Glaucoma de tensión normal: Preguntas y respuestas

También llamado glaucoma de baja presión o glaucoma de presión normal, el glaucoma de tensión normal (GTN) es una afección en la cual el nervio óptico está dañado y la presión ocular no supera el rango promedio (generalmente entre 12 y 21 mm Hg).

What is normal tension glaucoma?

Also called low-pressure glaucoma or normal pressure glaucoma, normal tension glaucoma (NTG) is a condition in which the optic nerve is damaged and the eye pressure does not exceed the average range (usually between 12 and 21 mm Hg). There is debate among glaucoma experts about whether  GTN  is a separate entity from primary open-angle glaucoma (POAG) or whether it is simply another form of  POAG.

Why is normal tension glaucoma different?

Whether or not  GTN  is a separate entity from  POAG,  there are some characteristics that appear to be more common in  GTN  than  POAG.  Patients who have  GTN  tend to have visual field abnormalities closer to the center of vision. Additionally, hemorrhages in the small blood vessels of the optic nerve tend to be more common in patients who have  GTN.  GTN  has been associated with migraines and low blood pressure

What are the causes of normal tension glaucoma?

It is thought that factors unrelated to eye pressure may play a more important role in  GTN  than in  POAG.  These factors include abnormalities in blood flow to the optic nerve, and structural weakness of the optic nerve tissue. Researchers continue to investigate why some optic nerves are damaged by relatively low levels of eye pressure.

How is normal tension glaucoma diagnosed?

GTN  is diagnosed by using  the same tests used for  POAG.  Additionally, your doctor may obtain several eye pressure measurements at different times of the day to make sure your eye pressure is within the average range. In some cases, if the appearance of the optic nerve is not typical for glaucoma, your doctor may recommend imaging of the brain and optic nerve to rule out other causes of optic nerve damage.

How is normal tension glaucoma treated?

Normal tension glaucoma is treated in the same way as  POAG  by lowering eye pressure through the use of medications, laser treatment, and surgery. Blood flow to the optic nerve may play an important role in  GTN,  but there is currently no treatment that can directly modify it. Overtreating high blood pressure with medications can affect blood flow to the optic nerve. Your ophthalmologist may suggest talking to your primary care doctor about adjusting your medications to maintain optimal blood pressure.

Sunita Radhakrishnan, MD

Sunita Radhakrishnan, MD

Sunita Radhakrishnan, MD specializes in the medical and surgical treatment of glaucoma at the Glaucoma Center of San Francisco and is Research Director at the Glaucoma Research and Education Group in San Francisco.