What Is Optic Nerve Giloma

What is Optic Nerve Giloma?

Optic nerve glioma (also known as optic pathway glioma) is the most common primary neoplasm of the optic nerve. Along with reducing visual acuity in the affected eye, the tumor sometimes produces additional symptoms as it grows. A low-grade form of this neoplasm, benign optic glioma, occurs most often in pediatric patients. Another form, aggressive glioma, is most common in adults; it is frequently fatal, even with treatment. Gliomas are tumors that grow in various parts of the brain. Optic gliomas can affect:

·  One or both of the optic nerves, which carry visual information to the brain from each eye

·  The optic chiasm, the area where the optic nerves cross each other in front of the hypothalamus of the brain

An optic glioma may also grow along with a hypothalamic giloma.

Causes and Symptoms

Optic gliomas are rare. The cause of optic gliomas is unknown. Most optic gliomas are slow-growing and non-cancerous (benign) and occur in children, almost always before age 20. The symptoms are due to the tumor growing and pressing on the optic nerve and nearby structures. Symptoms may include:

Squinting or vision Loss in one or both eyes. May be a loss of peripheral vision or vision loss may be more genera. Leads to eventual blindness and Involuntary eyeball movement. One or both eyes may bulge outward.

Signs and Tests

A neurologic examination reveals a loss of vision in one or both eyes. There may be changes in the optic nerve, including swelling or scarring of the nerve, or paleness and atrophy of the optic disk.

The tumor may extend into deeper locations of the brain. There may be signs of increased pressure within the brain (intracranial pressure). There may be signs of NF1.

The following tests may be performed:

·  Head CT scan or MRI of the head -- confirms the diagnosis and the exact location of the tumor

·  Cerebral angiography-- often not necessary, but if used, it shows a space-occupying mass

·  Visual field tests can help determine how invasive the tumor is

·  Tissue removed from the tumor during surgery or Ct scan-guided biopsy -- examined to confirm the exact type of tumor.

Sources:

1.  http://emedicine.medscape.com/article/383533-overview

2.  http://www.healthline.com/adamcontent/optic-glioma

3.  http://www.healthcentral.com/ency/408/guides/000459.html

4.  http://www.nlm.nih.gov/medlineplus/ency/article/001024.htm

5.  http://www.eye.com.ph/on_glioma.htm