Diffuse retinal injury from a non-penetrating TASER dart

Abstract

To describe a non-penetrating TASER gun injury resulting in a small exudative retinal detachment but significant visual acuity and retinal function loss as demonstrated by electroretinography (ERG). A 39-year-old man presented to the emergency department with a TASER barb embedded in his right lower lid. A complete clinical ophthalmologic examination and surgical extrication were performed, as well as radiologic imaging and Ganzfeld electroretinography. No scleral penetration was observed on surgical exploration. Retinal examination showed a peripheral exudative detachment. Subsequent follow-up revealed progressive resolution of the detachment and improvement in visual acuity. The ERG showed a 63-70% decrease in rod a- and b-waves, while isolated cone responses were reduced by only 10%, with a minimal increase in implicit time. This case shows that periocular TASER injuries, even if apparently superficial, may result in significant ocular damage. ERG may be useful in the diagnosis of visual loss attributed to disturbance in photoreceptor function, in the absence of anatomically evident damage.

Fig. 1

External photograph of the right eye showing the TASER dart firmly embedded in the lower lid

Fig. 2

Fundus photograph taken after the resolution of the exudative retinal detachment induced by the TASER. The resolving subretinal hemorrhage, as well as the adjacent smaller retinal hemorrhages, and pigmented scars are seen (asterisk). The montage shows the size and location of the detachment in relation to the posterior pole

Fig. 3

(Left) Axial view of the orbital CT scan showing the tip of the TASER dart in the right lacrimal fossa. (Right) Coronal section of the orbital CT scan. No evidence of globe or muscular lesion. The hemorrhagic fluid in left ethmoidal cells is the result of a broken nose, from a fall sustained after being “TASERed”

Fig. 4

Three-dimensional reconstructed CT image showing the location of the dart in the anterior orbit

Fig. 5

Ganzfeld electroretinogram performed 3 days after the TASER injury. a Isolated rod responses of the affected eye (OD; gray dashed line) compared to the concomitant response from the normal eye (OS; dark solid line). There is a 70% reduction in the b-wave amplitude of the affected relative to the fellow eye. b The ERG maximum response shows about a 63% reduction in the rod photoreceptor response, consistent with the b-wave reduction in a, and suggesting that the b-wave reduction results from reduced photoreceptor responses. The reduction in ERG amplitude in a and b is greater than what would be expected from the extent and location of the observed exudative retinal detachment. c Isolated cone responses to a single flash of light. Responses are vertically displaced for comparison. The response from the affected eye is reduced 10% when compared to the normal eye and is minimally delayed by 1–2 ms. d Isolated cone responses to a 30-Hz flickering light reflect the minimal amplitude and timing changes observed in c