Penetrating orbital injuries from plant material during pond and river diving.

Diving into lakes and ponds is a common activity of rural children. We present two cases of penetrating orbital injuries from plant matter sustained in this manner. Such injuries pose a particular challenge because wooden foreign bodies are often missed during orbital exploration, and current imaging modalities cannot reliably identify retained organic material. When a patient presents with orbital penetration after a high-risk mechanism of injury, such as freshwater diving, the clinician must maintain a very high index of suspicion for retained wooden foreign body.

According to most previous reports, manmade objects are the most commonly described cause of penetrating orbital injuries sustained during sports and recreation.[1] However, another source of penetrating orbital injury is plant matter that grows in the shallow waters of rivers and ponds. As diving is a common pastime of children in rural areas, these injuries are a cause for considerable concern. Further more, imaging studies often do not clearly identify retained wooden foreign bodies, making them especially dangerous.[2-6]

We report two cases of penetrating ocular injury from plant materials sustained during pond and river-diving. To our knowledge, this particular type and mechanism of injury has only been described once before and has not yet been fully recognized as a preventable cause of injury.[7] We describe the process of diagnosis, treatment, and visual outcome for each child.

Case Reports

Case 1

A 6-year-old boy presented with a history of penetrating injury to the upper left eyelid sustained while diving head-first into a pond. On presentation, he could only perceive hand movements very close to his face. Since a computed tomography (CT) scan done at this time did not reveal the presence of any foreign body, the patient was treated for orbital cellulitis. One month later, he returned reporting discharge from the eyelid wound, which had formed a fistula. He also had unresolved proptosis and lid edema. A repeat CT scan showed an abscess with an empty sinus tract but no distinguishable foreign body [Fig. 1]. The patient subsequently developed septic arthritis of the left hip joint, which was treated separately. Subsequent re-evaluation of the patient's left eye revealed a queried perception of light, relative afferent pupillary defect, optic disc pallor, and inferotemporal displacement of the globe. A superonasal quadrant granulation mass was observed from the non-healing wound, but elevation and depression of the globe in adduction were minimally restricted. Re-evaluation of the CT scan showed a single hypodense superomedial lesion corresponding to the previously noted sinus tract. A superomedial orbitotomy resulted in the removal of 4 wooden foreign bodies, each approximately 1.5 inches in length. By post-operative day 5, the patient's edema and proptosis had resolved. At 1-month follow-up, the eyelid wound was completely healed, and left eye visual acuity had improved to 20/120.

Figure 1

Axial (a) and coronal (b) CT of a 6-year-old boy with a history of penetrating injury shows an empty abscess tract without obvious foreign body. Further review reveals a single hypodense lesion (c). Subsequent orbitotomy recovers four wooden fragments (d)

Case 2

A 12-year-old boy presented to an outside hospital with fever, vomiting, and a prominent right eye with a painful, swollen lower lid. He had a history of a penetrating injury sustained while diving head-first into a river 12 days previously. Visual acuity in the right eye was 20/40. He was diagnosed with orbital cellulitis after initial CT scans showed only orbital edema. An orbital exploration revealed an accumulation of pus, but no foreign bodies. After 1 week of treatment with systemic antibiotics, the patient presented to our institution with continued swelling at the injury site. He had an indurated swelling of the lower lid with a discharging sinus, mechanical ptosis, diplopia, eccentric upward displacement of the globe, and 3-mm of proptosis. Adduction and depression were restricted. Repeat CT scan showed a hypodense body surrounded by secondary granulomatous inflammation [Fig. 2]. Subsequent exploration recovered a 2-inch wooden foreign body from the right inferomedial orbit. Post-operatively, the patient showed symptomatic improvement with a reduction in proptosis and a visual acuity of 20/30 in the affected eye [Fig. 3].

Figure 2

Coronal (a) and axial (b) CT scans taken one week after initial CT showed no evidence of retained foreign body. CT now shows a hypodense body surrounded by secondary granulomatous inflammation

Figure 3

Pre-operative (a) and post-operative (b) photographs of 12-year-old boy with a history of penetrating injury by a 2 inch wooden foreign body (c) sustained while pond-diving

Discussion

The injuries sustained in the cases we present are troubling since swimming and diving in rivers, ponds, and other natural bodies of water is a common pastime of children in rural areas worldwide. Penetration injuries by wooden foreign bodies embedded in shallow riverbeds have not been previously recognized as a risk of outdoor swimming and diving. However, in our experience these types of injuries represent a true threat to vision.

This danger is compounded by the fact that retained organic foreign bodies are not often immediately apparent on imaging studies, making prompt removal difficult. Previous studies report that wood, depending on its level of hydration, can be isodense to either air or orbital fat on CT scan.[23] In our two cases, CT scans taken within a few days of injury did not show a distinct foreign body, but only edema and signs of inflammation. Only after the foreign body became infected did a discharging sinus cavity form and become evident on CT scans. While Nasr et al. found magnetic resonance imaging (MRI) to be slightly better at identifying organic foreign bodies,[2] other studies recommend using CT scans for the initial identification of wooden foreign bodies, so the best imaging method remains controversial.[35] As in our case, serial imaging in patients with a high-risk mechanism of injury may be a useful non-invasive method of identifying a retained wooden orbital foreign body.[6]

Unfortunately, orbital exploration does not always identify the presence of a wooden orbital foreign body.[48] As in our two cases, these fragments are often not lodged in a tissue, but embedded within orbital fat. They are thus mobile within the orbital cavity until becoming enclosed within a discharging sinus. Thus, even after a negative orbital exploration, it is important to keep a high index of suspicion for a retained wooden orbital foreign body.

In summary, ophthalmologists attending to cases of penetrating orbital injuries sustained during river and pond diving should maintain a high index of suspicion for a retained wooden orbital foreign body and realize that neither orbital exploration nor imaging may be sufficient for diagnosis. Consideration should be given to serial imaging in the event of a negative initial scan. A thorough history as to the mechanism of injury, a meticulous exam, and frequent follow-up visits are also of utmost importance.