<prompt> Blow out fracture of orbit is characterized by all EXCEPT:Orbital floor and medial wall involvement are commonTear drop sign on X-RayDiplopiaExophthalmos  <response>: Ans. d ExophthalmosRef: A.K. Khurana 6th ed. 1422-23, Khuranas 4th Ed.g 397-398 Blowout fractures mainly involve orbital floor and medial wall. It usually result from trauma to the oribit by a relatively large, often rounded object, such as tennis ball, cricket ball etc. With a resultant fracture of the weakest point of the orbital wall.Classification Pure blow-out fractures: Not associated with involvement of the orbital rim. Impure blow-out fractures: Associated with other fractures about the middle third of the facial skeleton.Clinical Feature Periorbital oedema and blood extravasation in and around the orbit Emphysema of the eyelids occurs more frequently with medial wall than floor fractures. Paraesthesia and anaesthesia Ipsilateral epistaxis Proptosis and Ptosis Enophthalmos; NOT Exophthalmos Diplopia Plain x-rays Waters view: fragmentation and irregularity of the orbital floor; depression of bony fragments and hanging droptear drop opacity of the superior maxillary antrum from orbital contents herniating through the floor. 