Glaucoma most often develops from elevated intraocular pressure. This usually occurs when the eye does not drain fluid as well as it should, like a clogged drain. The front of the eye is normally filled with a clear fluid called Aqueous Humor, which is produced by the part of the eye called the ciliary body. The aqueous humor circulates through the front of the eye, passing through the pupil into the anterior chamber and then leaves through the drainage angle of the eye. The drainage angle is located where the colored part of the eye, known as the iris, meets the cornea. From here the fluid passes through the trabecular meshwork (the eye’s drain) into a series of drainage canals that feed back into the circulation and get absorbed into the bloodstream. The production, flow and drainage of this fluid is a continuous process that is necessary for the normal health and pressure of the eye.
Proper drainage of the intraocular fluid helps keep the eye pressure at a normal level. The intraocular pressure is dependent on the balance between the production and drainage of this fluid (aqueous humor) in the eye.
The most common type of glaucoma, called primary open angle glaucoma (POAG), typically occurs as a result of insufficient drainage of fluid due to partially blocked and poorly functioning drainage canals. This leads to a slow and gradual build-up of intraocular pressure which in turn causes progressive damage to the optic nerve fibers resulting in permanent and irreversible vision loss. Glaucoma is often referred to as the “silent thief of sight” because it gradually takes your peripheral vision first, without notice, and then starts affecting central vision and can progress to blindness. This is why it is important to see your eye doctor for regular check-ups and screening so that the disease can be diagnosed as early as possible and further damage can be prevented with appropriate treatment and management of the disease.
Who is at risk?
Some patients have a higher than normal risk of getting glaucoma. This includes people with: