Types of Glaucoma

There are several types of glaucoma. The two main types are open-angle and angle-closure. These are marked by an increase of intraocular pressure (IOP), or pressure inside the eye.

Open-Angle Glaucoma
poag_illus.jpg

Open-angle glaucoma, the most common form of glaucoma, accounting for at least 90% of all glaucoma cases:

  • Is caused by the slow clogging of the drainage canals, resulting in increased eye pressure
  • Has a wide and open angle between the iris and cornea
  • Develops slowly and is a lifelong condition
  • Has symptoms and damage that are not noticed.

“Open-angle” means that the angle where the iris meets the cornea is as wide and open as it should be. Open-angle glaucoma is also called primary or chronic glaucoma. It is the most common type of glaucoma, affecting about three million Americans.

Angle-Closure Glaucoma
acg_illus.jpg

Angle-closure glaucoma, a less common form of glaucoma:

  • Is caused by blocked drainage canals, resulting in a sudden rise in intraocular pressure
  • Has a closed or narrow angle between the iris and cornea
  • Develops very quickly
  • Has symptoms and damage that are usually very noticeable
  • Demands immediate medical attention.

It is also called acute glaucoma or narrow-angle glaucoma. Unlike open-angle glaucoma, angle-closure glaucoma is a result of the angle between the iris and cornea closing.

Normal-Tension Glaucoma (NTG)

Also called low-tension or normal-pressure glaucoma. In normal-tension glaucoma the optic nerve is damaged even though the eye pressure is not very high. We still don't know why some people’s optic nerves are damaged even though they have almost normal pressure levels.

Read more about normal-tension glaucoma

Congenital Glaucoma

This type of glaucoma occurs in babies when there is incorrect or incomplete development of the eye's drainage canals during the prenatal period. This is a rare condition that may be inherited. When uncomplicated, microsurgery can often correct the structural defects. Other cases are treated with medication and surgery.

Read more about congenital (childhood) glaucoma

Other Types of Glaucoma

Variants of open-angle and angle-closure glaucoma include:

  • Secondary Glaucoma
  • Pigmentary Glaucoma
  • Pseudoexfoliative Glaucoma
  • Traumatic Glaucoma
  • Neovascular Glaucoma
  • Irido Corneal Endothelial Syndrome (ICE)

Read more about other types of glaucoma

Last reviewed on June 11, 2013

This article appeared in the May 2010 issue of Gleams. Subscribe

Was this helpful? Yes No