An Overview Of The Four Major Types Of Glaucoma

The four major types of glaucoma are congenital, normal-tension, open-angle and angle-closure glaucoma. All types of glaucoma are caused by an increased pressure inside the eye, often called intraocular pressure (IOP).

Congenital Glaucoma

Congenital glaucoma, sometimes referred to as primary congenital glaucoma (PCG), begins before birth and is often genetic. It happens when the eye’s drainage canals do not form correctly in the womb.
Congenital glaucoma is diagnosed at birth or soon after, and can usually be corrected through microsurgery unless other complications are present, such as a secondary medical condition that might make microsurgery dangerous. Otherwise, the condition can be treated by medication and other types of surgery.

Normal-Tension Glaucoma

Normal-tension glaucoma means that the optic nerve has been damaged but IOP is not very high. Exactly how some individuals incur nerve damage to the eye without affecting the IOP is uncertain. The symptoms of normal-tension glaucoma are similar to those of open-angle glaucoma, which is the most common form.
Treatment for normal-tension glaucoma includes specially medicated eye drops designed to keep the IOP low. This type of medication can usually keep this condition stable and stop further deterioration of vision. Otherwise, surgery will result.
This type of glaucoma is also referred to as low-tension or normal-pressure glaucoma.

Open-Angle Glaucoma

Open-angle glaucoma is the most common glaucoma diagnosis, accounting for at least 90 percent of glaucoma cases and affecting over 3 million Americans (Glaucoma Research Foundation, 2011).This type of glaucoma results from the slow clogging of the drainage canals which results in increased levels of IOP.
Open-angle glaucoma is characterized by a wide and open angle between the cornea and the iris. It often has symptoms that go unnoticed. It’s a lifelong condition that is slow to develop.
Because it’s the most prevalent form, it’s often called primary glaucoma. Because it’s a lifelong condition, it’s also referred to as chronic glaucoma.

Angle-Closure Glaucoma

Angle-closure glaucoma is a less common form of glaucoma that is caused by blocked drainage canals that result in a sudden rise in intraocular pressure. It typically develops rapidly and requires the immediate intervention of a specialist.
This form of glaucoma is referred to as acute or narrow-angle glaucoma. It’s characterized by a narrow or closed angle between the cornea and the iris.
The methods of treating glaucoma will vary depending on the type of glaucoma present.