Optic pathway gliomas: a review.
Optic pathway gliomas represent approximately 3-5% of childhood intracranial tumors. They usually occur in children during the first decade of life and are seen in 11-30% of patients with neurofibromatosis Type 1 (NF1). Although these tumors are typically low-grade gliomas, the clinical course and natural history are highly variable, making treatment paradigms difficult. Overall, however, they are often indolent tumors that can be observed over time for progression without initial treatment, especially in patients with NF1. Chemotherapy is the first-line treatment for progressive tumors, and radiation therapy is reserved for patients with progressive disease who are older than 5-7 years. Surgery is reserved for large tumors causing mass effect or hydrocephalus and tumors confined to the orbit or unilateral optic nerve.