14.5 Penetrating Injury

Fig. 14.54 This patient suffered blunt trauma with a haemorrhagic globe. The eye is being explored. A scleral rupture was discovered at 12 oÕclock where the lens has been extruded from the eye and was found encapsulated underneath the superior rectus

Fig. 14.55 This composite photograph shows the effects of incarceration site superonasally which is dragging the retina into the incarceration causing tractional retinal detachment, despite silicone oil insertion

rhegmatogenous retinal detachment. However, not all incarcerations will progress, and some can be observed to watch for progression. Silicone oil insertion is recommended if intervention has been performed because of the risk of ongoing PVR formation. Unfortunately, these eyes are prone to late PVR even with silicone oil in or weeks after silicone oil removal.

Surgical Pearl of Wisdom

Before turning on the infusion cannula, it is important to look and verify proper positioning in the vitreous cavity. In complex cases where the view in to the eye is poor, it may be difÞcult to see the tip of the infusion cannula. Purposefully allow a few air bubbles in the infusion ßuid so when it is turned on you can see the bubbles behind the IOL or lens. This conÞrms the infusion cannula is in vitreous cavity.

Nancy M. Holekamp, Barnes Retina Institute, St. Louis,

Missouri, USA

14.4.3 Visual Outcome

14.5Penetrating Injury

14.5.1 Clinical Presentation

Sharp instruments may penetrate the sclera commonly in assault with glass bottles or knives but also other situations such as working with a screwdriver or other tool usually being used to loosen objects and being drawn back into the eye or even eating utensils (Feist et al. 1991). Projectiles such as pellets from air guns cause severe injury with the pellets often stopping at the orbital apex where additional damage is suffered by the optic nerve (Pulido et al. 1997; Enger et al. 1996; Schein et al. 1994). The tissues damaged

Studies have reported 40 % with no light perception (Morris et al. 1987a; Soheilian et al. 1996; Liggett et al. 1990b). In addition, there may be a cosmetic morbidity with a high risk of phthisis bulbi, occurring in two-thirds of the patients (Liggett et al. 1990b).

Fig. 14.56 This child was struck by a toy sword during play causing a penetrating injury and a haemorrhagic retinal detachment

depend on the site of entry, depth of penetration and the size of the object. As a result, any intraocular structure may be disrupted. Incarceration sites are problematic when the site of entry involves the sclera rather than cornea, resulting in later retinal detachment and phthisis. The injury can cause giant retinal tears (Aylward et al. 1993) or introduce material into the eye such as cilia (Gupta et al. 1996; Fortuin and Blanksma 1986) or ßy larvae (Gozum et al. 2003).

14.5.1.1 Endophthalmitis

Endophthalmitis may complicate any penetrating injury encountered in approximately 7 % (Essex et al. 2004a), with approximately 20 % having virulent organisms (Lieb et al. 2003). Species of Streptococcus, Staphylococcus and Bacillus are common in adults, with Streptococcus commonest in children (Miller et al. 2008; Alfaro et al. 1994b; Alfaro et al. 1995). Bacillus cereus is highly virulent and only a very rare cause of endophthalmitis without trauma (Reynolds and Flynn 1997; Foster et al. 1996). In trauma, unusual organisms can be detected (Essex et al. 2004b). Prophylactic intravitreal antibiotics have been reported to reduce endophthalmitis rates from 18 to 6 % in a study from India (Narang et al. 2003).

14.5.1.2 Retinal Detachment

Many types of retinal break are found in these traumatised eyes; they may develop at the time of impact or penetration or subsequently from incarceration of the retina.

Fig. 14.59 An ultrasound of an eye with choroidal haemorrhage from trauma

Penetrating trauma can tear the retina at the site of injury or may produce an incarceration of vitreous, retina and choroid. The latter progressively scars, shortening the vitreous and retina, which can produce tears often in the incarceration site.

Note: In penetrating injury, perform primary closure and watch for traction.