Glaucoma Health Article

Definition

Glaucoma is a group of eye disorders that results in vision loss due to a failure to maintain the normal fluid balance within the eye. If fluid pressure builds up, then damage to the optic nerve occurs, leading to vision loss. If detected in its early stages, vision loss can be prevented through the use of medications or surgical procedures that restore the proper fluid drainage of the eye.

Description

Vision is an important and complex special sense by which the qualities of an object, such as color, shape, and size, are perceived through the detection of light. Light that bounces off an object first passes through the cornea (outer layer) of the eye and then through the pupil and the lens to project onto a layer of cells on the back of the eye called the retina. When the retina is stimulated by light, signals pass through the optic nerve to the brain, resulting in a visual image of an object.

The front chamber of the eye is bathed in a liquid called the aqueous humor. This liquid is produced by a nearby structure called the ciliary body and is moved out of the eye into the bloodstream by a system of drainage canals known as the trabecular meshwork. The proper amount of fluid within the chamber is maintained by a balance between fluid production by the ciliary body and fluid drainage through the trabecular meshwork. When fluid accumulates in the front chamber, either because of an overproduction of fluid or because of a failure of the normal drainage routes, fluid pressure builds up within the eye. Over time, this increased fluid pressure causes damage to the optic nerve, resulting in progressive visual impairment. The condition of increased eye fluid pressure leading to vision loss is known as glaucoma.

Glaucoma is actually a group of many different eye disorders and can manifest alone or as a sign of more than 60 different diseases, or even in a healthy person who has experienced an injury to the eye. Physicians classify glaucoma by the type of abnormality in the drainage system. When the drainage passage is narrowed, but still open, it is termed open-angle glaucoma. If the drainage passage is completely blocked, it is termed closed-angle glaucoma. Glaucoma can also be classified by the age of the affected individual: infantile or congenital glaucoma affects infants at birth or children up to three years old, juvenile glaucoma affects individuals from 3–30 years old, and adult glaucoma affects people greater than 30 years old.