These tumors are more common in children with neurofibromatosis type 1 (NF1) syndrome. Optic gliomas can grow between the normal nerve cells (diffuse), causing a thickening of the optic nerve or chiasma. Optic gliomas can also grow into large tumors of the optic chiasma. Metastases of an optic glioma in the central nervous system are rare.
Symptoms of this disease
Children with this disease almost always have visual problems. For example, they may see less clearly or part of the field of vision may fail. There are sometimes abnormal eye movements (nystagmus) or an abnormal eye position. In case of a tumor in the chiasma region, the pituitary gland and/or the hypothalamus may be involved. This affects hormone production, leading to symptoms such as being short, early puberty or obesity.
How do we make the diagnosis?
In case there is suspicion on an optic glioma, an MRI will always be performed in addition to an ophthalmic examination.
Treatment of an optic glioma
The need for and method of treatment can vary greatly from patient to patient. This is discussed for children with an optic glioma in a multi-disciplinary tumor working group, which includes a neurosurgeon, pediatrician oncologist, radiotherapist, pediatric neurologist, neuroradiologist, endocrinologist, ophthalmologist and neuropathologist. Together they determine which treatment your child will receive.
Depending on the location of the optic glioma, a decision is made on whether to perform a biopsy or to remove the tumor.
For large chiasma tumors, a biopsy will usually be performed so that the neuropathologist can identify the type of tissue involved. The nature of the tumor is almost always low-grade, usually a pilocytic astrocytoma. A small number of children with an optic glioma do not receive a biopsy, mostly children with NF1.
The choice of treatment depends on, among other things, the symptoms (vision / hormones / neurology), the location of the tumor, the age of the child and possibly NF1.
- A wait-and-see policy is used for some children.
- In the event of impaired vision and/or neurological failure, treatment will almost always be given with the aim of stabilizing tumor growth and failure. This will usually be in the form of chemotherapy.
- In the case of a very large tumor that does not respond well to chemotherapy, a further option would be the partial surgical removal of the tumor. The tumor can never be completely removed without causing blindness and hormonal failure. The purpose of the treatment will always be tumor control.
- Sometimes local radiotherapy is performed for older children.
The optic glioma is almost always a chronic condition, sometimes with many treatment stages over time. This treatment needs to be customized for each patient and requires long-term intensive monitoring. Treatments are provided as far as possible in the context of study.