1. A 45-year-old man suffered penetrating trauma to his right orbit when a branch from a pine tree rebounded and entered his orbit through his protective helmet visor while snowmobiling. 2. He was transferred to New England Eye Center where imaging showed an intraorbital foreign body indenting his globe. He underwent surgery to remove the branch and irrigation of the wound tract. 3. By postoperative day five, his vision had improved and inflammation resolved, though he remained on antibiotics and steroids. Follow up showed excellent recovery of vision and motility.

1. New England Eye Center Grand Rounds Brendan E. McCarthy, M.D. April 12, 2001

2. New England Eye Center Grand Rounds Case Presentation: A 45 year-old Caucasian man was transferred from an out of state emergency room to the New England Eye Center for evaluation of penetrating trauma to the right medial orbit, with a retained foreign body. The patient was snowmobiling with friends, when he stopped his machine and walked ahead on a trail to break branches off a white pine tree ( Pinus strobus ), to allow for safe passage. (Figure 1) Upon breaking a branch there was rebound from the distal end of the branch which sent the branch up under the visor on his protective helmet.

3. New England Eye Center Grand Rounds The end of the branch had smaller, spoke-like projections (figure 2). As the branch entered the patient’s right medial orbit, one of the “spokes” broke off and the force knocked the patient to the ground. The patient was rushed to the emergency room were a local ophthalmologist examined the patient, and ordered an orbital computed tomography (CT) scan with axial and coronal views. The patient was instructed not to eat or drink, and was given a tetanus booster prior to transfer to New England Eye Center.

4. Figure 1 Photograph of the tree and branch involved

5. Figure 2 Close up of the distal end of the branch.

6. New England Eye Center Grand Rounds The patient’s past ocular history was significant for myopia and soft contact lens use. (The patient was wearing his contact lenses at the time of the injury, and the right lens was not seen after the trauma.) Past medical, family, and social histories were non-contributory. The patient took no regular medicines and was allergic to penicillin (=>hives/difficulty breathing) and meperidine (=>hypotension).

7. New England Eye Center Grand Rounds On examination, patient’s visual acuity with correction was 20/200 in the right eye with pin hole improvement to 20/100. The left eye was 20/70 with no pin hole improvement . The patient was pharmacologically dilated prior to his transfer; prior to dilation, no afferent pupillary defect was noted and the pupils were 5mm on the right and 2 mm on the left. A bulge was clearly visible beneath the medial aspect of the right upper lid. As the eye was opened, bare sclera was noted in the superonasal quadrant with a tree branch indenting the globe (figure 3). The right eye was seidel negative.

8. Figure 3 External Photograph

9. New England Eye Center Grand Rounds Intraocular pressures were 22 mm Hg on the right and 12 mmHg on the left. Extraocular movements of the right eye were less than 10 percent in all directions of gaze, and full in the left eye. Examination of the left eye was normal. The anterior segment examination of the right eye revealed multiple pupillary sphincter tears, iris stromal hemorrhage, and transillumination defects. A microhyphema was also present. The lens was clear and the anterior vitreous was quiet.

10. New England Eye Center Grand Rounds Dilated fundus examination on the right revealed a normal disk, macula, and vessels. In the superonasal quadrant, there was a small area of intraretinal hemorrhage over an area where the globe was indented from the orbital foreign body. CT scans (figure 4) revealed an intraorbital foreign body isodense with air, extending from the medial upper lid toward the orbital apex. The globe was indented and displaced inferotemporally. The orbital bones were completely intact, without any fractures.

11. Figure 4 CT scan of the right orbit

12. New England Eye Center Grand Rounds After discussion with the Eye Plastics and Orbit Service, the patient underwent surgical exploration and removal of the foreign body. Infectious Disease was consulted regarding choice of antibiotic and timing of oral prednisone. The patient was brought to the operating room and given general anesthesia and intravenous vancomycin and gentamicin.

13. New England Eye Center Grand Rounds The right lid was gently retracted, revealing a portion of the tree branch protruding from the superonasal quadrant of the orbit (figure 5). The branch was grasped with forceps and gently delivered out of the orbit without further trauma to the globe or surrounding tissues (figure 6). The patient’s contact lens was located at the tip of the branch (figure 7). One other piece of the contact lens was located in the orbit upon further exploration.

14. Figure 5 View of branch after lifting the right lid.

15. Figure 6 Delivery of the branch

16. Figure 7 Contact lens as it was found on the internal end of the branch.

17. New England Eye Center Grand Rounds The wound tract was the irrigated with a dilute gentamicin solution, and pieces of bark were removed from the wound tract. The wound was explored and residual foreign material was removed. The wound tract was left open to drain, and no sutures were placed. Homatropine drops twice a day were started, and erythromycin ointment was placed on the eye. The eye was then covered with a shield. The specimens were sent to pathology for examination. Inflamation was present, as well as spores and non septated hyphe (figures 8 and 9).

18. Figure 8 Gross, cross section, and microscopic sections of the branch.

19. Figure 9 H&E, and GMS staining of the branch bark.

20. New England Eye Center Grand Rounds Late on post operative day one, an oral prednisone taper starting at 80 mg and decreasing by 10 mg per day was instituted. Prednisolone acetate drops every two hours, and brimonidine twice daily was started in the right eye. Antibiotics recommended by the Infectious Disease Service were intravenous vancomycin and amikacin, and oral metronidazole. Prophylactic antifungal treatment was not initiated at this time per recommendation of the Infectious Disease Service By post operative day two, the patient’s visual acuity had improved to 20/70.

21. New England Eye Center Grand Rounds By postoperative day five, the patient’s best corrected visual acuity was 20/25 in the right eye and the microhyphema had resolved. Dilated fundus examination revealed resolution of the retinal hemorrhages (Figure 10). Intraocular pressure in the right eye was 16 mmHg. The patient was examined by the Retina and Glaucoma services and was discharged on postoperative day eight.

22. Figure 10 Fundus photographs of the right and left eyes.

23. New England Eye Center Grand Rounds Follow up examination by the Eye Plastics and Orbit Service revealed excellent motility and stable visual acuity (figure 11). The patient was referred back to his local ophthalmologist and follow up with the New England Eye Center is pending.

24. Figure 11 External photographs of the right and left eyes.

25. New England Eye Center Grand Rounds Discussion: This case represents penetrating orbital trauma to the right medial orbit. The patient’s initial post operative recovery period has been surprisingly uncomplicated, given the nature of the injury. Orbital inflammation and infection are important risks of this type of injury. Damage from blunt trauma as in this case may also lead to problems with glaucoma, and a variety of other serious eye problems.

26. New England Eye Center Grand Rounds Trauma is the most common cause of monocular blindness. There is a strong male preponderance (approximately 80%), with a disproportionate number of injuries in the young adult population. Approximately half of all serious eye injuries occur in occupational settings, while one third of serious eye injuries occur in sports, and children at play. The vast majority of those sustaining serious eye injury do not have protective eye equipment on at the time of injury.

27. New England Eye Center Grand Rounds Thus, serious eye injuries continue to be a major source of preventable disability. The use of protective eyewear in occupational settings and sports activities is the best defense against serious eye injury.

28. New England Eye Center Grand Rounds References: Grove AS Jr. Computed tomography in the management of orbital trauma. Ophthalmology 1982. 89:433-440 Johnson TE. Intraorbital branch. Arch Ophthalmol. 2000 118(4):590-591 Nasr AM, Haik BG, Fleming JC, et al. Penetrating orbital injury with organic foreign bodies. Ophthalmology. 1999. 106 (3):523-532

29. New England Eye Center Grand Rounds References: Specht CS, Varga JH, Jalali MM, et al. Orbitocranial wooden foreign body diagnosed by magnetic resonance imaging can be isodense with air and orbital fat by computed tomography. Surv Ophthalmol. 1992. 36 (5): 341-344 Nessi FA, Lisman RD, Levin MR. Ophthalmic and Plastic Reconstructive Surgery. St Louis, 1998 Mosby Year Book Inc 3-73.

30. New England Eye Center Grand Rounds References: Schein OD, Hibberd PL, Shingleton BJ, et al, The spectrum and burden of ocular injury. Ophthalmology 95:3 1988 300-305