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 glioma.
Glioma - optic; Optic nerve glioma; Juvenile pilocytic astrocytoma
Causes, incidence, and risk factors
Optic gliomas are rare. The cause of optic gliomas is unknown. Most optic gliomas are slow-growing and noncancerous (benign) and occur in children, almost always before age 20.
There is a strong association between optic glioma and neurofibromatosis Type 1 (NF1).
The symptoms are due to the tumor growing and pressing on the optic nerve and nearby structures. Symptoms may include:
- Involuntary eyeball movement
- One or both eyes bulge outward
- Vision loss in one or both eyes
The child may show symptoms of diencephalic syndrome, which includes:
- Daytime sleeping
- Decreased memory and brain function
- Delayed growth
- Loss of appetite and body fat
Signs and tests
A brain and nervous system (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 damage to the optic disc.
The tumor may extend into deeper parts of the brain. There may be signs of increased pressure in the brain (intracranial pressure). There may be signs of neurofibromatosis type 1 (NF1).
The following tests may be performed:
- Cerebral angiography
- Examination of tissue removed from the tumor during surgery or CT scan-guided biopsy to confirm the tumor type
- Head CT scan or MRI of the head
- Visual field tests
Treatment varies with the size of the tumor and the general health of the person. The goal may be to cure the disorder, relieve symptoms, or improve vision and comfort.
Surgery to remove the tumor may cure some optic gliomas. Partial removal to reduce the size of the tumor can be done in many cases. This will keep the tumor from damaging normal brain tissue around it.
Radiation therapy may be recommended in some cases where the tumor is larger and surgery is not possible. In some cases, radiation therapy may be delayed because the tumor is slow growing.
Corticosteroids may be prescribed to reduce swelling and inflammation during radiation therapy, or if symptoms return.
Chemotherapy may be used in some children. Chemotherapy may be especially useful when the tumor extends into the hypothalamus.
For organizations that provide support and additional information, see blindness resources.
The outlook is highly variable. Early treatment improves the chance of a good outcome. Many tumors are curable with surgery, while others return.
Normally, the growth of the tumor is very slow, and the condition remains stable for long periods of time. However, in adults and some childhood cases where the optic chiasm is involved, the tumor behaves aggressively.
Calling your health care provider
Call your health care provider for any vision loss, painless bulging of the eye, or other symptoms of this condition.
Genetic counseling may be advised for people with neurofibromatosis-1. Regular eye exams may allow early diagnosis of these tumors before they cause symptoms.
Karcioglu ZA, Haik BG. Eye, orbit, and adnexal structures. In: Abeloff MD, Armitage JO, Niederhuber JE, Kastan MB, McKenna WG, eds. Abeloff's Clinical Oncology. 4th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 71.
Olitsky SE, Hug D, Plummer LS, Strass-Isern M. Abnormalities of the optic nerve. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 623.
Reviewed by:Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington; and Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.
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