Spontaneous resolution of choroidal neovascular membrane in the fellow eye during hyperbaric oxygen treatment for retinal artery occlusion: a case report

Retinal artery occlusion (RAO) is an ophthalmic emergency that causes sudden, painless vision loss due to retinal ischaemia. Hyperbaric oxygen therapy (HBOT), when initiated early, may help preserve photoreceptor function by increasing retinal oxygenation. A 69-year-old woman with a history of hypertension presented with sudden visual loss in the left eye and was diagnosed with RAO. HBOT was initiated within six hours of symptom onset (253 kPa [2.5 atmospheres absolute] for 90 minutes per session), and 20 sessions were planned. During the seventh session, the patient reported a marked improvement in visual acuity in the contralateral (right) eye, previously diagnosed with choroidal neovascular membrane (CNVM) and untreated with anti-vascular endothelial growth factor (VEGF) therapy. Optical coherence tomography demonstrated regression of the CNVM and complete resolution of subretinal fluid. To our knowledge, this is the first report suggesting that HBOT administered for unilateral RAO may also promote structural and functional improvement of CNVM in the contralateral eye.