is due to increased pressure in the eye, also known as intraocular pressure (IOP).
Glaucoma is the second most common cause of blindness in the United States. There are four major types of glaucoma:
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.
Open-angle (chronic) glaucoma is the most common type of glaucoma.
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).
Secondary glaucoma is caused by:
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Vass C, Hirn C, Sycha T, Findl O, Bauer P, Schmetterer L. Medical interventions for primary open angle glaucoma and ocular hypertension. Cochrane Database Syst Rev. 2007 Oct 17;(4):CD003167.
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