This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Orbit, Subject name: Ophthalmology
[{'content': 'Blow out fracture of orbit is characterized by all EXCEPT: \nSelect and explain. \nA. Orbital floor and medial wall involvement are common, B. Tear drop sign on X-Ray, C. Diplopia, D. Exophthalmos', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. (d) ExophthalmosRef: A.K. Khurana 6th ed. 1422-23, Khurana's 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 drop/tear drop* opacity of the superior maxillary antrum from orbital contents herniating through the floor.", 'role': 'assistant'}]