Glaucoma belongs to a group of eye diseases often caused by increased eye pressure. Unless the pressure is controlled, it can cause damage to the optic nerve and loss of vision. In its early stages, glaucoma is difficult to diagnose; it is virtually symptom-free. 

As the condition progresses, side vision may begin to fade. 

If left untreated, the visual field will continue to narrow and blindness will result. Glaucoma is the leading cause of blindness in the United States. Nearly three million people have some form of it. Fortunately, if detected early, glaucoma can usually be controlled.


Over the past century, increased intraocular pressure [IOP = pressure formed in the microcirculation of fluid in the eye] has been the most important marker for the diagnosis of glaucoma.

Eyes can have an IOP within the normal range and still develop glaucoma. On the other hand, increased IOP can be present without detectable damage to the optic nerve, called ocular hypertension. So the new thinking is that progressive retinal damage may not directly correlate with the magnitude of the IOP level. The best way to protect oneself is to be aware of the risk and make sure one has regular comprehensive screening.

People at higher risk are those with a family history of glaucoma, black Americans over 40, anyone with elevated eye pressure, anyone over 60 (the older you are, the more at risk you are). People at higher risk for glaucoma could have their eyes examined every two years for dilated pupils. Advanced diagnostic tests are used to diagnose and manage glaucoma. All patients will undergo visual field examinations using both automated and manual tests, ophthalmic photography (photographs of the optic nerve) and nerve fiber layer photography with a digital system. Delayed intervention is likely to result in more permanent and greater vision loss. Thus, early control would be the best strategy for anyone with elevated intraocular pressure or early glaucoma.

There are many types of glaucoma: primary open angle (which accounts for about 80% of all cases), normal tension, narrow angle, acute angle closure, chronic angle closure, childhood, congenital (infantile), juvenile, after cataract extraction (cataract surgery), pigment dispersion(PDS is a chronic eye disease in which the filter at the iris becomes blocked by pigment particles) and pseudoexfoliation (form of chamber angle glaucoma)of uveitis(inflammation of the inside of the eye) and glaucoma after trauma (traumatic).


For reasons doctors do not fully understand, increased pressure in the eye (intraocular pressure) is usually, but not always, associated with the optic nerve damage that characterizes glaucoma. This pressure is due to a buildup of a fluid (aqueous humor) that flows in and out of your eye. This fluid normally leaves the eye through a drainage system at the corner where the iris meets the cornea. When the drainage system is not working properly, the fluid cannot filter out of the eye at its normal rate and the pressure in the eye increases.


In primary open-angle glaucoma, the drainage angle formed by the cornea and iris remains open, but the drainage channels (trabecular meshwork) in the angle are partially blocked, causing fluid to drain out of the eye too slowly. This causes fluid to enter your eye and the pressure in your eye gradually increases. Damage to the optic nerve causes no symptoms or pain, and it happens so slowly that you can lose an extensive amount of vision before even being aware of a problem. The exact cause of primary open-angle glaucoma remains unknown.


Angle closure glaucoma, also called closed-angle glaucoma, occurs when the iris bulges forward, narrowing or blocking the drainage angle formed by the cornea and iris. As a result, fluid cannot flow adequately through and out of your eye, and your eye pressure may increase abruptly. Angle-closure glaucoma usually occurs suddenly (acute angle-closure glaucoma), but it can also occur gradually (chronic angle-closure glaucoma).

Some people with an abnormally narrow drainage angle are at risk of developing angle-closure glaucoma.

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