Glaucoma

Learn more about Glaucoma from an eye doctor in your area!

InfoCenter

March 10, 2010

Glaucoma info and access to doctors who specialize in Glaucoma!

About Glaucoma
InfoCenter

Glaucoma InfoCenter is an Internet resource that offers you information about Glaucoma. Glaucoma InfoCenter does not offer medical advice or referrals.

Types of Glaucoma

Glaucoma refers to a group of illnesses that damage the optic nerve of the eyes. This disease affects millions of people, causing pain, vision problems and long-term vision loss. There are several different types of glaucoma that can impact vision.

Primary Open-Angle Glaucoma (POAG)

Primary open-angle glaucoma is often referred to as "the silent thief of sight" because there are few or no warning signs. Unfortunately, approximately half of people with glaucoma do not know they have the disease. Glaucoma gradually reduces your peripheral vision and by the time you notice the change in your eyesight, permanent damage has already occurred. If your intraocular pressure (IOP) continues to remain high, the damage to the eye can progress until tunnel vision develops, then you will only see objects that are straight ahead.

Normal-Tension Glaucoma (NTG)

Normal-tension glaucoma, also known as low-tension glaucoma, is a unique condition in which optic nerve damage and vision loss occurs despite normal intraocular pressure (IOP). Normal-tension glaucoma may result in the loss of peripheral vision. The condition is more common in women than in men and affects adults averaging 60-years-old. A common risk factor for normal-tension glaucoma is low blood pressure. Since elevated IOP is not a factor in normal-tension glaucoma, doctors are not sure what causes optic nerve damage. Possible causes of NTG are nerve irritation, premature nerve cell death, blood flow reduction, excessive glutamate production as well as autoimmune disease.

Primary Angle-Closure Glaucoma (PACG)

Closed-angle glaucoma occurs when the iris blocks intraocular fluid from draining properly. Closed-angle glaucoma may progress gradually without any symptoms until long after it has begun. Closed-angle glaucoma is rare, accounting for just 15 percent of all glaucoma cases in the country. This condition is caused by a structural defect within the eye that creates a narrow angle between the iris and cornea. If the iris moves forward, it can block the fluid drainage angle. This condition can be triggered by medications that dilate the pupil, such as antihistamines and tricyclic antidepressants. It can also occur naturally, when the eye dilates in low light. Farsighted individuals are at an increased risk for developing acute closed-angle glaucoma since their eyes have narrow drainage angles.

Pigmentary Glaucoma

Pigmentary glaucoma is often without symptoms, but patients will occasionally notice pain and blurry vision after exercise. Pigmentary glaucoma occurs when the pigment granules that normally adhere to the back of the iris (the colored part of the eye) flake off into the clear fluid produced in the eye. Additional problems can occur when these granules flow toward the drainage canals of the eye, slowly clogging them and raising eye pressure. The rise in eye pressure can damage the optic nerve, the nerve in the back of the eye that carries visual images to the brain. Men between the ages of 25-50 are affected more often than women. Studies have found that vigorous exercise seems to cause more pigment to be released from the iris, which may further block eye drainage.