Art & science | polytrauma
Ocular injuries in people with multiple trauma Claire Kane and colleagues explain how emergency care practitioners should recognise, assess and treat patients with traumatic injury to the eye Correspondence [email protected] Claire Kane is a senior lecturer in adult nursing Dean Whiting is a senior lecturer in adult nursing Anthony McGrath is principal lecturer in advanced practice David Mathew is a senior learning technologist All at the University of Bedfordshire, Aylesbury Sarah Cocker is a practice development nurse in emergency nursing at Buckinghamshire Healthcare NHS Trust Esa Rintakorpi is a visiting lecturer in emergency trauma care and clinical nurse lead at Buckinghamshire Healthcare NHS Trust and the University of Bedfordshire Date submitted December 4 2013 Date accepted May 14 2014 Peer review This article has been subject to double-blind review and has been checked using antiplagiarism software Author guidelines en.rcnpublishing.com
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Abstract About 8% of all major trauma patients have eye injuries, which can have serious implications for the patients and their families. This article outlines a practical approach to the recognition, assessment and management in emergency departments of common ocular traumatic injuries. It also provides an overview of the applied anatomy, and discusses common complications. Keywords Eye injury, emergency care, polytrauma EYE INJURIES have a significant effect on the socioeconomic welfare of individuals, their families and the local economy (Cillino et al 2008). In emerging countries the incidence of visual morbidity is high in urban and rural areas, probably because adults and children work without visual protective equipment, and health and safety education (Vats et al 2008, Balaghafari et al 2013). In countries where safety legislation has been introduced, the outcomes of workplace ocular injuries are likely to have better prognoses (Kuhn et al 2006), although in the US there is said to be a high incidence of eye injuries in migrant workers (Quandt et al 2013). In urban communities incidents of ocular trauma are most likely to be sustained during major trauma, road traffic collisions, sports injuries and assaults (Kuhn et al 2006, Cillino et al 2008). People aged between ten and 35 years are at highest risk of eye injuries, as they are of other traumatic injuries (Guly et al 2006, Kuhn 2006, Cillino et al 2008), while people aged over 60 have poorer recoveries and outcomes.
A study of eye injuries sustained by British troops in Afghanistan reports that the proportion of lefteye injuries, at 54.5%, was significantly higher than right-eye injuries, at 44.5% (Blanch et al 2011). The cause of this phenomenon is unclear. There are data about ocular trauma from wars in Afghanistan and Iraq (Cockerham et al 2011), and in Israel and Lebanon (Mansour et al 2012), in which eye trauma, often caused by penetrating injury from glass and shrapnel, is associated with major trauma. The number of eye injuries sustained by British soldiers in the conflict in Afghanistan has declined over recent years due to the use of polycarbonate eye protection (Blanch et al 2011).
Anatomy The eye, referred to anatomically as the globe, is a spherical organ that measures about 2.5cm in diameter that is embedded in fat and situated anteriorly in the orbit (Watson 2009). Formed by seven bones of the skull, the orbit is a conical cavity that protects and houses the globe. Anteriorly, the eyelids and orbital rim protect the globe; superiorly, the bony walls differentiate the roof of the orbit from the frontal lobe of the brain and frontal sinus cavities. The eyelids are moveable folds of skin that contain cartilage and provide an external defence against foreign objects. The medial and inferior aspects of the orbital floor are separated from, respectively, the ethmoid and maxillary sinuses. Composed of thin bone, the aspects are common sites for ‘blow-out’ fractures, which can result in loss of visual acuity and visual field defects (Tortora and Derrickson 2011). A layer of adipose tissue surrounding the orbit provides further protection of the globe, and contains lymphatic vessels and veins that supply June 2014 | Volume 22 | Number 3 27
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Art & science | polytrauma the eye. Lubrication comes from lacrimal fluid and the sebaceous glands, which secrete a lubricating, antibacterial sebum directly onto the anterior portion of the globe to help maintain a moist environment and stop the eye drying out. The anatomical structures of the eye, including the lacrimal apparatus, extraocular muscles, eyelids, eyelashes, eyebrow and the conjunctiva, are known collectively as the ocular adnexa. The globe is attached to the orbit by four rectus muscles and two oblique muscles that collectively allow rotary movement and vision in many directions. The superior oblique muscle is innervated by the trochlear nerve, or cranial nerve IV; the lateral rectus muscle is innervated by the abducens nerve, or cranial nerve VI; and the other two muscles of the orbit are innervated by the oculomotor nerve, or cranial nerve III. Clinicians can remember this arrangement by recalling the mnemonic ‘SO4LR6, all the rest 3’. Damage or injury to one or more of these muscles causes the eye to deviate, producing what is commonly known as a squint (Watson 2009). The globe and its contents are themselves contained in three anatomical layers. These include a fibrous collagen layer called the sclera, which is overlaid by the conjunctiva and, along with the cornea, helps protect the outermost aspect of the eyeball. The middle layer is highly vascular and contains the ciliary body, the choroid and the iris (Watson 2009), while the innermost third layer, the retina, lines the posterior aspect of the globe and contains the nerve cells required for the reception of light rays. Light reflected from the retina is often seen in photographs as ‘red eye’.
Posterior to the pupil and iris is the lens, which is connected to the sclera by connective fibres. The lens divides the globe into the posterior segment, which contains viscous vitreous humor, and the anterior segment, which contains aqueous humor. The iris subdivides the anterior segment into the anterior and posterior chambers (Tortora and Derrickson 2011). The optic nerve sheath, which is an extension of the dura mater, contains the ophthalmic artery, the optic nerve and small veins. The sensory optic nerve, which conducts visual signals from the retina to the brain, passes through the optic foramen and crosses over at the optic chiasm (Watson 2009). At the optic chiasm, the medial axons of the nerve cross over to the opposite side of the brain, while the lateral axons continue on the same trajectory. Both extend to the primary visual area of the brain, where the signals from the retina are processed into visual detail. Disorders and damage to the nerve result in visual disturbances, and in some cases loss of vision. The anatomical structure and an anterior view of the eye are shown in Figure 1.
Assessment Detailed examinations of eye injuries should be undertaken by senior emergency department (ED) doctors or nurses who are competent in assessing ocular trauma. Ophthalmic assessment is part of the secondary survey in trauma care, when patients should be physiologically stable. As with isolated eye trauma, careful histories of the mechanisms of injury are vital and attention must be paid to reports of visual disturbance.
Figure 1 Anatomical structure and anterior view of the eye Anterior view
Ciliary body Superior rectus muscle Posterior segment
Ciliary zonular fibres
Lateral
Lens
Retinal vessels
Anterior chamber
Macula with fovea centralis
Cornea Iris
Optic nerve Optic disc Inferior oblique muscle Peter Lamb
Medial
Inferior rectus muscle
28 June 2014 | Volume 22 | Number 3
Posterior chamber Canal of Schlemm Sclera
Caruncula lacrimalis
Bulbar conjunctiva
Pupil
Iris
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In patients who have sustained eye injuries and are unconscious, initial clinical examinations should be undertaken as part of secondary surveys and ophthalmic referrals should be made for specialist opinions. Ideally, examinations should be made using a slit lamp, although this is not always practicable. If patients have swollen eyelids, these should be retracted carefully for examination. If more detailed examinations are needed, ophthalmologists can use surgical retractors (Greaves et al 2009). Ophthalmic assessments should be part of secondary surveys in polytrauma and findings must be clearly documented. The difficulties associated with assessing patients on trolleys rather than in more ideal settings should not deter clinicians from the task, and EDs should be equipped to deal with eye assessments at the patient’s bedside as an essential part of trauma care. Assessments of the eye involve tests of visual acuity, pupillary reflex, eye movement and visual field. Visual acuity Assessment begins with inspection of the patient’s face and eye area. Before palpation around the orbital rim and the eye, the globe must be inspected fully. The most important assessment is of visual acuity, which ideally involves asking patients to stand six metres away from a full-sized Snellen chart and identify its characters (Skinner and Driscoll 2013). However, patients are usually injured and laid flat on trolleys, so alternative methods should be adopted. Patients can be asked to identify characters on half-sized Snellen charts placed on the ceiling of the trauma bay, for example, or on even smaller Snellen charts, known as near charts, that are held by practitioners. If such charts are unavailable, patients can be asked to read a standard hospital label or count the number of fingers that the clinician holds up (Skinner and Driscoll 2013). If they cannot see fingers, practitioners should check whether they can detect hand movements; if they cannot do this, practitioners should determine if they can distinguish between light and dark (Kanski 2004). If patients who need glasses do not have them or if they are broken, a pinhole can be used to diffract light and concentrate the patients’ vision on the chart. Pupillary reflex The next stage of assessment is a bright-light examination, in which the pupillary reflex function of the oculomotor nerve is tested (Fuller 2013). EMERGENCY NURSE
Practitioners should examine patients’ pupils for size and symmetry before pointing a light at one eye and then the other to check pupillary constriction in each pupil. Practitioners should then repeat the process but, when pointing the light at one eye, should check the other for consensual constriction. They should repeat the process again to check for a relative afferent pupillary defect, also known as the Marcus Gunn pupil sign, in which the pupil appears to dilate rather than constrict in comparison with the unaffected eye. This form of pupil dilation, or mydriasis, is a sign of injury or lesion between the retina and the optic chiasm, while a unilaterally dilated or irregular pupil is a sign of potentially serious injury to the oculomotor nerve or of penetrating trauma (Kanski 2004, Fuller 2013). During these examinations pain relief is important and a topical analgesia, such as tetracaine, should be used before mydriatic eye drops, such as cyclopentolate, are administered. These eye drops help examinations because they relax the pupils but, because they also dilate the pupils, they should be administered after papillary reflex has been tested. Mydriatics increase intraocular pressure, however, and so should not be used if there is globe rupture (Kim 2000, Constable and Pirmohamed 2004, British National Formulary 2013). Eye movement The next stage of examinations is a thorough fundoscopy, in which eye movements are checked by testing cranial nerves. If mechanical movement of the eye is limited, the inferior rectus muscle may be trapped due to orbital floor, or blow out, fracture. Neurogenic reasons for eye movement defects include a third-nerve palsy causing dropping or falling eyelids, or ptosis, and double vision, or diplopia; and a fourth- and sixth-nerve palsy causing diplopia (Fuller 2013). Involuntary lateral eye movements, or nystagmus, may also be present. Visual field The final stage of examinations involves assessment of visual field pattern. Visual field defects can be unilateral or bilateral, and can manifest in patients’ peripheral or central field of vision (Kanski 2004, Skinner and Driscoll 2013). Central-field blind spots, or scotomas, are often due to optic nerve damage and cause a loss of visual acuity. Scotomas are usually asymmetrical and unilateral, and can occur due to macular holes in open or closed globe trauma (Weichel and Colyer 2009). If patients have decreased vision, or hemianopia, or gaps in vision, they should be referred to an ophthalmologist for assessment. June 2014 | Volume 22 | Number 3 29
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Art & science | polytrauma Generic approach to management In patients with polytrauma, the immediate management of life-threatening conditions, such as airway compromise or haemorrhagic shock, should take precedence. Nevertheless, it is vital that attention is given to injured eyes early and, although some specific injuries require specialist interventions, the following generic management strategies should be applied with all presentations. Once initial stabilisation has been established, an urgent referral should be made to an ophthalmologist along with information (Lindfield and Das-Bhaumik 2009) about: ■■ The time and mechanism of injury, including the types, velocities and proximities of objects involved, and whether there is a potential for infection. ■■ Pupillary reactions. ■■ Visual acuity. ■■ Examination findings. ■■ Lacerations to the eyelid margin. ■■ Treatments administered so far. Such referrals are important because surgical interventions must be co-ordinated to avoid delays. Patients’ affected eyes should be protected by shields, fixed in place with surgical tape, although improvised shields can be made from cut-down polystyrene cups or gallipots. Eye pads should not be placed on injured eyes because they can increase intraocular pressure and cause herniation of ocular contents (Bord and Linden 2008, Lindfield and Das‑Bhaumik 2009). Patients should remain nil by mouth because immediate surgery may be required for eye or concomitant injuries. Systemic analgesia should be considered early for pain management, and antiemetics may be required to prevent nausea and vomiting, which can increase intraocular pressure. Broad spectrum antibiotics should also be considered at this stage (Woodcock 2009).
Alamy
Figure 2 Result of an injury to the cornea caused by a small piece of a metal saw blade
30 June 2014 | Volume 22 | Number 3
Removal of embedded foreign bodies from eyes by anyone other than an ophthalmologist is contraindicated. Instead, patients should be nursed either supine or, unless contraindicated by other injuries, at a 30° angle to reduce intraocular pressure and the risk of further ocular injuries (Marsden 2013). However, patients with blood in the anterior chamber of the eye, or traumatic hyphema, should, if possible, sit upright to aid postural drainage of blood from the visual axis to reduce intraocular pressure, and the risks of corneal staining and vision defects (Marsden 2013). In the context of major trauma, cervical spine injuries should be assessed before patients’ positions are changed. Eye injuries, like all traumatic injuries, often have medicolegal consequences, so it is imperative that healthcare professionals observe good practice and document it accurately. Clinical photography is widely encouraged but should not delay treatment.
Injury patterns in polytrauma Corneal injury According to Trauma Audit and Research Network (TARN) data, a retrospective analysis of trauma patient treatments in the UK between 1989 and 2004, the most common traumatic eye injury is to the cornea (Guly et al 2006). Corneal abrasions occur when foreign bodies enter or scratch the surface of the eye, and patients with such injuries can present with pain, irritation, photophobia or decreased visual acuity. Care should be taken when removing foreign bodies, such as glass from the around the eyes of a patient who has been in a road traffic collision, because parts of them may be embedded in the cornea, in which case the patients concerned should be referred to an ophthalmologist. One result of a corneal injury caused by a small piece of metal from a broken saw blade is shown in Figure 2. Fluorescein dye and cobalt-blue light are essential for diagnosing corneal and penetrating injuries. In the Seidel test for penetrating injuries, concentrated fluorescein dye is applied directly over a potential site of perforation while it is being observed under blue light from the slit lamp. If a perforation and leak are present, the fluorescein dye will appear as a green stream in the dark orange dye (Kim 2000). Optic nerve injury Of all cranial nerves associated with the eye, the optic nerve is most likely to sustain injury and such injuries often lead to reduced visual acuity. Optic nerve damage is associated with penetrating injuries, indirect contusion, EMERGENCY NURSE
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Eyelid injuries Evidence suggests that the widespread use of seatbelts in vehicles has reduced the incidence of most injuries sustained in road traffic collisions (World Health Organization 2013). However, the use of airbags in vehicles may have led to an increase in incidence of eye injuries, of which the most common is injury to the eyelid (McGwin and Owsley 2005). Eyelid injuries can involve substantial bruising and swelling, which can mask injuries underneath. However, lacerations to the upper and lower lid are often superficial, and can be sutured following examination of the globe. Patients whose eyelids have sustained deep horizontal lacerations, which can result in ptosis if inadequately repaired, should be referred to an ophthalmologist. Wounds to the lid margin often cause entropion, in which the eyelid folds inwards, or ectropion, in which the eyelid folds outwards. In either case the eyelid becomes difficult to close and the patients concerned require ophthalmology referral (American College of Surgeons Committee on Trauma (ACSCT) 2008). Obstruction If there are wounds in the medial canaliculus, lacrimal sac or nasal lacrimal sac, obstruction can occur and the injuries must be reviewed by an ophthalmologist. Globe rupture Airbags are also implicated in one of the more serious eye injuries, namely globe rupture (Salam et al 2010). Suspicion of globe rupture should be high if the patients concerned have sustained blunt trauma to the face or eyes and if there is marked visual disturbance (Bord and Linden 2008, Lindfield and Das-Bhaumik 2009). In an anterior rupture, the integrity of the globe may be disrupted and ocular contents may be leaking from the eye, which becomes soft due to the reduced intraocular pressure. If the globe has sustained a penetrating injury caused by a fine, sharp fragment, disruption may be less obvious, but subtle signs of anterior rupture, such as a shallow anterior chamber, distorted iris or a focal EMERGENCY NURSE
Figure 3 The skull with, inset, fracture to the orbit
Fracture to orbit Alamy
facial fractures and by compression caused by orbital compartment syndrome, or swelling in the orbit (Guly et al 2006). In major trauma patients, orbital nerve damage can occur acutely as a result of haemorrhage, or as a result of infection or orbital emphysema (Skinner and Driscoll 2013), so clinicians must be alert to an increase in pain, altered pupil reactions and decreased vision. Urgent treatment is required to drain the pressure in the orbit and reverse the crisis.
cataract, may be discernible. If post-traumatic endophthalmitis, or inflammation of the internal layer of the eye, is present, it should be treated as a medical emergency with systemic and intravitreal antibiotics (Durand 2013). The main goal of treatment in the trauma environment is to prevent further damage. If globe rupture is suspected, the eye should not be physically examined any further, a protective shield should be applied and the patient should be referred to an ophthalmologist urgently (Bord and Linden 2008, Lindfield and Das-Bhaumik 2009). Orbital injuries Blunt trauma to the orbital region can result in fracture of the bony orbit, the weakest point of which is the orbital floor. Such blow out fractures can cause the orbital contents to herniate into the antrum. They should be suspected if there is swelling and bruising of the eyelids and periorbital tissues, and if the patients concerned are in pain. Enophthalmos, or the sinking or displacement of the eyeball in the orbit, and exophthalmos, also known as exophthalmia, or bulging of the eye, can also occur as a consequence of a posterior bleed or fracture. Patients with damage to the maxillary nerve can present with diplopia, reduced ocular movement, facial asymmetry and reduced cheek sensation (ACSCT 2008, Skinner and Driscoll 2013). A fracture of the orbit is shown in Figure 3. June 2014 | Volume 22 | Number 3 31
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Art & science | polytrauma Subcutaneous emphysema or subconjunctival haemorrhage can occur if there is a fracture to the ethmoid or maxillary sinus. In such cases, surgery should usually take place only after the swelling has reduced but can be expedited if a blow out fracture has triggered a significant oculocardiac reflex leading to severe bradycardia (Skinner and Driscoll 2013). The Valsalva manoeuvre, in which the patient blocks the nostrils and attempts to exhale through the nose, is contraindicated in those with orbital fracture because it can force air from the sinuses into the surrounding tissues, potentially causing further swelling and globe-content disruption (Greaves et al 2009). Such patients should be advised not to blow their noses or strain during defecation. Burns If the eye has been contaminated by chemicals, urgent action is required to prevent further damage and loss of sight. Topical anaesthetic should be administered before starting vigorous and copious irrigation to remove and neutralise contaminants. Normal saline is an appropriate, readily available solution to use for most chemicals and, if the chemical is unknown, the National Poisons Information Service can be contacted for advice. During irrigation, the eyelid may contract and twitch, and may require manual manipulation. Lenses that deliver a continuous flow of solution to injured eyes can help in these situations but may be contraindicated by the presence of other injuries.
In thermal injuries, the eyelid is injured usually as a result of defensive eye closure, and corneal injury is rare. Burns to the globe, which are also infrequent, require application of a sterile dressing to occlude the eye and referral of the patient to an ophthalmologist (ACSCT 2008).
Conclusion Patients with polytrauma are vulnerable to reduced visual acuity and early detection of eye injuries is vital to improve their long-term outcomes (Georgouli et al 2011). The TARN study states that all patients with major trauma should be checked for eye injuries because, although the prevalence of ocular trauma is low, it increases by up to 7% in patients with facial fractures, especially young adults (Guly et al 2006). If eye injuries are overlooked in major trauma care, treatment can be delayed and the chances of good outcomes reduced, which can have a devastating effect on patients and their families. Nurses should therefore be able to recognise the presence of, or potential for, acute eye injuries in patients with polytrauma, and should have the skills required to provide immediate symptom relief and make the appropriate referrals as necessary.
Find out more The National Poisons Information Service can be contacted at www.npis.org
Online archive For related information, visit our online archive and search using the keywords Conflict of interest None declared
References American College of Surgeons Committee on Trauma (2008) Advanced Trauma Life Support for Doctors. Eighth edition. ACS, Chicago IL.
Constable S, Pirmohamed M (2004) Drugs and the retina. Expert Opinion in Drug Safety. 3, 3, 249.
Balaghafari A, Siamian H, Aligolbandi K (2013) Ocular Trauma: 2 years retrospective study in Sari, Iran. Materia Socio Medica. 25, 4, 230-232.
Durand M (2013) Endophthalmitis. Clinical Microbiology and Infection. 19, 3, 227-234.
Blanch R, Bindra M, Jacks A et al (2011) Ophthalmic injuries in British Armed Forces in Iraq and Afghanistan. Eye Journal. 25, 2, 218–223. Bord S, Linden J (2008) Trauma to the globe and orbit. Emergency Medicine Clinics of North America. 26, 1, 97-123. British National Formulary (2013) British National Formulary No 66. British Medical Association and the Royal Pharmaceutical Society of Great Britain, London. Cillino S, Cascuccio A, Di Pace F et al (2008) A five-year retrospective study of epidemiological characteristics and visual outcomes of patients hospitalised for ocular trauma in a Mediterranean area. BMC Ophthalmology. doi:10.1186/1471-2415-8-6 Cockerham G, Rice T, Hewes E et al (2011) Closed-eye ocular injuries in the Iraq and Afghanistan wars. New England Journal of Medicine. doi: 10.1056/NEJMc1010683.
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Fuller G (2013) Neurological Examination Made Easy. Fifth edition. Churchill-Livingstone, Edinburgh. Georgouli T, Pountos I, Chang B et al (2011) Prevalence of ocular and orbital injuries in polytrauma patients. European Journal of Trauma and Emergency Surgery. 37, 2, 135-140. Greaves I, Porter K, Garner J (2009) Trauma Care Manual. Hodder Arnold, London. Guly C, Guly H, Bouamra O et al (2006) Ocular injuries in patients with major trauma. Emergency Medicine Journal. 23, 12, 915-917. Kanski J (2004) Clinical Ophthalmology: A Synopsis. Butterworth-Heinemann, Edinburgh. Kim J (2000) The use of vital dyes in corneal disease. Current Opinion in Ophthalmology. 11, 4, 241-247. Kuhn F, Morris R, Witherspoon C (2006) Epidemiology of blinding trauma in the United States eye injury registry. Ophthalmic Epidemiology. 13, 3, 209-216.
Lindfield D, Das-Bhaumik R (2009) Emergency department management of penetrating eye injuries. International Emergency Nurse. 17, 3, 155-160. Mansour A, Hamade H, Ghaddar A et al (2012) Cluster bomb ocular injuries. Middle East African Journal of Ophthalomology. 19, 1, 153-157. Marsden J (2013) Opthhalmic emergencies. In Dolan B, Holt L (Eds) Accident and Emergency: Theory into Practice. Baillière Tindall, Edinburgh. McGwin G, Owsley C (2005) Risk factors for motor vehicle collision related eye injuries. Archives of Ophthalmology. 123, 1, 89-95. Quandt S, Schulz M, Talton J et al (2013) Occupational eye injuries experienced by migrant farmworkers. Journal of Agromedicine. 17, 1, 63-69. doi: 10.1080/1059924X.2012.629918 Salam T, Stravraskas P, Wickham L et al (2010) Case report: airbag injury and bilateral globe rupture. American Journal of Emergency Medicine. 28, 982, 5-6. Scruggs D, Scruggs R, Stukenborg G et al (2012) Ocular injuries in trauma patients: an analysis of 28,340 trauma admissions in
the 2003-2007 National Trauma Data Bank national sample programme. Journal of Trauma and Acute Care Surgery. 73, 5, 1308-1312. Skinner D, Driscoll P (2013) ABC of Major Trauma. Fourth edition. Wiley-Blackwell, Oxford. Tortora G, Derrickson B (2011) Principles of Anatomy and Physiology. 13th edition. Wiley-Blackwell, Oxford. Vats S, Murthy G, Chandra M et al (2008) Epidimiological study of ocular trauma in an urban slum population in Delhi, India. Indian Journal of Ophthalmology. 56, 4, 313-316. Watson R (2009) Anatomy and Physiology for Nurses. 12th edition. Elsevier, Edinburgh. Weichel E, Colyer M (2009) Traumatic macular holes secondary to combat ocular trauma. Retina. 29, 3, 349-354. Woodcock M (2009) Ophthalmic injuries. In Greaves I, Porter K, Garner J (Eds) Trauma Care Manual. Hodder Arnold, London. World Health Organization (2013) Violence and Injury Prevention: Global Status Report on Road Safety. tinyurl.com/olar7fq (Last accessed: May 19 2014.)
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Ocular injuries in people with multiple trauma Claire Kane and colleagues explain how emergency care practitioners should recognise, assess and treat patients with traumatic injury to the eye Correspondence [email protected] Claire Kane is a senior lecturer in adult nursing Dean Whiting is a senior lecturer in adult nursing Anthony McGrath is principal lecturer in advanced practice David Mathew is a senior learning technologist All at the University of Bedfordshire, Aylesbury Sarah Cocker is a practice development nurse in emergency nursing at Buckinghamshire Healthcare NHS Trust Esa Rintakorpi is a visiting lecturer in emergency trauma care and clinical nurse lead at Buckinghamshire Healthcare NHS Trust and the University of Bedfordshire Date submitted December 4 2013 Date accepted May 14 2014 Peer review This article has been subject to double-blind review and has been checked using antiplagiarism software Author guidelines en.rcnpublishing.com
EMERGENCY NURSE
Abstract About 8% of all major trauma patients have eye injuries, which can have serious implications for the patients and their families. This article outlines a practical approach to the recognition, assessment and management in emergency departments of common ocular traumatic injuries. It also provides an overview of the applied anatomy, and discusses common complications. Keywords Eye injury, emergency care, polytrauma EYE INJURIES have a significant effect on the socioeconomic welfare of individuals, their families and the local economy (Cillino et al 2008). In emerging countries the incidence of visual morbidity is high in urban and rural areas, probably because adults and children work without visual protective equipment, and health and safety education (Vats et al 2008, Balaghafari et al 2013). In countries where safety legislation has been introduced, the outcomes of workplace ocular injuries are likely to have better prognoses (Kuhn et al 2006), although in the US there is said to be a high incidence of eye injuries in migrant workers (Quandt et al 2013). In urban communities incidents of ocular trauma are most likely to be sustained during major trauma, road traffic collisions, sports injuries and assaults (Kuhn et al 2006, Cillino et al 2008). People aged between ten and 35 years are at highest risk of eye injuries, as they are of other traumatic injuries (Guly et al 2006, Kuhn 2006, Cillino et al 2008), while people aged over 60 have poorer recoveries and outcomes.
A study of eye injuries sustained by British troops in Afghanistan reports that the proportion of lefteye injuries, at 54.5%, was significantly higher than right-eye injuries, at 44.5% (Blanch et al 2011). The cause of this phenomenon is unclear. There are data about ocular trauma from wars in Afghanistan and Iraq (Cockerham et al 2011), and in Israel and Lebanon (Mansour et al 2012), in which eye trauma, often caused by penetrating injury from glass and shrapnel, is associated with major trauma. The number of eye injuries sustained by British soldiers in the conflict in Afghanistan has declined over recent years due to the use of polycarbonate eye protection (Blanch et al 2011).
Anatomy The eye, referred to anatomically as the globe, is a spherical organ that measures about 2.5cm in diameter that is embedded in fat and situated anteriorly in the orbit (Watson 2009). Formed by seven bones of the skull, the orbit is a conical cavity that protects and houses the globe. Anteriorly, the eyelids and orbital rim protect the globe; superiorly, the bony walls differentiate the roof of the orbit from the frontal lobe of the brain and frontal sinus cavities. The eyelids are moveable folds of skin that contain cartilage and provide an external defence against foreign objects. The medial and inferior aspects of the orbital floor are separated from, respectively, the ethmoid and maxillary sinuses. Composed of thin bone, the aspects are common sites for ‘blow-out’ fractures, which can result in loss of visual acuity and visual field defects (Tortora and Derrickson 2011). A layer of adipose tissue surrounding the orbit provides further protection of the globe, and contains lymphatic vessels and veins that supply June 2014 | Volume 22 | Number 3 27
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Art & science | polytrauma the eye. Lubrication comes from lacrimal fluid and the sebaceous glands, which secrete a lubricating, antibacterial sebum directly onto the anterior portion of the globe to help maintain a moist environment and stop the eye drying out. The anatomical structures of the eye, including the lacrimal apparatus, extraocular muscles, eyelids, eyelashes, eyebrow and the conjunctiva, are known collectively as the ocular adnexa. The globe is attached to the orbit by four rectus muscles and two oblique muscles that collectively allow rotary movement and vision in many directions. The superior oblique muscle is innervated by the trochlear nerve, or cranial nerve IV; the lateral rectus muscle is innervated by the abducens nerve, or cranial nerve VI; and the other two muscles of the orbit are innervated by the oculomotor nerve, or cranial nerve III. Clinicians can remember this arrangement by recalling the mnemonic ‘SO4LR6, all the rest 3’. Damage or injury to one or more of these muscles causes the eye to deviate, producing what is commonly known as a squint (Watson 2009). The globe and its contents are themselves contained in three anatomical layers. These include a fibrous collagen layer called the sclera, which is overlaid by the conjunctiva and, along with the cornea, helps protect the outermost aspect of the eyeball. The middle layer is highly vascular and contains the ciliary body, the choroid and the iris (Watson 2009), while the innermost third layer, the retina, lines the posterior aspect of the globe and contains the nerve cells required for the reception of light rays. Light reflected from the retina is often seen in photographs as ‘red eye’.
Posterior to the pupil and iris is the lens, which is connected to the sclera by connective fibres. The lens divides the globe into the posterior segment, which contains viscous vitreous humor, and the anterior segment, which contains aqueous humor. The iris subdivides the anterior segment into the anterior and posterior chambers (Tortora and Derrickson 2011). The optic nerve sheath, which is an extension of the dura mater, contains the ophthalmic artery, the optic nerve and small veins. The sensory optic nerve, which conducts visual signals from the retina to the brain, passes through the optic foramen and crosses over at the optic chiasm (Watson 2009). At the optic chiasm, the medial axons of the nerve cross over to the opposite side of the brain, while the lateral axons continue on the same trajectory. Both extend to the primary visual area of the brain, where the signals from the retina are processed into visual detail. Disorders and damage to the nerve result in visual disturbances, and in some cases loss of vision. The anatomical structure and an anterior view of the eye are shown in Figure 1.
Assessment Detailed examinations of eye injuries should be undertaken by senior emergency department (ED) doctors or nurses who are competent in assessing ocular trauma. Ophthalmic assessment is part of the secondary survey in trauma care, when patients should be physiologically stable. As with isolated eye trauma, careful histories of the mechanisms of injury are vital and attention must be paid to reports of visual disturbance.
Figure 1 Anatomical structure and anterior view of the eye Anterior view
Ciliary body Superior rectus muscle Posterior segment
Ciliary zonular fibres
Lateral
Lens
Retinal vessels
Anterior chamber
Macula with fovea centralis
Cornea Iris
Optic nerve Optic disc Inferior oblique muscle Peter Lamb
Medial
Inferior rectus muscle
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Posterior chamber Canal of Schlemm Sclera
Caruncula lacrimalis
Bulbar conjunctiva
Pupil
Iris
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In patients who have sustained eye injuries and are unconscious, initial clinical examinations should be undertaken as part of secondary surveys and ophthalmic referrals should be made for specialist opinions. Ideally, examinations should be made using a slit lamp, although this is not always practicable. If patients have swollen eyelids, these should be retracted carefully for examination. If more detailed examinations are needed, ophthalmologists can use surgical retractors (Greaves et al 2009). Ophthalmic assessments should be part of secondary surveys in polytrauma and findings must be clearly documented. The difficulties associated with assessing patients on trolleys rather than in more ideal settings should not deter clinicians from the task, and EDs should be equipped to deal with eye assessments at the patient’s bedside as an essential part of trauma care. Assessments of the eye involve tests of visual acuity, pupillary reflex, eye movement and visual field. Visual acuity Assessment begins with inspection of the patient’s face and eye area. Before palpation around the orbital rim and the eye, the globe must be inspected fully. The most important assessment is of visual acuity, which ideally involves asking patients to stand six metres away from a full-sized Snellen chart and identify its characters (Skinner and Driscoll 2013). However, patients are usually injured and laid flat on trolleys, so alternative methods should be adopted. Patients can be asked to identify characters on half-sized Snellen charts placed on the ceiling of the trauma bay, for example, or on even smaller Snellen charts, known as near charts, that are held by practitioners. If such charts are unavailable, patients can be asked to read a standard hospital label or count the number of fingers that the clinician holds up (Skinner and Driscoll 2013). If they cannot see fingers, practitioners should check whether they can detect hand movements; if they cannot do this, practitioners should determine if they can distinguish between light and dark (Kanski 2004). If patients who need glasses do not have them or if they are broken, a pinhole can be used to diffract light and concentrate the patients’ vision on the chart. Pupillary reflex The next stage of assessment is a bright-light examination, in which the pupillary reflex function of the oculomotor nerve is tested (Fuller 2013). EMERGENCY NURSE
Practitioners should examine patients’ pupils for size and symmetry before pointing a light at one eye and then the other to check pupillary constriction in each pupil. Practitioners should then repeat the process but, when pointing the light at one eye, should check the other for consensual constriction. They should repeat the process again to check for a relative afferent pupillary defect, also known as the Marcus Gunn pupil sign, in which the pupil appears to dilate rather than constrict in comparison with the unaffected eye. This form of pupil dilation, or mydriasis, is a sign of injury or lesion between the retina and the optic chiasm, while a unilaterally dilated or irregular pupil is a sign of potentially serious injury to the oculomotor nerve or of penetrating trauma (Kanski 2004, Fuller 2013). During these examinations pain relief is important and a topical analgesia, such as tetracaine, should be used before mydriatic eye drops, such as cyclopentolate, are administered. These eye drops help examinations because they relax the pupils but, because they also dilate the pupils, they should be administered after papillary reflex has been tested. Mydriatics increase intraocular pressure, however, and so should not be used if there is globe rupture (Kim 2000, Constable and Pirmohamed 2004, British National Formulary 2013). Eye movement The next stage of examinations is a thorough fundoscopy, in which eye movements are checked by testing cranial nerves. If mechanical movement of the eye is limited, the inferior rectus muscle may be trapped due to orbital floor, or blow out, fracture. Neurogenic reasons for eye movement defects include a third-nerve palsy causing dropping or falling eyelids, or ptosis, and double vision, or diplopia; and a fourth- and sixth-nerve palsy causing diplopia (Fuller 2013). Involuntary lateral eye movements, or nystagmus, may also be present. Visual field The final stage of examinations involves assessment of visual field pattern. Visual field defects can be unilateral or bilateral, and can manifest in patients’ peripheral or central field of vision (Kanski 2004, Skinner and Driscoll 2013). Central-field blind spots, or scotomas, are often due to optic nerve damage and cause a loss of visual acuity. Scotomas are usually asymmetrical and unilateral, and can occur due to macular holes in open or closed globe trauma (Weichel and Colyer 2009). If patients have decreased vision, or hemianopia, or gaps in vision, they should be referred to an ophthalmologist for assessment. June 2014 | Volume 22 | Number 3 29
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Art & science | polytrauma Generic approach to management In patients with polytrauma, the immediate management of life-threatening conditions, such as airway compromise or haemorrhagic shock, should take precedence. Nevertheless, it is vital that attention is given to injured eyes early and, although some specific injuries require specialist interventions, the following generic management strategies should be applied with all presentations. Once initial stabilisation has been established, an urgent referral should be made to an ophthalmologist along with information (Lindfield and Das-Bhaumik 2009) about: ■■ The time and mechanism of injury, including the types, velocities and proximities of objects involved, and whether there is a potential for infection. ■■ Pupillary reactions. ■■ Visual acuity. ■■ Examination findings. ■■ Lacerations to the eyelid margin. ■■ Treatments administered so far. Such referrals are important because surgical interventions must be co-ordinated to avoid delays. Patients’ affected eyes should be protected by shields, fixed in place with surgical tape, although improvised shields can be made from cut-down polystyrene cups or gallipots. Eye pads should not be placed on injured eyes because they can increase intraocular pressure and cause herniation of ocular contents (Bord and Linden 2008, Lindfield and Das‑Bhaumik 2009). Patients should remain nil by mouth because immediate surgery may be required for eye or concomitant injuries. Systemic analgesia should be considered early for pain management, and antiemetics may be required to prevent nausea and vomiting, which can increase intraocular pressure. Broad spectrum antibiotics should also be considered at this stage (Woodcock 2009).
Alamy
Figure 2 Result of an injury to the cornea caused by a small piece of a metal saw blade
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Removal of embedded foreign bodies from eyes by anyone other than an ophthalmologist is contraindicated. Instead, patients should be nursed either supine or, unless contraindicated by other injuries, at a 30° angle to reduce intraocular pressure and the risk of further ocular injuries (Marsden 2013). However, patients with blood in the anterior chamber of the eye, or traumatic hyphema, should, if possible, sit upright to aid postural drainage of blood from the visual axis to reduce intraocular pressure, and the risks of corneal staining and vision defects (Marsden 2013). In the context of major trauma, cervical spine injuries should be assessed before patients’ positions are changed. Eye injuries, like all traumatic injuries, often have medicolegal consequences, so it is imperative that healthcare professionals observe good practice and document it accurately. Clinical photography is widely encouraged but should not delay treatment.
Injury patterns in polytrauma Corneal injury According to Trauma Audit and Research Network (TARN) data, a retrospective analysis of trauma patient treatments in the UK between 1989 and 2004, the most common traumatic eye injury is to the cornea (Guly et al 2006). Corneal abrasions occur when foreign bodies enter or scratch the surface of the eye, and patients with such injuries can present with pain, irritation, photophobia or decreased visual acuity. Care should be taken when removing foreign bodies, such as glass from the around the eyes of a patient who has been in a road traffic collision, because parts of them may be embedded in the cornea, in which case the patients concerned should be referred to an ophthalmologist. One result of a corneal injury caused by a small piece of metal from a broken saw blade is shown in Figure 2. Fluorescein dye and cobalt-blue light are essential for diagnosing corneal and penetrating injuries. In the Seidel test for penetrating injuries, concentrated fluorescein dye is applied directly over a potential site of perforation while it is being observed under blue light from the slit lamp. If a perforation and leak are present, the fluorescein dye will appear as a green stream in the dark orange dye (Kim 2000). Optic nerve injury Of all cranial nerves associated with the eye, the optic nerve is most likely to sustain injury and such injuries often lead to reduced visual acuity. Optic nerve damage is associated with penetrating injuries, indirect contusion, EMERGENCY NURSE
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Eyelid injuries Evidence suggests that the widespread use of seatbelts in vehicles has reduced the incidence of most injuries sustained in road traffic collisions (World Health Organization 2013). However, the use of airbags in vehicles may have led to an increase in incidence of eye injuries, of which the most common is injury to the eyelid (McGwin and Owsley 2005). Eyelid injuries can involve substantial bruising and swelling, which can mask injuries underneath. However, lacerations to the upper and lower lid are often superficial, and can be sutured following examination of the globe. Patients whose eyelids have sustained deep horizontal lacerations, which can result in ptosis if inadequately repaired, should be referred to an ophthalmologist. Wounds to the lid margin often cause entropion, in which the eyelid folds inwards, or ectropion, in which the eyelid folds outwards. In either case the eyelid becomes difficult to close and the patients concerned require ophthalmology referral (American College of Surgeons Committee on Trauma (ACSCT) 2008). Obstruction If there are wounds in the medial canaliculus, lacrimal sac or nasal lacrimal sac, obstruction can occur and the injuries must be reviewed by an ophthalmologist. Globe rupture Airbags are also implicated in one of the more serious eye injuries, namely globe rupture (Salam et al 2010). Suspicion of globe rupture should be high if the patients concerned have sustained blunt trauma to the face or eyes and if there is marked visual disturbance (Bord and Linden 2008, Lindfield and Das-Bhaumik 2009). In an anterior rupture, the integrity of the globe may be disrupted and ocular contents may be leaking from the eye, which becomes soft due to the reduced intraocular pressure. If the globe has sustained a penetrating injury caused by a fine, sharp fragment, disruption may be less obvious, but subtle signs of anterior rupture, such as a shallow anterior chamber, distorted iris or a focal EMERGENCY NURSE
Figure 3 The skull with, inset, fracture to the orbit
Fracture to orbit Alamy
facial fractures and by compression caused by orbital compartment syndrome, or swelling in the orbit (Guly et al 2006). In major trauma patients, orbital nerve damage can occur acutely as a result of haemorrhage, or as a result of infection or orbital emphysema (Skinner and Driscoll 2013), so clinicians must be alert to an increase in pain, altered pupil reactions and decreased vision. Urgent treatment is required to drain the pressure in the orbit and reverse the crisis.
cataract, may be discernible. If post-traumatic endophthalmitis, or inflammation of the internal layer of the eye, is present, it should be treated as a medical emergency with systemic and intravitreal antibiotics (Durand 2013). The main goal of treatment in the trauma environment is to prevent further damage. If globe rupture is suspected, the eye should not be physically examined any further, a protective shield should be applied and the patient should be referred to an ophthalmologist urgently (Bord and Linden 2008, Lindfield and Das-Bhaumik 2009). Orbital injuries Blunt trauma to the orbital region can result in fracture of the bony orbit, the weakest point of which is the orbital floor. Such blow out fractures can cause the orbital contents to herniate into the antrum. They should be suspected if there is swelling and bruising of the eyelids and periorbital tissues, and if the patients concerned are in pain. Enophthalmos, or the sinking or displacement of the eyeball in the orbit, and exophthalmos, also known as exophthalmia, or bulging of the eye, can also occur as a consequence of a posterior bleed or fracture. Patients with damage to the maxillary nerve can present with diplopia, reduced ocular movement, facial asymmetry and reduced cheek sensation (ACSCT 2008, Skinner and Driscoll 2013). A fracture of the orbit is shown in Figure 3. June 2014 | Volume 22 | Number 3 31
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Art & science | polytrauma Subcutaneous emphysema or subconjunctival haemorrhage can occur if there is a fracture to the ethmoid or maxillary sinus. In such cases, surgery should usually take place only after the swelling has reduced but can be expedited if a blow out fracture has triggered a significant oculocardiac reflex leading to severe bradycardia (Skinner and Driscoll 2013). The Valsalva manoeuvre, in which the patient blocks the nostrils and attempts to exhale through the nose, is contraindicated in those with orbital fracture because it can force air from the sinuses into the surrounding tissues, potentially causing further swelling and globe-content disruption (Greaves et al 2009). Such patients should be advised not to blow their noses or strain during defecation. Burns If the eye has been contaminated by chemicals, urgent action is required to prevent further damage and loss of sight. Topical anaesthetic should be administered before starting vigorous and copious irrigation to remove and neutralise contaminants. Normal saline is an appropriate, readily available solution to use for most chemicals and, if the chemical is unknown, the National Poisons Information Service can be contacted for advice. During irrigation, the eyelid may contract and twitch, and may require manual manipulation. Lenses that deliver a continuous flow of solution to injured eyes can help in these situations but may be contraindicated by the presence of other injuries.
In thermal injuries, the eyelid is injured usually as a result of defensive eye closure, and corneal injury is rare. Burns to the globe, which are also infrequent, require application of a sterile dressing to occlude the eye and referral of the patient to an ophthalmologist (ACSCT 2008).
Conclusion Patients with polytrauma are vulnerable to reduced visual acuity and early detection of eye injuries is vital to improve their long-term outcomes (Georgouli et al 2011). The TARN study states that all patients with major trauma should be checked for eye injuries because, although the prevalence of ocular trauma is low, it increases by up to 7% in patients with facial fractures, especially young adults (Guly et al 2006). If eye injuries are overlooked in major trauma care, treatment can be delayed and the chances of good outcomes reduced, which can have a devastating effect on patients and their families. Nurses should therefore be able to recognise the presence of, or potential for, acute eye injuries in patients with polytrauma, and should have the skills required to provide immediate symptom relief and make the appropriate referrals as necessary.
Find out more The National Poisons Information Service can be contacted at www.npis.org
Online archive For related information, visit our online archive and search using the keywords Conflict of interest None declared
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Constable S, Pirmohamed M (2004) Drugs and the retina. Expert Opinion in Drug Safety. 3, 3, 249.
Balaghafari A, Siamian H, Aligolbandi K (2013) Ocular Trauma: 2 years retrospective study in Sari, Iran. Materia Socio Medica. 25, 4, 230-232.
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Blanch R, Bindra M, Jacks A et al (2011) Ophthalmic injuries in British Armed Forces in Iraq and Afghanistan. Eye Journal. 25, 2, 218–223. Bord S, Linden J (2008) Trauma to the globe and orbit. Emergency Medicine Clinics of North America. 26, 1, 97-123. British National Formulary (2013) British National Formulary No 66. British Medical Association and the Royal Pharmaceutical Society of Great Britain, London. Cillino S, Cascuccio A, Di Pace F et al (2008) A five-year retrospective study of epidemiological characteristics and visual outcomes of patients hospitalised for ocular trauma in a Mediterranean area. BMC Ophthalmology. doi:10.1186/1471-2415-8-6 Cockerham G, Rice T, Hewes E et al (2011) Closed-eye ocular injuries in the Iraq and Afghanistan wars. New England Journal of Medicine. doi: 10.1056/NEJMc1010683.
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Fuller G (2013) Neurological Examination Made Easy. Fifth edition. Churchill-Livingstone, Edinburgh. Georgouli T, Pountos I, Chang B et al (2011) Prevalence of ocular and orbital injuries in polytrauma patients. European Journal of Trauma and Emergency Surgery. 37, 2, 135-140. Greaves I, Porter K, Garner J (2009) Trauma Care Manual. Hodder Arnold, London. Guly C, Guly H, Bouamra O et al (2006) Ocular injuries in patients with major trauma. Emergency Medicine Journal. 23, 12, 915-917. Kanski J (2004) Clinical Ophthalmology: A Synopsis. Butterworth-Heinemann, Edinburgh. Kim J (2000) The use of vital dyes in corneal disease. Current Opinion in Ophthalmology. 11, 4, 241-247. Kuhn F, Morris R, Witherspoon C (2006) Epidemiology of blinding trauma in the United States eye injury registry. Ophthalmic Epidemiology. 13, 3, 209-216.
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