Glaucoma is actually a group of eye diseases, not just one disease. Glaucoma can exist in many forms, and can be the result of a number of different factors.
Generally speaking, there are two major categories of glaucoma: open-angle glaucoma and narrow-angle or angle-closure glaucoma. But there are also secondary causes of these two major types, as well as developmental forms of glaucoma that occur in babies, children, and adolescents.
The buttons below link to discussions about the causes of various forms of glaucoma. To better understand the types and causes of glaucoma, we must first discuss some aspects of eye anatomy and how the eye functions.
The eye produces a fluid called aqueous humor, which provides nutrition to the eye, as well as maintains the eye in a pressurized state. The aqueous humor is continually produced, and drains out of the trabecular meshwork, which is a network of cells and scaffolding material that sits in an area called the drainage angle.
The angle can be thought of as the angle between the iris and the cornea, although that is an oversimplification. This drainage angle wraps 360 degrees around the circumference of the front part of the eye.