Late-onset radiation-induced optic neuropathy after radiotherapy for nasopharyngeal carcinoma

Radiation-induced optic neuropathy (RION) is a rare but devastating late complication of radiotherapy, usually manifesting months to years after cancer treatment of the head and neck, resulting in rapidly progressive blindness in one or both eyes. The incidence of radiation-induced complications following radiotherapy, especially RION, is correlated with survival time of patients. Nasopharyngeal carcinoma (NPC), the most common type of cancer in southern China, has been primarily treated with radiotherapy, with associated neural injuries. To our knowledge, there are few reports of RION among patients with NPC who have undergone radiotherapy. To study this further, we reviewed nine patients with NPC and RION after radiotherapy and examined the clinical manifestations of RION, characteristics of the ophthalmologic examination, MRI results and the treatments used. Of the nine patients with RION, the most frequent clinical presentation was a decline of vision with visual field defects in one or both eyes. Ophthalmologic examinations showed flame hemorrhages in the retina, optic nerve atrophy and cotton wool spots. T1-weighted enhanced MRI showed enhancement of the optic nerve and optic chiasm in six patients. Treatment with corticosteroids, anticoagulation and hyperbaric oxygen (HBO) treatment did not reduce visual loss or blindness in patients.