What is Glaucoma?
Glaucoma is a disease in which the optic nerve in the back of the eye is permanently damaged. In most cases the intraocular pressure is elevated (IOP) and leads to the damage. The intraocular pressure normally runs between ten to twenty one mmHg. There are some people who have glaucoma with a normal IOP and this is called normal pressure or low tension glaucoma. Approximately six million people in the United States have glaucoma.
The optic nerve takes the vision signal from the retina to the vision center in the brain. The elevated intraocular pressure causes damage and loss of the ganglion cells in the retina leading into the optic nerve. This damage causes a progressive loss of a person’s side vision which can take months or years. This usually occurs very slowly and therefore is called (the thief in the night). This can lead to permanent blindness as glaucoma damage is not reversible.
Types and Symptoms of Glaucoma
This constitutes the majority of glaucoma and is characterized by the slow gradual loss off side vision. It is called open angle as the angle between the iris and the cornea is open. The eye pressure gradually increases as there is a partial blockage of the drainage sytem in the eye (trabecular meshwork). Usually there is not any loss of visual acuity until the end stage of glaucoma (tunnel vision). It also does not have any symptoms until the vision loss is severe.
Angle Closure or Acute Narrow Angle Glaucoma
This is characterized by the sudden onset of symptoms as the intraocular pressure rises rapidly to a very high pressure. This is caused because the angle between the iris and the cornea is closed not allowing any fluid to exit the eye. Sudden onset of severe of pain in and around the eye with cloudy vision is classical. The eye becomes inflammed and red. There may be halos around lights and nausea vomiting is common. This is an emergency as the high IOP can cause permanent damage to the eye with loss of vision.
The symptoms of congenital glaucoma are usually noticed by the time the child is a few months old. Enlargement of the eyes with a cloudiness of the cornea are the common findings. The child’s eyes may be red, tearing, and be sensitive to light.