Glaucoma is a group of eye diseases that involve a gradual build of aqueous humor, a fluid that is naturally and continuously produced in the front part of the eye, causing increased eye pressure (intraocular pressure). Aqueous humor exists in the eye through a drainage system at the angle where the iris and cornea meet. If the drainage system does not work properly, aqueous humor can’t filter out of the eye the normal rate and pressure builds up in the eye. If untreated, it can result in optic nerve damage and blindness. It is sometimes called the “silent thief of sight” because there are often no noticeable symptoms until the advanced stages of the disease. Damage to the optic nerve is painless and the loss of vision is so gradual that it may not be noticed until a large portion of vision is already lost. There are several types of glaucoma:

Primary open-angle glaucoma: most common type; also called wide-angle glaucoma; cause unknown; drainage angle at the cornea and iris remains open, but the some of the microscopic drainage channels (trabecular meshwork) are blocked; the aqueous humor drains too slowly causing fluid build up and increased eye pressure

Angle-closure glaucoma: occurs when the iris bulges forward, narrowing (narrow-angle glaucoma) or closing the angle formed by the cornea and the iris keeping the aqueous humor from draining properly or at all; can occur abruptly (acute angle-closure) or gradually (chronic angle-closure)

Low-tension glaucoma: poorly understood, but not uncommon; optic nerve damage occurs even though eye pressure stays within normal range; some experts believe that it could be related to an overly sensitive optic nerve or reduced blood supply to the optic nerve due to atherosclerosis

Congenital glaucoma: some children are born with a defect in the angle of the eye that causes slow drainage of the aqueous humor and in turn a build up of fluid and increased eye pressure; usually the children have obvious symptoms: cloudy eyes, sensitivity to light, excessive tearing; with the recommended surgery, these children have a good chance of having normal vision

Secondary glaucomas: can develop as complication with other medical condition (i.e. advanced cataracts, eye injury, tumors, uveitis); pigmentary glaucoma is caused by pigment from the iris flaking off and blocking the trabecular meshwork, causing slowed fluid drainage; neovascular glaucoma is linked to diabetes

Unfortunately, glaucoma cannot be completely cured. However, treatment can prevent further vision loss. There are treatment options which include medicated eye drops, laser surgery or microsurgery. The goal of treatment is to reduce intraocular pressure by improving the flow of aqueous humor, reducing the production of aqueous humor or both.


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