Glaucoma: An Overview
Reviewed by Karanjit S. Kooner, M.D.
Glaucoma is a group of eye diseases that can lead to blindness by damaging the optic nerve. The eye continuously produces a fluid, called the aqueous, that must drain from the eye to maintain healthy eye pressure.
In Primary Open Angle Glaucoma, which is the most common type of glaucoma, the eye’s drainage canals become blocked, and the fluid accumulation causes pressure to build within the eye. This pressure can cause damage to the optic nerve, which transmits information from the eye to the brain for processing.
Glaucoma results in peripheral (or side) vision loss initially, and the effect can be like looking through a tube or into a narrow tunnel. This “tunnel vision” effect makes it difficult to walk without bumping into objects that are off to the side, near the head, or at foot level:
This is a representation of peripheral vision loss, or a constricted visual field:
A living room viewed through a constricted visual field.
Source: Making Life More Livable. Used with permission.
Glaucoma is an especially dangerous eye condition because most people do not experience any symptoms or early warning signs at the onset of glaucoma. This is why glaucoma is often called “the sneak thief of sight.”
Glaucoma Can Be Treated, Not Cured
Glaucoma can be treated, but it is not curable. The damage to the optic nerve from glaucoma cannot be reversed. However, lowering the pressure in the eye can help prevent further damage to the optic nerve and further peripheral vision loss.
Early detection, appropriate and ongoing treatment, and the availability of specialized low vision and vision rehabilitation services can help people with glaucoma live productive and satisfying lives.
Starting as early as age 35, an eye pressure check (also called tonometry) for glaucoma should be an essential part of your annual comprehensive eye examination. In addition, a visual field test can detect peripheral vision loss before you may even notice it.
For more detailed and patient-centered information about glaucoma detection, treatment, and everyday management, see VisionAware’s Patient’s Guide to Living with Glaucoma and Guía del Paciente: Vivir con Glaucoma.