Eyelid trauma
Periocular haematoma
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A ‘black eye,’ consisting of a haematoma (focal collection of blood) and/or periocular ecchymosis (diffuse bruising) and oedema, is a very common result of blunt injury and is generally innocuous.
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It is important to exclude serious associated damage to the eyeball or orbital structures, particularly occult orbital roof fracture (subconjunctival haemorrhage without a visible posterior limit may be an indicator), and basal skull fracture (may give bilateral ring haematoma—‘panda eyes’; Fig. 21.1 ).
Fig 21.1
Laceration
Repair should be by direct closure whenever possible, because this affords the best functional and cosmetic result.
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Marginal lacerations: sutured with perfect alignment to prevent notching.
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Extensive tissue loss: may require a major reconstructive procedure as following tumour resection.
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Canalicular lacerations ( Fig. 21.2 ): should be repaired within 24 hr with bicanalicular (e.g. Crawford) or monocanalicular (e.g. Mini Monoka) silicone stenting.
Fig 21.2
Blow-out orbital floor fracture
Pathogenesis: sudden increase in orbital pressure due to an impacting object ( Fig. 21.3 ). The fracture most frequently involves the relatively weaker floor of the orbit along the thin bone covering the infraorbital canal. Occasionally, the orbital wall, the rim, and/or adjacent facial bones may be fractured.
Fig 21.3
Diagnosis
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Periorbital: (a) ecchymosis, (b) oedema, and (c) occasionally subcutaneous emphysema.
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Infraorbital nerve anaesthesia: (lower lid, cheek, side of nose, upper lip, upper teeth, gums) is common.
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Mechanisms of diplopia: (a) restriction due to haemorrhage and oedema, (b) mechanical entrapment of extraocular muscle or adjacent connective tissue within the fracture, with diplopia typically occurring in both up- ( Fig. 21.4a ) and downgaze ( Fig. 21.4b ), and (c) direct injury to an extraocular muscle (negative forced duction test).
Fig 21.4
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Enophthalmos: in severe fracture.
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Globe damage: uncommon but should be excluded.
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CT: with coronal views for fracture evaluation ( Fig. 21.4c ).
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Hess test: for monitoring diplopia.
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Initial treatment
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Oral antibiotics: no nose blowing because infected sinus contents may be forced into the orbit.
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Ice packs and nasal decongestants: for swelling.
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Systemic steroids: occasionally required for severe oedema, especially if there is optic nerve compromise.
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Subsequent treatment
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Aims: prevention of permanent diplopia and/or cosmetically unacceptable enophthalmos.
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Surgery not required: (a) fractures involving up to one-third of the orbital floor, (b) little or no herniation, (c) no significant enophthalmos, and (d) improving diplopia.
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Surgery within 2 weeks: (a) fractures with entrapment of orbital contents, (b) enophthalmos greater than 2 mm, and (c) significant diplopia.
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Urgent surgery: (a) early marked enophthalmos, and (b) ‘white-eyed’ fracture subgroup with acute trap-door incarceration of herniated tissue. This requires urgent repair to avoid permanent neuromuscular damage; patients are typically younger than 18 years of age with little visible external soft tissue injury, and CT signs may be subtle.
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Surgical technique: (a) transconjunctival or subciliary approach, (b) removal of entrapped orbital contents, and (c) defect is covered with a synthetic patch (e.g. silicone; Fig. 21.5 ).
Fig 21.5
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Trauma to the globe
Definitions
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Closed injury: commonly due to blunt trauma; the corneosclera is intact.
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Open injury: full-thickness wound of the corneoscleral envelope.
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Rupture: full-thickness wound caused by blunt trauma; the globe gives way at its weakest point, which may not be at the site of impact.
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Laceration: full-thickness defect in the eye wall produced by a tearing injury, usually due to a direct impact.
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Incised injury: caused by a sharp object such as glass or a knife.
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Penetrating injury: single full-thickness wound, usually caused by a sharp object, without an exit wound; may be associated with an intraocular foreign body.
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Perforating injury: full-thickness entry and exit wounds, usually caused by a missile.
Imaging
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Plain radiographs: may be taken when a foreign body is suspected.
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CT: superior to plain radiographs in detection and localization of foreign bodies.
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MR: more accurate than CT in assessment of the globe such as detection of an occult posterior rupture, although not for bony structures. MR should never be performed if a ferrous foreign body is suspected.
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US: may identify an intraocular foreign body, globe rupture, suprachoroidal haemorrhage, and retinal detachment.
Blunt trauma
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Corneal abrasion: breach of the epithelium, demonstrated by fluorescein staining ( Fig. 21.6 ).
Fig 21.6
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Corneal oedema: folds in Descemet membrane and stromal thickening ( Fig. 21.7 ).
Fig 21.7
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Hyphaema: blood in the anterior chamber with a horizontal ‘fluid level’ pattern ( Fig. 21.8 ).
Fig 21.8
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Pupillary damage: (a) compression of the pupillary margin against the lens results in imprinting of pigment (Vossius ring; Fig. 21.9 ), (b) damage to the iris sphincter may cause mydriasis, and (c) radial tears in the pupillary margin ( Fig. 21.10 ).
