A young man following RTA presented with proptosis and pain in the right eye after four days. On examination, there is a bruise on the forehead and right eye. What is the diagnosis -

Common causes of proptosis associated with craniofacial trauma are:- 1) Carotid-cavernous fistula ii) Retrobulbar hematoma iii) Superior orbital fissure and orbital apex syndrome Rare causes are:- Cavernous sinus thrombosis Subperiosteal hematoma So, amongst the given options carotico-cavernous fistula is the only common cause. Cavernous sinus thrombosis may also occur after trauma. But, trauma is a very rare cause of CST. It usually develops as complication of extension of infection from the adjacent sinus, teeth, ear, nose etc.