Abstract: Tumors of the head and neck are often located adjacent to visual pathways. Radiotherapy is an indispensable treatment for these tumors, but it also carries a significant risk of severe delayed visual impairment. Radiation-induced optic neuropathy (RION) is a delayed, radiation-induced ischemic injury of the optic nerve and optic chiasm, characterized by acute or subacute painless vision loss that can lead to irreversible visual impairment. The latency period ranges from several months to years. The incidence of RION is closely associated with radiotherapy techniques and doses, varying among different tumor types. The pathogenesis of RION remains incompletely elucidated but is thought to involve vascular endothelial damage-induced ischemia and edema, as well as axoplasmic transport disruption in the optic nerve fibers. Diagnosis of RION is primarily one of exclusion, requiring the exclusion of other causes of vision loss, such as tumor recurrence, followed by a comprehensive analysis of medical history, clinical manifestations, and imaging findings. Current treatments for RION are mainly symptomatic, as no definitive cure exists. Options include corticosteroid therapy, hyperbaric oxygen therapy, and anti-vascular endothelial growth factor (anti-VEGF) therapy. This review aims to systematically elaborate on the concept, epidemiological characteristics, influencing factors, clinical manifestations, diagnosis, and treatment of RION, providing a reference for clinical decision-making in radiotherapy for head and neck tumors and the prevention and management of RION.

Key words: Radiation-induced optic neuropathy, Head and neck tumors