Penetrating orbital wounds with a wooden foreign body are uncommon. Only a few cases and small series have been reported. Although diagnostic imaging has greatly improved in the past few decades, an accurate history and clinical and laboratory findings are still of great importance in this rype of injury, especially when deciding which type of imaging to employ, when to use it, and how to interpret the findings.
A 10-year-old boy was brought to the emergency department with an injury to his right upper eyelid. He had fallen on a metal wire. On examination, he had a 2-cm, horizontal, deep laceration in the nasal aspect of the right upper eyelid, with no visible foreign body. Ocular movements were normal. Best-corrected visual acuity of the right eye was 6/60, with normal results on ocular examination except for a possible dilated pupil considered traumatic. Results of an examination of the left eye were normal with a visual acuity of 6/6. The initial diagnosis was traumatic mydriasis of the right eye with laceration of the uppet eyelid. The laceration was sutured. Hc was given an intramuscular injection of tetanus toxoid and released.
Figure 1. (Top left) Primary gaze proptosis with temporal and down deviation of the right eye, (top righi) righi gaze, (bottom left) left and down gaze, and bottom right) up gaze.
One day later, the boy returned to the emergency department complaining of increasing pain and swelling at the site of injury. The right eyelids and surrounding soft tissues were markedly swollen with purulent discharge exuding from the sutured wound. He exhibited mild proptosis, temporal and down deviation of the eye, and near total ophthalmoplegia (Fig. 1). The visual acuity was reduced to hand movements. Results of die remainder of the ocular examination, other than a dilated pupil and significant chemosis, were normal, including a fundus examination.
Right orbital cell ulitis was diagnosed. The sutures in the wound were removed and a large amount of malodorous pus with gas bubbles burst forth from the orbit. Ditect Gram stain and cultures demonstrated gram -negati ve rods, g ram -pò sit i ve rods, and possible Candida. He was given intravenous anioxicillin- c! avulanate and cloxacillin. An orbital computed tomography (CT) scan demonstrated an extraconal infiltration with air along the length of the medial rectus muscle, causing temporal and down deviation of the globe (Fig. 2}. There was suspected fracture of the lamina papyracea with definite infiltration of the right maxillary and ethmoidal sinuses.
The next day, the patient's visual acuity dropped to no light perception. He underwent an emergency surgical exploration of the wound, which revealed a deeply buried, fragile, wooden foreign body measuring approximately 3 X I X 0.5 cm.
On repeated CT scan 1 day later, no "residual air" was seen, but the medial orbital infiltration remained. On this study, the lamina papyracea appeared intact, but the right optic nerve was thickened with hypodense areas. Magnetic resonance imaging (MRI) of the orbit was unremarkable. Culture revealed Clostridium perfringens and Escherichia vulneris with no fungal growth. The antibiotic treatment was changed to cefuroxime and clindamycin with concern for the possibility of osteomyelitis developing in the infected area. Systemic steroids were added to the antibiotic regimen. During the next few days, the pain, swelling, and inflammation in the wound area improved, but the patient's visual acuity remained no light perception. Visually evoked potentials recorded no response from the right eye, but a normal response from the left eye.
The patient was discharged with oral amoxicillin- clavulanate treatment for 1 month. On outpatient clinic follow-up, his ocular movements gradually returned to normal, whereas his right optic nerve developed severe pallor. He remained totally blind in this eye.
As shown by a literature review, die clinical presentation of an orbital wooden foreign body can be variable and misleading. Early signs that should lead to suspicion of a foreign body include disturbances of visual function,1 an orbital vessel erosion with recurrent bleeding, persistent bleeding, or both,2'3 severe infection with sinus or brain involvement,4 and ocular motility abnormalities, proptosis, and pain.2·5'6
Arriving at the correct diagnosis of orbital wooden foreign body may be difficult. The patient's history may be misleading5; in our case, we were told of a metal wire injury. Penetrating orbital wounds may be difficult to evaluate clinically, and are usually underestimated. An intraorbitai wooden foreign body from a seemingly trivial penetrating wound can lead to disastrous sequelae for the eye, the orbital contents, and even the brain.4'5
Radiographie studies and CT may fail to identify an orbital wooden foreign body. Success in detection of wood by CT depends on the degree of wood hydration, incorporation of a radiopaque substance, the location of the wood and the extent of collateral inflammation, and, most importantly, a high index of suspicion by the physician.1·7 In some cases, a wooden foreign body was misinterpreted initially as air,'·7 as in our case. Standardized ultrasound (combined standardized A scan and B scan ultrasound) may be diagnostic in some cases, but its value is limited by availability and the experience of the sonographer.8 MRJ is considered the best diagnostic study, but it is not always available when needed, is costly, and must be performed under general anesthesia in children.9 In an experimental model of intraorbitai wooden foreign body, MRI was superior to CT in finding pieces of wood as small as 3 mm, detected by relative hypointensity, but the degree of intensity can be influenced by the type of wood and the time period from the injury.10,11
Figure 2. Computed tomography scan showing right orbital infiltration with air.
The wooden foreign body may be asymptomatic initially or may exhibit subacute ot chronic symptoms, such as proptosis or limitation of movement.6 In one chronic case, a wooden foreign body was found during excision of a presumed "melanoma."2
An intraorbitai foreign body should be suspected in any patient sustaining even minor eyelid trauma, especially if there is a history of injury by a sharp object.1 An important finding is that of fat at the wound. This indicates violation of die orbital septum and obligates the physician to rule out a foreign body.1·6 Unexplained visual loss with an intact eye, severe acute infection (especially with C. tetani),7 restricted ocular motility, or proptosis should also alert the physician to the possibility of a wooden foreign body, especially if the routine orbital roemgenogram is negative or if a streak of air is reported on CT. li7 MRI or ultrasound should be ordered if the diagnosis is not clear, especially if the patient's condition deteriorates. In our case, the initial reduced visual acuity with the dilated pupil and intact eye should have alerted us to die possibility of traumatic optic neuropathy and the necessity for a more thorough investigation. Fulminant orbital infection accompanied by die air seen on CT indicates an intraorbital foreign body unless proven otherwise. In our case, a later reinterpretation showed that die streak of air extended to die level of the optic nerve proximally. His visual loss could then be explained by direct laceration of this structure, aggravated by die infection and edema.
Once the foreign body is diagnosed, precise localization should be ascertained to plan the optimal surgical approach and to evaluate the status of the surrounding structures. Consultation and collaboration with an ear, nose, and throat specialist is often helpful. Blind intraorbital exploration should be discouraged, although in our case this became necessary because of the rapid downhill course. After extraction of a foreign body, the infected and inflamed wound should be treated with broad-spectrum systemic antibiotics and steroids.
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