Hyperbaric oxygen therapy in the treatment of radiation optic neuropathy.

Radiation optic neuropathy (RON) is characterized by the rapid onset of painless irreversible vision loss in one or both eyes. We report 4 consecutive patients who presented with unilateral or asymmetric bilateral RON. All had bilateral optic nerve enhancement on MRI and were treated with hyperbaric oxygen (HBO) and oral corticosteroids. In the less affected eye, 2 of the 4 patients had preservation of vision, while in the other 2 patients, vision declined. No patient showed improvement in the more symptomatic eye, and in 2 patients, there was a significant decline in visual acuity. Our findings suggest that prompt treatment with HBO and oral corticosteroids may result in visual preservation in the less affected eye despite the presence of optic nerve enhancement on MRI.