Normal-tension glaucoma typically means that glaucoma damage has been detected in an eye with so-called "normal" intraocular pressure (IOP)—that is, an eye that has not had documented pressure above 20 mm Hg. Ophthalmologists increasingly believe that this condition is a continuum of the same glaucoma process seen in those people with higher IOP.
Normal-tension glaucoma is diagnosed by examining the appearance of the optic nerve or by detecting abnormalities on visual field tests.
One large study showed that progressive damage and visual field loss can be significantly reduced in people with normal- tension glaucoma by lowering their IOP by 30% or more.
Other conditions can sometimes be mistaken for normal-tension glaucoma, so thorough eye and medical examinations are often required to make this diagnosis. Often the IOP will be measured at different times during the day to see if there are any pressure elevations. Other tests may also be necessary.
If your ophthalmologist (Eye M.D.) believes that you have normal-tension glaucoma, he or she may begin treatments to lower your IOP. This can be done with medications, laser treatment, or surgery.
Patients with adequately treated normal-tension glaucoma have a good prognosis, especially when the disease is caught early in its course.