(See also Overview of Eye Injuries.)
Fractures of the floor (bottom) of the orbit (blowout fractures) are common, but fractures of other parts of the orbit also occur. Occasionally, the eyeball itself also is damaged.
Sometimes the eye is struck in such a way that the force of the blow is received by the eyeball and not blocked by the strong bones around the eye (as when struck by a small object such as a golf ball or a fist). In this case, the pressure on the eyeball is transmitted to the walls of the orbit. This pressure can fracture one of the most fragile parts of the orbit, the part underneath the eyeball (orbital floor). Direct blows to the face can also transmit forces causing the same fracture. These types of injuries are known as blowout fractures. Sometimes parts within the eye socket, such as a muscle attached to the eye, are forced through the fractured bone and become trapped—this happens most often in teens and young adults and requires urgent repair.
Blowout fractures sometimes cause double vision, a sunken eyeball (particularly once the swelling resolves), an eyeball that is lower in the face, a decreased sensitivity to touch and pain around the cheek and upper lip (caused by injury to the nerves below the orbit), or an accumulation of air and/or blood in the tissues under the skin (subcutaneous emphysema and ecchymosis). Double vision can occur because the eye is severely swollen or if one of the muscles that move the eye is trapped in the fracture. The trapped muscle, usually the muscle that moves the eye down (the inferior rectus), prevents the eye from aiming itself at the object the other eye is looking at. Subcutaneous emphysema occurs if a fracture of the orbital floor allows air from the nose or sinuses to enter the tissues around the eye, particularly when people blow their nose. Bleeding can also occur in the eye socket (orbital hemorrhage) or the eyelids. Rarely, an increase in air or blood within the eye socket can lead to very high pressure of the eyeball, which must be addressed urgently.
Some patients with a fracture of the orbit have no symptoms. However, most fractures of the orbit are painful, and the area swells because blood and fluid accumulate. The accumulated blood usually causes the swollen area to appear blue or purple (a black eye). Sometimes the nose bleeds.
Vision may be impaired if the eyelids are swollen shut, or on rare occasions if the eyeball is damaged or if blood from torn blood vessels accumulates behind the eyeball (retrobulbar hematoma) and puts pressure on the nerve leading to the brain (optic nerve).
Diagnosis of an orbital fracture is suspected based on the symptoms and results of a physical examination. A doctor who suspects an orbital fracture does computed tomography (CT), which shows any fractures, collections of blood, and displaced or trapped tissue. A full eye exam is also performed on both eyes to assure there are no other injuries.
People who have an orbital fracture should avoid blowing their nose, which may cause swelling if the air they blow out collects under the skin around the eye. Using a nasal spray that constricts blood vessels (topical vasoconstrictor) for 2 to 3 days may help minimize nosebleeds. Applying ice as for other fractures and injuries can help decrease pain and swelling. Keeping the head elevated above the level of the heart may also help prevent further swelling. Analgesics can help control pain. Antibiotics can be used if an infection develops.
Surgical repair of the facial bones is necessary if a blowout fracture traps muscles or soft tissues of the orbit and causes double vision. It can also be considered if the fracture is large or the eyeball sunken. After ensuring that the fracture has not damaged a vital structure, the surgeon uses implants, a thin plastic sheet, or a bone graft to connect the broken parts and assist healing, and releases any muscle or other trapped orbital tissue.