Visual Outcomes after Chemotherapy for Optic Pathway Glioma in Children with and without Neurofibromatosis Type 1: Results of the International Society of Paediatric Oncology (SIOP) Low-Grade Glioma 2004 Trial United Kingdom (UK) Cohort
Kevin M. Falzon, MD, FRCOPHTH; Evangelos Drimtzias, MD, PhD; Susan Picton, FRCP; Ian Simmons, FRCOPHTH
Leeds Children’s Hospital
Introduction: To report visual acuity (VA) outcomes following chemotherapy for optic pathway glioma (OPG) in children with or without neurofibromatosis type-1 (NF1) and to analyse associated risk factors.
Methods: A prospective, multi-center, cohort study including 155 children treated between September 2004 and December 2012. Initial and final VA was used for per-eye and per-subject analysis. Correlation tests were performed to determine whether initial VA predicted final VA. Logistic regression was used to determine whether age and tumor location were associated risk factors.
Results: 90 children had complete ophthalmological data. At initiation of chemotherapy, 26% and 49% of eyes with NF1-OPG and sporadic-OPG respectively had VA of >/=0.7 LogMAR. At final visit, per-eye, 49% had </=0.2, 23% had 0.30-0.60 and 28% had VA >/=0.70 LogMAR in the NF1-OPG group. In the sporadic-OPG group, per-eye, 32% had </=0.2, 11% had VA 0.30-0.60 and 57% had >/=0.70 LogMAR. Children with sporadic-OPG, per-eye, were significantly less likely to have VA outcomes </=0.60 LogMAR compared with children with NF1-OPG (OR=0.30; 95% CI= 0.16-0.56; p<0.0001). Per-subject, VA improved in 24%, remained stable in 35% and worsened in 41% of children with NF1-OPG and improved in 18%, remained stable in 43%, and worsened in 39% of children with sporadic-OPG.
Discussion: Initial VA predicts final VA outcome. Younger age, post-chiasm tumor location and sporadic tumors were associated with unfavourable VA outcomes. MRI outcomes correlate poorly with VA outcomes.
Conclusion: Children with and without NF1 demonstrated the same rate of VA improvement, stabilization or worsening, however, children with sporadic-OPG had a poorer VA outcome.
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2. Wan MJ, Ullrich NJ, Manley PE et al. Long-term visual outcomes of optic pathway gliomas in pediatric patients without neurofibromatosis type 1. J Neurooncol 2016 129: 173.
3. Kelly JP, Leary S, Khanna P, Weiss AH. Longitudinal measures of visual function, tumor volume, and prediction of visual outcomes after treatment of optic pathway gliomas. Ophthalmology. 2012 Jun;119(6):1231-7.