The growth rate of optic pathway
gliomas (OPGs) is unpredictable and quite variable, especially in children with
neurofibromatosis Type 1 (NF1). Close neuroophthalmalogical clinical follow-up with serial imaging (magnetic resonance imaging of the brain with and without contrast enhancement) is the recommended initial step in management to establish the growth rate of the lesion in an individual patient. Typically, only symptomatic and/or radiographically growing
tumors require treatment, and observation is the accepted first-line option. Although both
chemotherapy and
radiotherapy can stabilize growth or even decrease the size of
tumors,
chemotherapy, especially in younger patients, has fewer side effects than
radiation therapy (such as secondary
tumors, radiation
necrosis, and Moyomoya disease) and is generally considered the first-line treatment for progressive lesions in younger patients. The
tumor location defines prognosis in OPGs;
optic nerve gliomas (ONG) have the lowest rate of complications and death, and optic chiasm and retrochiasmal
gliomas the highest. Although the major complication of an OPG is visual loss, hypothalamic involvement can lead to death. Resection is an option for ONGs but is generally reserved for
tumors confined to the optic nerve with poor or no vision, or for patients with severe, cosmetically unappealing
proptosis, producing severe
pain or exposure keratopathy in a blind eye. Resection is generally not an option for intrinsic chiasmal or retrochiasmal OPGs. Extrinsic (exophytic) components can be debulked surgically, and surgery can be performed for
hydrocephalus (
ventriculoperitoneal shunt placement). The approach to a patient with OPG must be individualized based on
tumor location, radiographic or
clinical progression, the presence of NF1, and a risk-benefit comparison for treatment.