[Temporary blindness after transnasal ethmoidectomy (author's transl)].

A unilateral blindness after transnasal ethmoidectomy was diagnosed postoperatively while the patient was still in theatre. Exploration via an external approach was performed immediately, a haematoma was drained and the posteroir ethmoid artery was cauterized. This led to a recovery of vision. The temporary blindness was probably due to increased intraorbital pressure by the retrobulbar haematoma which led to stretching of and pressure on the optic nerve.