The primary forms of glaucoma are open-angle and narrow-angle, with open-angle being the most common type.
Primary open-angle glaucoma (POAG)
POAG gradually progresses without pain or noticeable vision loss initially affecting peripheral vision. By the time visual symptoms appear, irreparable damage has usually occurred, however, the sooner treatment starts the more vision loss can be prevented. When untreated, vision loss will eventually result in total loss of side vision (or tunnel vision) and eventually total vision loss.
Normal-tension glaucoma or low-tension glaucoma
This is another form of open-angle glaucoma in which the intraocular pressure remains within the normal level. The cause of this form of glaucoma is not known, but it is believed to have something to do with insufficient blood flow to the optic nerve, causing damage. Individuals of Japanese descent, women and those with a history of vascular disease or low blood pressure are at higher risk.
Acute angle-closure glaucoma is marked by a sudden increase in eye pressure, which can cause severe pain, blurred vision, halos, nausea, and headaches. The pressure is caused by a blockage in the fluid at the front of the eye which is a medical emergency and should be treated immediately. Without prompt treatment to clear the blockage vision can be permanently lost.
The inherited form of the disease that is present at birth. In these cases, babies are born with a defect that slows the normal drainage of fluid out of the eye; they are usually diagnosed by the time they turn one. There are typically some noticeable symptoms such as excessive tearing, cloudiness or haziness of the eyes, large or protruding eyes or light sensitivity. Surgery is usually performed, with a very high success rate, to restore full vision.
Glaucoma can develop as a complication of eye surgeries, injuries or other medical conditions such as cataracts, tumors, or a condition called uveitis which causes inflammation. Uncontrolled high blood pressure or diabetes can result in another serious form called neovascular glaucoma.
A rare form of glaucoma, this occurs when pigment from the iris sheds and clogs the drainage of fluid from the eye resulting in inflammation and damage to the eye and drainage system.
Treatment of glaucoma is dependent upon the severity and type of glaucoma present.