Unilateral blindness after orthognathic surgery: hypotensive anaesthesia is not the primary cause.

Perioperative vision loss in non-ocular surgery represents a rare but devastating complication and multiple causes have been proposed. Any portion of the visual system may be involved and several authors have tried to relate that complication with deliberate hypotension anaesthetic technique, used to control intraoperative bleeding. We report a patient operated for orthognathism who suffered unilateral blindness. After review of similar cases, we can state that the transmission of forces generated during Le fort I osteotomy is related to the complication. This osteotomy technique is regularly performed in our hospital using a curved osteotome to achieve the pterygomaxillary disjunction and the adverse transmission of forces via the sphenoid bone is the main reason for indirect damage to the optic nerve and its vascular structures causing the neuropathy and blindness. Hypotensive anaesthesia may certainly lead to transient ischaemia but only in specific cases because of decreased ocular perfusion pressured.