Optic-pathway glioma: natural history demonstrated by a new empirical score

The optic pathway glioma uniquely involves the optic pathway in a relatively constant pattern, allowing for recurrent measurements of its extent and comparison within patients with the same diagnosis. Its natural history, however, is unpredictable. We sought to formulate an empirical score to quantify optic-pathway involvement and disease course. The sample comprised 23 children with a diagnosis of optic-pathway glioma who attended a pediatric tertiary medical center from 1975-2004 and underwent at least two annual magnetic resonance imaging examinations over an average of 7 years. Each scan was evaluated for the larger diameters of intraorbital and retro-orbital parts of the optic nerve, chiasma, and optic tract. Findings were analyzed by time from diagnosis. In untreated children, tumors generally remained stable for about 3 years, and diminished thereafter. Children with neurofibromatosis-1 had a better course than children with sporadic disease. Young children fared similarly to older ones. Worse outcomes occurred in children who eventually required treatment; this group might have done better with earlier diagnosis, and requires careful follow-up. Our new empirical score can define the natural history of optic-pathway gliomas, and identify prognostic factors. It may help identify tumors in neurofibromatosis-1 children who potentially require treatment.