There are several types of glaucoma. The two main types are open-angle and angle-closure. These are linked to an increase of intraocular pressure (IOP) or pressure inside the eye.
Open-angle glaucoma– the most common form of glaucoma, accounting for at least 90% of all glaucoma cases:
“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 known as primary or chronic glaucoma.
Angle-closure glaucoma- a less common form of glaucoma:
It is also known as 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 known 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 few people’s optic nerves are damaged even though they have almost normal pressure levels.
This type of glaucoma occurs in child when there is incorrect or incomplete development of the eye’s drainage canals during the prenatal period. It 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.