Glaucoma is the second leading cause of blindness. Sometimes called the silent thief of sight, glaucoma can damage your vision so gradually you don’t notice any loss of vision until the disease is at an advanced stage. Glaucoma is an eye condition that develops when too much fluid pressure builds up inside of the eye. This increase in pressure, called intraocular pressure, can damage the optic nerve, which transmits images to the brain. If damage to the optic nerve from high eye pressure continues, glaucoma will cause loss of vision. Without treatment, glaucoma can cause total permanent blindness within a few years.
Because most people with glaucoma have no early symptoms or pain from this increased pressure, it is important to have regular routine eye exams so that glaucoma can be diagnosed and treated before long-term visual loss occurs.
There are two main types of glaucoma:
- Open-angle glaucoma. This is the most common type of glaucoma. The structures of the eye appear normal, but fluid in the eye does not flow properly through the drain of the eye, called the trabecular meshwork.
- Angle-closure glaucoma. This type of glaucoma is less common, but can cause a sudden buildup of pressure in the eye. Drainage may be poor because the angle between the iris and the cornea (where a drainage channel for the eye is located) is too narrow. Or, the pupil opens too wide, narrowing the angle and blocking the flow of the fluid through that channel.