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Optic glioma Causes and Risks:
Optic glioma is classified as an astrocytoma . Optic gliomas cause symptoms by invasion (pressure) and displacement (destruction) of normal optic nerve tissue. They may result in progressive loss of vision in one or both eyes. The cause of optic glioma is unknown. Tumors may occur at any age. Optic glioma and other astrocytomas are rare (however, astrocytomas in general are the most common primary brain tumors in adults). There is a strong association between optic glioma and neurofibromatosis Type 1 ( NF1 ).
Prevention:
Genetic counseling may be advised for people with neurofibromatosis-1 .
Symptoms:
Signs and Tests:
An examination shows vision losses in one or both eyes, including visual field defects. There may be optic disc or nerve head changes in the optic nerve, including papilledema (swelling of the nerve), or paleness and atrophy of the optic disk. There may be indications of astrocytoma in other locations of the brain, including signs of increased pressure within the brain (intracranial pressure). There may be signs of NF1 .
- A head CT scan or MRI of the head confirms the diagnosis and the exact location of the tumor .
- A cerebral angiography is not often necessary, but if used, it shows a space-occupying mass which is not vascular.
- An EEG is not often useful in the diagnosis of optic glioma, but may reveal focal (localized) abnormalities if there are other astrocytomas present in the brain.
- An examination of tissue removed from the tumor during surgery or CT scan-guided biopsy is used to confirm the exact type of tumor.
Treatment:
Treatment varies with the size of the tumor and the general health of the person. Treatment goals may be cure of the disorder, relief of symptoms, improvement of functioning, or comfort.
Surgical excision (removal) is curative for some optic gliomas. Partial resection to remove some of the bulk of the tumor is feasible for many cases, which will reduce pressure-induced damage from the tumor. Radiation therapy may be advised in some cases. In some cases it may be delayed because of the slow growth that this tumor typically displays. Corticosteroids may be prescribed to reduce swelling and inflammation during radiation therapy, or when symptoms recur.
The stress of illness can often be helped by joining a support group where members share common experiences and problems. See blindness - support group and cancer - support group .
Prognosis:
The probable outcome is highly variable. Early treatment improves the chance of a good outcome. Some tumors are curable with surgery, while others recur. Normally, the growth of the tumor is very slow, and the condition remains stable for long periods of time.
Complications:
Call Your Healthcare Provider:
Call your health care provider if vision losses occur.
This X-ray shows the skull of a child with neurofibromatosis (NF-1). This child developed visual difficulties and was discovered to have a glioma (nerve tumor) in the optic nerve. The tumor has enlarged the bony opening (optic foramen), through which the optic nerve passes. This can be seen on the right side of picture.
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