The most effective method for the screening and monitoring of optic pathway gliomas in children with neurofibromatosis type I remains a dilemma, Children less than 6 years of age are the group at highest risk for the development of optic pathway gliomas, Although an annual ophthalmologic examination currently is recommended as the most efficient method to screen for optic pathway gliomas, this method is often unreliable and inaccurate in young children. Magnetic resonance imaging remains the most sensitive test; however, cost and the need for sedation or general anaesthetic preclude its use as a routine screening test. We previously have recommended visual-evoked potentials (VEPs) as a possible alternative or aid in the assessment of optic pathway gliomas in this group of patients. The aims of this study were to ascertain the sensitivity of VEPs in detecting optic pathway gliomas and to determine whether VEPs are useful in monitoring the progress of optic pathway gliomas, This study provides further evidence of the sensitivity of VEPs in detecting optic pathway gliomas, In addition, VEPs may provide additional useful information concerning the progression of optic pathway gliomas once they have been detected. (C) 2001 by Elsevier Science Inc. All rights reserved,