Orbital haemorrhage and prolonged blindness: a treatable posterior optic neuropathy.

Two patients developed traumatic orbital haemorrhage resulting in prolonged blindness. Orbital decompression successfully reversed the visual loss, though both eyes had no light perception for at least 3 1/2 hours. The clinical findings suggest damage to the posterior optic nerve as cause of the visual loss. The optic nerve tolerance time to ischaemic injury may be longer than previously thought.