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what is known as glaucoma? |
Glaucoma is the name for a group of eye conditions in which the optic nerve is damaged at the point where it leaves the eye. This nerve carries information from the light sensitive layer in your eye, the retina, to the brain where it is perceived as a picture. Your eye needs a certain amount of pressure to keep the eyeball in shape so that it can work properly. In some people, the damage is caused by raised eye pressure. Others may have an eye pressure within normal limits but damage occurs because there is a weakness in the optic nerve. In most cases both factors are involved but to a varying extent. Eye pressure is largely independent of blood pressure. There are four main types of glaucoma; Chronic glaucoma: The most common is chronic glaucoma in which the aqueous fluid can get to the drainage channels (open angle) but they slowly become blocked over many years. The eye pressure rises very slowly and there is no pain to show there is a problem, but the field of vision gradually becomes impaired. Acute glaucoma: Acute glaucoma is much less common in western countries. This happens when there is a sudden and more complete blockage to the flow of aqueous fluid to the eye. This is because a narrow “angle” closes to prevent fluid ever getting to the drainage channels. This can be quite painful and will cause permanent damage to your sight if not treated promptly. Secondary and developmental glaucoma: There are two other main types of glaucoma. When a rise in eye pressure is caused by another eye condition this is called secondary glaucoma. There is also a rare but potentially serious condition in babies called developmental or congenital glaucoma which is caused by malformation in the eye. |