phuluong2k
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Exam, do you have the answer ? plz post it for us
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| LisaM
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Blow-out fracture to the orbit can either be 'pure'- not involving orbital rim or 'impure'- involve orbital rim and adjacent facial bones. It is typically caused by sudden increase in orbital pressure by a striking object >5cm in diameter such a fist or a tennis ball. The lateral wall and roof are able to withstand the pressure rise. Blow-out fracture commonly involves the floor of the orbit but medial orbital wall may also be fractured.
Clinical features vary according to the severity of the trauma and time interval between fracture and examination.
periocular signs:
variable acchymosis and edema.
Infraorbital nerve anesthesia:
Involves lower lid, cheek, side of nose, upper lip, upper teeth and gums when the blow-out fracture begins along the medial side of the infraorbital canal and extends nasally.
Diplopia:
May be caused by
1. Hemorrhage and edema of orbital fat: cause the septa which connects the inferior orbital and inferior rectus muscles to become taut and restrict movements of the globe. Ocular motility improves as hemorrhage and edema are absorbed.
2. Mechanical entrapment of inferior rectus of inferior oblique or adjacent connective tissue or fat. The diplopia typically occurs in both upgaze and downgaze. The diplopia improves if it is caused by entrapment of connective tissue of fat wtihin the fracture but persists if it is due to entrapment of muscle.
3. Direct injury to muscle. The muscle fibers regenerate and normal function returns in two months.
Intraocular hemorrhage:
Hyphema, angle recession and retinal dialysis are uncommon but may occur.
Enophthalmos:
May be present if the fracture is severe. In the absence of surgical intervention, the enophthalmos continues to worsen for about 6 months as post-traumatic orbital degeneration and fibrosis develop.
(from Clinical Ophthalmology, Jack J. Kanski)
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lisa
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| yasmeen
Forum Guru
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B IS RIGHT
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| krsna
Forum Senior
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does the q mention about the degree of injury or the timing?
first thing i think shud be enopthalmus
diplopia however can be a late development
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