Utility of optic pathway glioma screening in young children with neurofibromatosis type I: questions generated by a clinical audit.

AIM: Neurofibromatosis type I (NFI) is a phakomatosis that affects approximately 1 per 3000 live births. About 15% children with NFI develop optic pathway glioma (OPG). The Neurofibromatosis UK society recommend annual ophthalmic screening to identify those children who may have OPG affecting vision and refer for investigation and treatment as necessary. METHODS: We undertook a retrospective audit with three aims: (1) to elicit if departmental screening practice of children with NFI for OPG meets current guidelines, (2) to document the age at which tests of visual function are useful in the diagnosis and screening of OPG, and (3) to document the contribution eye screening has made to the diagnosis of OPG. RESULTS: A total of 37 children were identified from the clinic register. Overall 43% children met the criterion for an appropriate number of screening episodes. All the children met the visual acuity and optic disc assessment criteria; 84% met the pupil-testing criterion. No child was mature enough to perform visual fields or colour vision testing. CONCLUSION: Further education is required to encourage patients to attend eye clinic for screening as the majority of patients failing to reach the standard were due to non-attendances. No OPGs were detected during 128 screening episodes over approximately 7 years of screening. The authors question the usefulness of including visual field and colour vision assessment in the protocol for this age group.