Understanding Glaucoma Can Save Your Sight

    SEATTLE, WA, December 12, 2009 /24-7PressRelease/ -- Glaucoma is a disease that affects the optic nerve, the nerve which carries image information from the eyes to the brain. It enters the eye at the back, branching and sending nerves throughout the retina. The place where it enters and leaves the eye is the blind spot, as there are no light-sensitive cells there.

The retinal cells are light-sensitive. They receive images brought by light entering the eye and the optic nerve branches carry these to the main branch. That big main branch runs from the retina to the brain's vision center at the back of the head. The brain then interprets the data and finds names for it.

Glaucoma progressively damages the optic nerve, beginning with a subtle loss of peripheral (side) vision. Left undiagnosed and untreated, glaucoma can lead to a loss of central vision and eventually blindness.

How Glaucoma Damages the Optic Nerve
In most cases of glaucoma, elevated intraocular pressure (IOP) is the cause of damage to the optic nerve. There is another type of glaucoma that does not include a rise in IOP, but occurs due to insufficient blood flow to the optic nerve.

Normally, the eye is round and firm, and this shape is maintained by a normal IOP range between 8 and 22 millimeters of mercury. If IOP gets too low, the eye becomes softer. If IOP rises too high, it becomes firmer. The delicate optic nerve can be damaged by these internal pressure changes and by a consistently high IOP.

Causes of High IOP
Within the eye are structures we don't pay much attention to. Behind the cornea is a cavity (the anterior chamber) containing a clear fluid known as the aqueous humor. It provides moisture and nourishment to structures in the front of the eye.

The eye's lens is suspended behind the iris. Aqueous humor flows from behind the iris through the pupil into the anterior chamber. It then enters a tiny channel that runs around the outside of the cornea where it connects to the iris.

This connection point is a type of angle and there are others. In a normal eye, the angles remain open and clear at about 45 degrees. They filter the aqueous humor as it drains into the eye's capillaries and then into the main bloodstream.

In some individuals, the angle is too narrow. Fluid cannot drain properly, and it begins to back up. This increases the pressure inside the eye and eventually damages the optic nerve.

Glaucoma is the world's leading cause of irreversible blindness, with approximately six million individuals suffering blindness in both eyes. Three million of those people are in the United States. Since glaucoma causes no initial symptoms, and peripheral vision loss can be imperceptible at first, the majority of people with glaucoma are unaware they have the disease until it is discovered during a routine eye examination.

Glaucoma Risk Factors

-- Over 45 years of age
-- Family history of glaucoma
-- African American ancestry
-- Diabetes
-- History of elevated IOP
-- Nearsightedness
-- History of eye injury
-- Use of steroids, orally or injected
-- Farsightedness

Diagnosing Glaucoma
Several painless tests are used by a qualified ophthalmologist to determine intraocular pressure, health of the optic nerve and drainage angle. Visual field testing is also part of a glaucoma diagnosis.

Glaucoma is generally treated initially with eye drops. Laser surgery may be an option for more advanced cases. The main goal of treatment is to control intraocular pressure and prevent further loss of vision.

Since early diagnosis and treatment are the keys to preserving your sight, regular comprehensive eye examinations are the best prevention. If it has been some time since your last eye exam, or if you wonder about having glaucoma, do not delay.

If you are in Seattle, Washington or any of the surrounding communities, please contact ophthalmologist Dr. Kent Leavitt at Bellevue Lasik and Cornea.

Website: http://www.bellevue-lasik.com

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