Glaucoma is a progressive eye disease where the optic nerve is damaged, causing blind spots (squares) to develop in the patient’s vision. The disease affects some people more than others, but it never reverses once it is present. Even if the damage is repaired, the eye has lost functioning neurons and cannot regain its vision once the damage has occurred.
There are two primary causes of glaucoma – low eye pressure (normal-tension glaucoma) or abnormally high eye pressure (high-tension glaucoma). The best current treatment for glaucoma is lowering eye pressure, regardless of the underlying cause. Further, the more pressure that is lowered, the greater the likelihood of the disease being controlled and vision being saved.
The 'Glaucoma' page explains that Glaucoma is caused by high pressure within the eye.
The 'What is the relationship between intraocular pressure and glaucoma?' page explains, that "while increased eye pressure is generally correlated with glaucoma, it is not the only indicator of the disease."
The 'How does the eye pressure relate to glaucoma?' page explains that the eye has two sets of lenses to help focus light and help produce images in your eye. You also have a thin layer of tissue called the cornea.
The 'Cornea' page explains the cornea is the clear outer covering of your eye that is shaped like a dome.
The 'What is cornea endothelial dystrophy?' page explains that the cornea contains several types of cells including the endothelial cells, which are the most common cells of the cornea and maintain a thick and stable cornea.
The 'What is Trabecular meshwork?' page explains the eyehas several drainage structures. One of these is the trabecular meshwork (trabecular meaning porous).
The 'What is aqueous humor and where is it located?' page explains that the aqueous humor is fluid that fills the front part of your eye.
The 'The pressure of a fluid' page explains how eye pressure is created by the eye. The pressure is created by the contraction of muscles
The 'Glaucoma' page gives the definition of Glaucoma.
Glaucoma is a group of eye conditions that causes damage to the optic nerve and can lead to blindness. There are many types of glaucoma.
Glaucoma may be caused by high eye pressure, which is known as Open Angle Glaucoma. Other types of glaucoma are due to narrowed drainage canals, and sometimes cause increased pressure in the eye, however other times it can be a low pressure type.
The eyes work like a waterfall. If the water is flowing too fast, or the waterfall is too small the water will flow into the eye, which is too large, and may cause swelling or clouding in the eye.
Familial glaucoma is about 25% of all primary open angle glaucoma (which is the form of glaucoma common in the majority of humans). Most of the genes involved are specific to certain forms of open angle glaucoma.
The population risk for having glaucoma in the US and other countries is approximately 1 in 10. Thus, there are probably 2.5% people with glaucoma who are close relatives of a person with the disease.
Open angle glaucoma is usually diagnosed in the mid-fifties. Genes associated with the disease are very likely to be expressed during growth and development. If a child inherits genes associated with open angle glaucoma, they will develop the disease (in a later stage of life) with a higher probability than the general population.
People with less than three siblings were determined to be at a higher risk of developing glaucoma, a marker for less diversity in the family (eg the less genetic diversity you have, the higher your risk of developing glaucoma).