Glaucoma Is a Group of

Glaucoma is a group of eye diseases that damages the optic nerve resulting in vision loss and blindness if not treated in time. It is the second most common cause of blindness worldwide and usually occurs due to increased pressure in the eye. ("Susceptibility to...") Types of Glaucoma: Open Angle Glaucoma is the most common type, causing a gradual loss of vision. It usually occurs due to increased pressure within the eye and sometimes due to decreased blood flow to the optic nerve. Closed Angle Glaucoma is less common.

It occurs when the iris and the lens block the movement of fluid between the chambers of the eye, causing pressure to build up. Congenital Glaucoma is a form of glaucoma that affects some infants at birth causing cloudy and teary eyes. Severe vision loss or blindness may occur if not detected and treated at an early stage. Secondary Glaucoma refers to glaucoma which develops due to external reasons such as eye injury, tumor, complication of diabetes, or a reaction to eye medication such as corticosteroids.

("Topic Overview," Glaucoma: Yahoo Health,) Risk Factors Age, race, family history / genetics, and medical history are some of the notable risk factors. Older people (over 70) are 4 to 7 times more likely to have glaucoma than people 40 to 50 years old. African-Americans are 4 to 5 times than white Americans susceptible to the disease; people with family history of open-angle glaucoma have about 9 times greater risk of developing glaucoma; and medical history of previous eye injuries, eye surgery or long-term steroid also increase one's risk of glaucoma.

("What Increases Your Risk?"; "Who is at Risk...") Symptoms: The symptom of "open-angle glaucoma" is a gradual vision loss which usually goes un-noticed until substantial vision loss has occurred; loss of peripheral vision occurs before the loss of central vision. Symptoms of "closed-angle glaucoma" are often episodic, occurring in the evening and ending by morning; at other times they can be severe with sudden, severe blurring of vision; severe pain in the eye; eye redness; or nausea and vomiting.

Congenital glaucoma causes watery eyes, sensitivity to light, cloudy eyes, or larger than normal eyes; rubbing, squinting, or keeping their eyes closed by babies are its other tell-tale signs.

("Topic Overview," Glaucoma: Yahoo Health, para on "What are the Symptoms?") Diagnosis Glaucoma is diagnosed by an ophthalmologist through a comprehensive eye exam that includes a visual acuity test, which measures the eyesight at various distances; a visual field test to measure the peripheral vision; tonometry, to measure the pressure inside the eye; dilated eye exam for examining the retina and optic nerve for signs of damage by putting special dilatory eye-drops in the eye; and by pachymetry, measurement of the thickness of the cornea by using an ultrasonic wave instrument.

("Glaucoma" National Eye Institute, "How is Glaucoma Detected?") Treatment Treatment for glaucoma is aimed at slowing the damage to the optic nerve. In adults, the eyesight already lost cannot be reversed while in children with congenital glaucoma some reversal is possible. Most treatments consist of lowering of the pressure in the eye (the intraocular pressure) through medication, laser treatment, or conventional surgery.

The treatment is usually started with medicines, i.e., eye drops or pills that either cause the eye to make less fluid or lower pressure by helping to drain the fluid from the eye. If the medications.