Frequently Asked Questions

Glaucoma is actually a group of eye diseases that lead to damage of the optic nerve (the bundle of nerve fibers that carries information from the eye to the brain), which can then lead to vision loss and possibly blindness. Optic nerve damage usually occurs in the presence of high eye (intraocular) pressure; however, it can occur with normal or even less than normal eye pressure. Glaucoma is estimated to affect approximately three million Americans, but up to half of these individuals may be unaware that they have the disease. Worldwide, an estimated 66.8 million people are visually impaired due to glaucoma, and an estimated 6.7 million are blind.

In glaucoma, it is optic nerve damage that can lead to vision loss and possibly blindness. In many people, fluid pressure increases inside the eye and damages the optic nerve (the bundle of nerve fibers that carries information from the eye to the brain). Elevated eye pressure increases the risk of developing glaucoma; however, the disease can occur in people with normal or even lower than normal eye pressure. In addition, individuals with higher than normal eye pressure do not always develop the symptoms of glaucoma. Since normal-tension glaucoma does not involve high eye pressure, it is diagnosed by observing the optic nerve for any signs of damage. The eye doctor will use an ophthalmoscope to look through the pupil at the shape and color of the optic nerve. In addition, a visual field test can help determine if there is any loss of peripheral vision.

The risk factors for developing normal-tension glaucoma include a family history of glaucoma, low eye pressure, and cardiovascular disease. Ongoing research is aimed at determining all of the factors that contribute to the optic nerve damage. For example, scientists believe the optic nerve may be affected by blood flow in the eye. They are also investigating susceptibility and genetic factors.