Abstract
Purpose
To report the case of a 25-year-old male who sustained significant ocular trauma from a confirmed foam round. To review the scientific literature on kinetic impact projectiles and legislation currently proposed to regulate their use.
Observations
A 25-year-old male presented to the emergency department with acute pain and vision loss in his left eye after being struck by a foam round. Initial exam showed significant periorbital ecchymosis, multiple eyelid lacerations, microhyphema, and vitreous hemorrhage. Computed tomography revealed fractures of the inferior and medial orbital walls. Optical coherence tomography also demonstrated full-thickness macular hole. Microhyphema resolved after 15 days with steroid and mydriatic drops. Vision at 60 days after injury stabilized at 20/60. Repeat OCT at this time revealed closure of the macular hole. Care for the patient is ongoing.
Conclusions and Importance
Foam rounds can cause a pattern of vision-threatening ocular trauma similar to that of rubber bullets with the additional risk of chemical injury. During the George Floyd protests, isolated reports of significant foam round-related ocular injuries have been reported in the press, but systematic epidemiologic and clinical data on the subject remains lacking. While accurate identification of the causative weapon is not required in the management of ocular trauma, it may impact advocacy efforts undertaken by physicians and the subsequent legislative efforts they inspire. Current state and federal law does not adequately protect individuals from these munitions. Multiple proposals in Congress aptly recognize the significant risk of blinding injury and mortality posed by all kinetic impact projectiles.
Introduction
Greater awareness of the significant ocular injuries and potential mortality associated with kinetic impact projectiles, such as rubber bullets and foam rounds, have mobilized efforts to ban these munitions from being used against civilian populations in the United States. However, the epidemiology and pattern of injury caused by foam rounds remain poorly understood.
Case report
A 25-year-old male with no previous medical history presented to the emergency department with acute vision loss and pain in the left eye after being struck by a projectile during a protest. He believed that he had been hit by a rubber bullet, but the projectile obtained by the patient was subsequently identified as a foam round ( Fig. 1 a). A green powdery substance was dispersed around the site of injury. At the time of presentation, he demonstrated an intact airway, breathing, and circulation and denied any history of recent alcohol or drug use. Vital signs at triage were within normal limits except for a reduced heart rate of 47.
On initial exam, the patient reported 10/10, stabbing pain in the left eye that worsened with downgaze. He also reported reduced vision in the left eye with photophobia, floaters, and photopsia. Examination of the right eye was within normal limits. The left eye demonstrated reduced vision at 20/50 with the near card. Intraocular pressure (IOP) was measured to be 14 mmHg by Tono-Pen. Pupil was round and reactive to light. The patient reported direct photophobia but denied consensual photophobia. Extraocular motility exam was significant for −2 inferior gaze restriction on the left side. pH testing was not performed.
Examination of the left adnexa revealed diffuse periorbital ecchymosis and edema. Two lacerations were noted: one 3-cm laceration on the upper eyelid and a 2-cm laceration located just inferior to the lower eyelid. Neither involved the eyelid margins or the canalicular system ( Fig. 1 b). A green pigment was found dispersed over the ocular surface and eyelids. The conjunctiva revealed diffuse 1+ injection with a localized subconjunctival hemorrhage temporally. The cornea was clear and without signs of ulceration or chemical injury. Examination of the anterior chamber demonstrated 4+ nonlayered RBC and an iris hemorrhage at 3 o’clock. Detailed dilated fundus exam was limited by significant microhyphema and patient discomfort.
Orbital CT revealed fractures involving both the inferior and medial walls of the left orbit and layering hemorrhage in the left maxillary sinus. No signs of an open globe were noted on imaging ( Fig. 2 ).
The green pigment was irrigated from the left eye with normal saline. Both eyelid lacerations were repaired. Treatment for the microhyphema was initiated with Pred Forte QID and tropicamide BID. The orbital fractures were managed conservatively, without surgical intervention.
The day after the injury, the patient’s vision had worsened to 20/300 in the left eye and improved with pinhole to 20/200. IOP remained within normal range at 17 mmHg. Pupils were reactive but now demonstrated posterior synechiae. Dilated fundus exam revealed inferior vitreous hemorrhage without signs of retinal tear or detachment. OCT revealed a full-thickness macular hole with cystoid macular edema ( Fig. 3 a). Frequency of Pred Forte was increased to once every hour, and consultation with the Retina Service was scheduled for management of the vitreous hemorrhage and macular hole.
The patient was examined again at three days post-injury. He reported improved pain, edema, and diplopia. Vision in the left eye was 20/200 with improvement to 20/100 with pinhole. No posterior synechiae was appreciated. The patient continued to have −1 inferior gaze restriction.
On the fifth day after injury, vision in the left eye improved to 20/50, and IOP remained stable at 14 mmHg. Forced ductions demonstrated full range of motion, and axial positions of the eyes, measured with a Hertel exophthalmometer, were 17 and 18 mm, respectively. Persistent binocular diplopia due to orbital inflammation was treated with oral steroids. With improvement in the microhyphema, Pred Forte was decreased to QID.
The patient continued to demonstrate progressive improvement in vision, diplopia, and pain at his subsequent four visits. IOP remained stable throughout. At his last visit (60 days after injury), his vision had stabilized to 20/60, with improvement to 20/50 with pinhole. IOP was 14. Vitreous hemorrhage showed signs of gradual resolution. Repeat OCT revealed closure of the full-thickness macular hole with nasal IS/OS drop out ( Fig. 3 b).
Care for the patient is ongoing.
Discussion
Kinetic impact projectiles (KIP) refer to a class of less-lethal munition designed to inflict pain and incapacitate individuals without penetration. There are many different types of KIPs, including rubber bullets and foam rounds, but all forms have been implicated in causing severe injury, permanent disability, and death.
The propensity of KIPs for causing significant ocular trauma is well-documented in the scientific literature. In 2017, a bean bag round, or flexible baton round, caused traumatic globe evisceration and basilar skull fracture. More recently, Ifantides et al. describe a case of globe rupture likely caused by a foam round during the 2020 George Floyd protests. A meta-analysis showed that 85% of all KIP-related ocular injuries globally resulted in permanent blindness. 3% of all KIP-related injuries resulted in death.
Foam or sponge rounds were designed for precision as a “point-of-aim, point-of-impact, direct-fire round.” The high velocity at which foam rounds are fired improves the accuracy of these rounds, but also exponentially increases the kinetic energy transmitted upon impact. Although the “foam” tip is designed to attenuate some of this energy, general recommendations suggest a minimum range of 32 feet (10 meters) and avoidance of vulnerable parts of the body, such as the head and torso. These rounds achieve even higher velocities in the closed position for extended range ( Table 1 ). The foam tip can be loaded with an array of irritant or marking payloads, as was observed in this case.
| Diameter | Weight | Velocity (Muzzle) | Recommended Range | Kinetic Energy (Muzzle) | |
|---|---|---|---|---|---|
| Anti-Riot Baton Round | 38 mm | 174 g | 60 m/s | 40 m to 100 m | 313 J |
| Rubber bullet, Northern Ireland, 1970 | |||||
| L2A1 Baton Round | 38 mm | 131 g | 63 m/s | 20 m–50 m | 260 J |
| Plastic Bullet | |||||
| Flexible Baton-12 Standard | 26 cm (fully deployed) | 100 g | 67 m/s | 15 m effective range | 160 J |
| Bean Bag Round | |||||
| Direct Impact® 40mm Adjustable Range Round, Marking Foam Round | 40 mm | 44 g | 82 m/s (opened) | 1.5 m–40 m (opened) | 147 J (opened) |
| 110 m/s (closed) | 40 m–70 m (closed) | 266 J (closed) |
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