Pictured above is a CT scan of my patient following a blunt force traumatic injury to the face. This CT scan slice, shown in the coronal plane, shows a Blow-Out type fracture of the right orbital floor where a significant portion of the orbital floor bone has descended into the maxillary sinus below.
Pure orbital floor fractures, referred to as isolated floor fractures, result from impact injury to the globe and upper eyelid. The offending object is usually large enough not to perforate the globe and small enough not to result in fracture of the orbital rim. Orbital floor fractures are secondary to a sudden increase in intraorbital hydraulic pressure. A high-velocity object that impacts the globe and upper eyelid transmits kinetic energy to the structures around the eye. This energy results in pressure with a downward momentum, heading toward the floor of the eye socket. Most fractures occur in the posterior medial region that is comprised of the thinnest bones.
After facial trauma, patients may describe any of a variety of symptoms: decreased visual acuity, blepharoptosis, double vision (especially in upgaze), and numbness (hypesthesia, dysesthesia, or hyperalgesia) in the distribution of the infraorbital nerve. This usually translates into numbness of the cheek below the eyelid, the side of the nose and the upper lip. In addition, patients may complain of nasal bleeding and eyelid swelling following nose blowing.
Periorbital ecchymosis and edema (bruising and swelling) accompanied by pain are obvious external signs and symptoms, respectively. Enophthalmos (“sunken in” eyeball) is possible but initially can be obscured by surrounding tissue swelling. This swelling can restrict ocular motility, giving the impression of soft tissue or inferior rectus entrapment. Bleeding in and around the eyeball can manifest with proptosis (or prominence/bulging) of the eyeball. A bony step-off of the orbital rim and point tenderness are also possible.