Low-tension glaucoma, also referred to as normal-tension, is a type of glaucoma that does not increase the pressure in the eye. The typical form of glaucoma is marked by increased pressure, which is why the low-tension kind is differentiated by its name. The main cause of this kind of glaucoma is thought to be pressure that is too low to supply enough blood to the optic nerve. This typically results in vision loss. Treatment is available, and typically aims to increase the blood flow the optic nerve so that less damage occurs.
In most cases of glaucoma, abnormally high pressure inside the eye can cause damage to the optic nerve, eventually leading to vision loss. It can be detected by an eye doctor through a test that screens for high pressure inside the eye, but low-tension glaucoma cannot be diagnosed this way since the pressure levels are always within the normal range. Unfortunately, despite normal pressure, the result of this condition is usually the same as typical glaucoma, which is optic nerve damage and vision loss.
Not much is known about low-tension glaucoma except that it is likely caused by too little blood reaching the optic nerve. Though this condition cannot be diagnosed with a regular intraocular eye pressure test, it can be detected by a doctor getting a close look at the optic nerve to check for damage. This can be done by holding an ophthalmoscope, which permits the doctor to see the shape and hue of the optic nerve by looking through the pupil. A nerve that is anything other than pink can signal a problem, as can one that is cupped. Another screening measure often completed by eye doctors is a visual field test, as loss of vision can be a sign of low-tension glaucoma.
Some people are more prone to this condition than others. For example, it has been found that women are more prone than men, along with those with cardiovascular disease, adults over age 60, and people of Japanese origin are the most susceptible to low-tension glaucoma. Fortunately, treatment is available, usually in the form of eye drops or laser procedures. The point of treatment for this condition is to increase blood flow to the eye if possible. In some cases, surgery may be necessary in order to let some of the fluid out of the eye so that it is soft, allowing more blood to flow to the optic nerve.