Sporadic Optic Nerve Glioma Case Presenting with Unilateral Proptosis in a Child

Optic nerve gliomas (ONGs) are rare pediatric tumors of the anterior visual pathway, most commonly low-grade pilocytic astrocytomas. While frequently associated with neurofibromatosis type 1 (NF1) , sporadic cases tend to present later in childhood and may demonstrate a more aggressive clinical course. We report a case of a 12-year-old female who presented with sudden onset headache, progressive diminution of vision in the left eye, and unilateral proptosis of one week duration. Ocular examination revealed visual acuity of 6/6 in the right eye and counting fingers at 2 m in the left eye, with Grade 3 relative afferent pupillary defect, total color vision loss and optic disc edema. Hertel’s exophthalmometry confirmed left-sided proptosis. Neuroimaging showed a fusiform enlargement of the left optic nerve with optic canal widening on computed tomography, and T2 hyperintense, T1 hypointense lesion on magnetic resonance imaging without diffusion restriction, consistent with optic nerve glioma. There were no clinical features suggestive of NF1 . The patient was referred for neurosurgical evaluation and underwent 15 cycles of radiotherapy. This case highlights the importance of early recognition of sporadic optic nerve glioma as a cause of unilateral proptosis in children. Prompt ophthalmic assessment and neuroimaging are crucial to prevent irreversible visual loss and intracranial extension. Multidisciplinary management and long-term follow-up remain essential in optimizing outcomes.