Orbital optic nerve gliomas in children with neurofibromatosis type 1

To describe the clinical course and treatment of symptomatic orbital optic nerve gliomas in children with neurofibromatosis type-1 (NF-1).

A retrospective review of the records of patients with NF-1 and symptomatic orbital optic nerve gliomas seen in a large multidisciplinary NF-1 clinic of a tertiary care children's hospital. The main outcome measures included presenting symptoms and signs, ophthalmologic examination at diagnosis, the presence of progressive disease following diagnosis, type of therapy, and the reasons therapy was instituted.

Twelve patients with symptomatic orbital optic nerve gliomas, all of which led to proptosis (eight girls, four boys), were identified. The mean age of diagnosis of NF-1 was 20 months; the mean age of diagnosis of the orbital optic nerve glioma was 26 months. At the time of diagnosis of the tumor, 10 of 12 patients (83%) had decreased visual acuity in the affected eye. Three patients underwent optic nerve resection; eight received chemotherapy, and one was observed without therapy. Of the eight children who received chemotherapy, progressive disease prior to treatment could be documented in only three; none of these eight children had a reproducible improvement in vision following chemotherapy. There was no demonstrable improvement in vision in any treated patient with NF-1-associated orbital optic nerve gliomas.

Although not definitively proven, our data and previous studies suggest that NF-1-associated orbital optic nerve gliomas should not be treated unless there is clear evidence of either ophthalmologic or radiographic progression. Surgical excision of tumors which have led to proptotic eyes without functional vision should be reserved for cosmetic purposes or to treat complications of exposed globes.