What is Normal Tension Glaucoma?
Like most chronic forms of glaucoma, there are no symptoms in normal tension glaucoma until very late in the disease when vision loss occurs. The patient is typically elderly, and there is a higher incidence among females. Many patients with normal tension glaucoma also have vasospastic conditions, such as migraine and Raynaud's phenomenon. There appears to be an increased prevalence of systemic autoimmune diseases associated with normal tension glaucoma.
What causes Normal Tension Glaucoma?
There are multiple theories for the exact cause of normal tension glaucoma, and open angle glaucoma in general. Most experts agree that more than one factor can play a role in the development of normal tension glaucoma. Some of those factors include:
Intraocular pressure: even though your pressure may be considered “normal” by most standards, it can still be too high for you individually.
Family history of glaucoma
Race: certain races are at higher risk of developing glaucoma, such as African-Americans. Asian cultures appear to be at a higher risk for normal tension glaucoma.
Vascular dysregulation, such as systemic or nocturnal hypotension, vasospasm, or loss of autoregulation
Symptoms of Normal Tension Glaucoma:
Typically there are no obvious symptoms associated with normal tension glaucoma, particularly in the early stages. Some symptoms that may develop if left untreated can include noticing that parts of a page are missing. This can progress further into tunnel vision and a loss of central fixation.
Treatment for Normal Tension Glaucoma:
Much like primary open angle glaucoma, treatment for normal tension glaucoma is typically aimed at reducing the pressure inside the eye. This is typically done by the use of medicated eye drops 1-3 times per day. Any associated cardiovascular problems should also be addressed by an internist or cardiologist.