Adult glaucoma falls into two categories :
- Open Angle glaucoma
- Closed Angle glaucoma
These are marked by increase of intra ocular pressure (IOP), or pressure inside the eye.
Open Angle Glaucoma
This is the most common form of glaucoma. Think of the eye as a sink with a tap that is always open. The water flows through if the drainage mechanism is working all right. The trouble arises when the drainage is clogged and the water begins to collect.
In the same way, the inside of the eye contains fluid that is constantly flowing and is drained out of the eye. Glaucoma happens when the eye’s drainage canals become clogged. The pressure inside the eye (also called intraocular pressure or IOP) rises because the correct amount of fluid can’t drain out of the eye. This results in the fluid accumulating in the eye and over a period of time it leads o increased intra ocular pressure. Over a period of time, this high pressure inside the eye (IOP) can damage the optic nerve (or nerve of the eye)
Most people have no symptoms and no early warning signs. If open angle glaucoma is not diagnosed and treated, it can cause a gradual loss of vision. This type of glaucoma develops slowly and sometimes without noticeable sight loss for many years. It usually responds well to medication, especially if caught early and treated.
Angle Closure Glaucoma
This type of glaucoma is also known as acute glaucoma or narrow angle glaucoma. It is very different from open angle glaucoma in that the eye pressure usually rises very quickly.
This happens when the drainage canals get blocked or covered over, like a sink with something covering the drain. With angle closure glaucoma, the iris is not as wide and open as it should be. The outer edge of the iris bunches up over the drainage canals, when the pupil enlarges too much or too quickly. This can happen when entering a dark room.
Treatment of angle closure glaucoma usually involves surgery to remove a small portion of the outer edge of the iris. This helps unblock the drainage canals so that the extra fluid can drain. Usually surgery is successful and long lasting. However, you should still receive regular check-ups.
Symptoms of angle closure glaucoma: include headaches, eye pain, nausea, rainbows around lights at night, and very blurred vision.