Optical Coherence Tomography in the Diagnosis of Optic Pathway Gliomas

PURPOSE: To compare visual function assessment, optic disc evaluation by indirect ophthalmoscopy, and retinal nerve fiber layer analysis by optical coherence tomography (OCT) for the screening of optic pathway gliomas in pediatric patients (2-15 years old) affected by neurofibromatosis type 1. METHODS: Fifty-seven consecutive patients with neurofibromatosis type 1 with recent (<6 months) orbital/brain magnetic resonance images (MRI) were included. Patients underwent visual function assessment (Hyvarinen symbols chart and/or Snellen charts) and optic disc evaluation by indirect ophthalmoscopy performed by experienced, masked pediatric ophthalmologists. Spectral domain OCT was performed to assess retinal nerve fiber layer. RESULTS: Fifteen of 57 enrolled patients (26%) were affected by MRI-proven optic pathway gliomas. Visual function assessment, optic disc evaluation, and retinal nerve fiber layer analysis by OCT were feasible in 84%, 95%, and 88% of patients, respectively. Visual function assessment, retinal nerve fiber layer analysis, and optic disc evaluation results correlated with the presence of optic pathway gliomas (P = 0.007, P < 0.0001, and P = 0.03, respectively). Specificity and negative predictive value of each test were statistically significant in detecting optic pathway glioma (P < 0.0001), whereas only retinal nerve fiber layers analysis reached statistically significant sensitivity and positive predictive value (P = 0.0386). CONCLUSIONS: Retinal nerve fiber layer analysis assessment using spectral domain OCT is superior to visual function assessment and optic disc evaluation as a clinical screening tool for optic pathway gliomas.