Introduction

A variety of retinal and choroidal problems can result from trauma to the globe, such as subretinal haemorrhage, choroidal haemorrhage, retinal necrosis and atrophy, retinal tear or detachment, retinal dialysis, macular hole, traumatic maculopathy, commotio retinae, choroidal rupture, and chorioretinal rupture. The latter is also referred to as chorioretinitis sclopetaria (sclopetaria), which is traditionally associated with a high velocity missile that penetrates the orbit and passes adjacent to (or grazes), but does not penetrate, the globe.1

Originally manufactured and used by farmers and ranchers for marking trees and livestock, paintball has gained tremendous popularity among players of combat simulated games (‘war games’), leading to an increasing number of ocular injuries. Reports of eye injuries owing to paintballs began appearing in the medical literature as early as 1985.2 Since 1985, at least 200 cases have appeared in the English literature.3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24

In this report, we describe our experience with ocular paintball injuries and highlight the occurrence of sclopetaria secondary to this type of missile, even though it does not penetrate the orbit.

Materials and methods

We retrospectively reviewed cases of eye injury presenting to the Cole Eye Institute from 2000 to 2005. Those cases in which the injury was attributed to paintball sports were identified and evaluated to determine ocular findings and visual prognosis. The protocol was approved by the institutional review board at the Cleveland Clinic (IRB 8571).

To obtain previous reports of ocular paintball injuries, a PUBMED search was conducted using the following combination of search terms: paintball, paintball sports, and sports injuries. Additional studies were identified from bibliographies of the retrieved articles.

Results

Ocular paintball injuries occurred in eight male subjects and one female subject (nine eyes) with an average age of 16 years (range, 11–26). None had ocular protection at the time of ocular injury. On initial examination, vitreous haemorrhage was present in six eyes (67%), maculopathy, hyphema, cataract, and commotio retinae were each present in four eyes (44%) (Tables 1 and 2). Two eyes suffered retinal detachment and one eye an optic nerve avulsion. Sclopetaria occurred in four eyes (44%) (Figure 1).

Table 1 Details and ophthalmic findings of patients with paintball injuries in our series
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Table 2 Type and frequency of ocular findings secondary to ocular paintball injuries
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Figure 1
figure 1

Fundus photos. (a) Case 1; (b) Case 3. Both cases reveal the entity of chorioretinitis sclopetaria, as well traumatic maculopathy.

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Initial surgical management consisted of pars plana vitrectomy in five eyes (56%), lens removal in four eyes (44%), scleral buckle in two eyes (22%), repair of an open globe injury in one eye (11%), and enucleation in one eye (11%). One patient had no surgery (11%). Among the cases with sclopetaria, one patient underwent vitreoretinal surgery (case 1). In this case, a dense vitreous haemorrhage prevented adequate view of posterior segment and ultrasound revealed an area suspicious for a possible retinal tear and detachment, pars plana vitrectomy was performed, which revealed sclopetaria.

Follow-up time averaged 5 months (range, 1–13 months). On the final examination, the visual acuity was ⩾20/40 in three eyes, 20/50–20/150 in two eyes, and ⩽20/200 in four eyes. Seven eyes (78%) had improvement in visual acuity compared with the initial examination, one eye (11%) had the same visual acuity, and for one eye (11%) the initial visual acuity was unknown. The reason for diminished visual acuity in patients with visual acuity of ⩽20/50 was traumatic maculopathy in four eyes (44%), optic neuropathy in two eyes (22%), optic nerve avulsion in one eye (11%), and epiretinal membrane in one eye (11%).

Details of ocular injury could be obtained from 171 previous eyes reported in the literature (Table 2). Similar to our series, hyphema and vitreous haemorrhage represented the most prevalent major findings, 80 and 35%, respectively. Choroidal rupture was reported in 21 eyes (12%).

Discussion

Paintballs are small gelatin-shelled projectiles that are 17 mm in diameter, filled with non-toxic, water-soluble paint, and intended to explode on contact with an object with speeds up to 300 ft/s (91.5 m/s, 200 miles/h).3, 4 With 9.64 million paintball participants in the United States alone, paintball is the third most popular ‘extreme’ sport, behind inline skating and skateboarding.25 From 1997 to 2001, an estimated 11 998 people aged 7 years and older with paintball game related injuries were treated in hospital emergency departments for an average annual rate of 4.5 per 10 000 participants. Overall, the most common body part affected was the eye (42.7%).26

The best available data suggest that ocular injuries caused by paintballs leave at least 30% of individuals with ⩽20/200 best-corrected visual acuity.3 When ocular injuries were specified in the literature, vitreous haemorrhage and hyphema have been the most common findings as in our series (Table 2). However, we also noted a high frequency (44%) of sclopetaria in our series. Reports in the literature suggest that choroidal rupture occurs in 12% of patients, and retinal tear in 27% (Table 2). It may well be that the term sclopetaria was not appreciated in these cases because of confusion inherent in the term and/or considering the setting of this finding as it is usually reserved for cases of high speed projectiles penetrating orbit, but not globe.

Goldzieher, in 1901, introduced the term chorioretinitis plastica sclopetaria to describe the appearance of direct choroidal and retinal rupture in the peripheral retina following trauma from a bullet wound in the orbital area.27 The abbreviated term, chorioretinitis sclopetaria, is now more commonly used, however, the terms chorioretinitis proliferans, traumatic proliferating chorioretinitis, retinitis sclopetaria, retinitis sclopetarium, and acute retinal necrosis have all been used to describe this entity. Two theories exist for the derivation of the term chorioretinitis sclopetaria.1 Keeney proposed that the verb ‘sclow’ is an old English variant of ‘sclaw’ or ‘claw’ and sclopetaria characterizes the condition of scratching or clawing against the eye. Schoch believed that ‘sclopetum’ is a type of ‘culverin’, a 14th century Italian handgun.1

Fundus examination of sclopetaria demonstrates a fibroglial scar with sharp, serrated borders and pigment proliferation. The clinicopathologic features of sclopetaria include direct traumatic chorioretinal rupture followed by marked fibrovascular proliferation without retinal detachment.28 A simultaneous retraction of the choroid and retina at the site of the break reveals bare sclera with proliferation of fibrous tissue. Despite the presence of full thickness retinal tear, retinal detachment is rare even without surgical intervention because firm chorioretinal adhesion develops at the edges of the lesion. Martin et al29 describe successful management of seven of eight eyes with sclopetaria by initial observation only. The fact that a high percentage of patients with paintball injury present with a poor view of the fundus and also sclopetaria suggests that careful observation with sequential B-scans may help distinguish retinal tear and detachment from sclopetaria.

Sclopetaria is a rare manifestation of ocular trauma with the largest published series of only eight cases.29 To date, only a limited number of cases have been reported following a variety of injuries (Table 3).28, 29, 30, 31, 32, 33, 34, 35 Paintball injuries can cause anterior and posterior segment manifestations because of the unique form of injury the exploding gelatin pellets induce. It is important to recognize that ‘soft’ projectiles such as these can frequently induce sclopetaria even though they do not penetrate the orbit. Increased awareness and the need for proper ocular protection should also be emphasized by ophthalmologists.36

Table 3 Injuries associated with chorioretinitis sclopetaria
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