Monitoring young children with optic pathway gliomas (OPGs) for visual deterioration can be difficult owing to age-related noncompliance. Optical coherence tomography (OCT
) measures of retinal nerve fiber layer (RNFL) thickness have been proposed as a surrogate marker of vision but this technique is also limited by patient cooperation. To determine whether measures of circumpapillary RNFL thickness, acquired with handheld OCT
) during sedation, can differentiate between young children with and without vision loss from OPGs.