Ocular trauma

Published on 23/06/2015 by admin

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Last modified 22/04/2025

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13.3 Ocular trauma

Introduction

Injury is the leading cause of visual disability and blindness in children and has the following features

Trauma to the eye engenders a marked anxiety reaction in the carer who is always concerned about long term visual impairment. Use a careful and calm approach to enable co-operation so a thorough examination may be performed. Ensure the parent/carer is with the child at all times.

Always consider what may lie beneath an injury that appears to be superficial. Even in an unco-operative child, extensive information can be obtained by observation alone. Uncommonly, mild sedation may be required; however, when there are genuine concerns, referral for general anaesthesia to enable adequate examination is preferred. If gentle restraint has not facilitated examination or a particular procedure, repeated and forcible restraint should not be performed.

Begin by taking a careful history. In addition to aspects of history common to all presentations, ask specifically about existing eye disorders, the mechanism of injury and subsequent events.

Often the injury is unwitnessed or the child may be frightened and so the history may be vague or concealed. Have a high index of suspicion for hidden injury. Specifically ask for visual symptoms of reduction or change in vision. Children are prone to the oculocardiac reflex and a history of bradycardia, nausea, somnolence or syncope strongly suggests a significant injury.

Perform the non-invasive aspects of the examination first. Reassure the patient and carer that you will not hurt them. Dim the room lights if possible, keep the ophthalmoscope light to a minimum. Be systematic and touch last. Importantly, know when to stop and refer.

Document the visual acuity in each eye. Visual acuity testing should be adjusted to the age and ability of the child. Fix and follow testing, ability to reach for a small toy with one or the other eye covered, an Allen chart using pictures (allow the child to identify the pictures closely first), a Tumbling E chart (described as table legs pointing in different directions) or a formal Snellen chart. A difference of two or more lines is significant. Remember the child has a low attention span, so do not insist on them reading every line. If acuity is markedly reduced, use finger counting or light perception at close range.

Follow with a visual inspection. If appropriate, relieve pain with topical anaesthesia early to assist examination.

Examine and document:

Trauma

Lid lacerations

A laceration to the eyelid may be partial or full thickness and may involve the lid margins, canthal tendons, levator complex or canalicular system.

Perform a thorough and complete eye examination to exclude an injury to the globe (see ‘ruptured globe’ below). Pressure exerted by attempts at cleaning and repair may apply pressure to a potentially ruptured globe. Children who are unable to co-operate enough to allow accurate assessment of wound depth should be referred for examination under anaesthesia. If a globe injury is suspected, apply a rigid shield, fast the patient and refer immediately.

The mechanism of injury should be determined to assess the risk of a foreign body (e.g. windscreen shattering), whether a bite (human or animal) and whether significant contamination may have occurred.

Indications for emergency ophthalmologic consultation include:

Wounds requiring referral should be cleaned with normal saline and have foreign material removed as much as possible. Following cleansing, the wound should be covered with a saline soaked dressing, prophylactic antibiotics commenced for bites or significantly contaminated wounds and tetanus status considered.

If the laceration is suitable for repair in the emergency department, the eyebrow should not be shaved as long-term cosmetic alterations may result and the hair direction assists in correct alignment of the wound. Tissue should not be removed, as the good blood supply of the eyelid generally ensures viability. Partial thickness lacerations should be repaired with 6/0 synthetic suture and full thickness lacerations should be repaired in layers. In general, non-absorbable sutures should be removed in 4–7 days. Tissue glue is not advised due to proximity to the lashes and cornea.

Conjunctival haemorrhage, lacerations

Subconjunctival haemorrhage presents as a red eye with a painless collection of bright, smooth blood confined to a sector of the bulbar conjunctiva which is sharply demarcated at the limbus and does not pass beyond the limbus. The visual acuity is normal.

Causes include:

Pain with extraocular movement, reduced vision, hyphaema, pupil abnormality and/or bloody chemosis raise suspicion of a globe injury. A 360 degree subconjunctival haemorrhage should be referred urgently for ophthalmological review as the globe may be ruptured posteriorly. No specific treatment is required for an isolated subconjunctival haemorrhage. The haemorrhage will clear spontaneously within 1–2 weeks.

Conjunctival lacerations present as a red eye with a foreign body sensation and usually a history of trauma. Conjunctival and subconjunctival haemorrhages are often associated. The conjunctival edges can be separated gently with a moist cotton tipped applicator following topical anaesthesia to assess the depth of injury. If the diagnosis is uncertain, refer to ensure a scleral perforation or subconjunctival foreign body is excluded. If the conjunctival laceration is isolated, treatment with antibiotic ointment or drops is required for 4–7 days. They rarely require repair.

Corneal lacerations may be partial (not into the anterior chamber) or full thickness (ruptured globe). Complete examination is required to exclude a penetrating injury of the cornea or sclera. Ensure the anterior chamber is of normal depth and there is no hyphaema. Superficial partial thickness lacerations will heal spontaneously with antibiotic cover; however, daily review is necessary to exclude the development of infection until healing is complete. Deep partial thickness lacerations should be referred for consideration of repair. Seidel’s test can be used (see ruptured globe). For management of full thickness lacerations refer to ruptured globe.

Corneal abrasions: 75% of ED visits are related to corneal abrasions, conjunctival or corneal foreign bodies and conjunctivitis. Corneal abrasions are very painful. Fingernails, sticks or foreign body may be the cause.

They may present with:

The application of a topical local anaesthetic provides temporary pain relief and will assist in allowing the eye to be opened for examination. In a non-compliant child, place a drop at the medial canthus and when the eye is opened, the drops flow in. The non-verbal child may present simply with undifferentiated distress with or without refusal to open the eye and topical anaesthetic may be diagnostic.

Topical anaesthesia should never be provided to the patient for continued installation and home use as this may impair healing, inhibit protective reflexes and permit further injury.

Abrasions may be associated with a foreign body on the lid conjunctiva, which must be everted to be examined fully. An upper lid foreign body is suggested by a linear vertical abrasion. The inner surface of the upper lid is examined by asking the patient to look down, applying a cotton bud to the lid crease and applying light pressure. Use the eyelashes to pull the everted lid over the bud, away and up from the globe. Hold the lashes against the orbital rim to keep the lid everted. To return the lid, release the pressure and ask the patient to look up. The lower fornix is easily inspected by applying downward pressure to the lower lid while the patient looks up.

Diagnose the abrasion by demonstrating a staining defect with fluorescein using either an ophthalmoscope (+12 magnification) or a slit lamp. Use only a small amount of fluorescein as excessive dye can mask the defect. The abrasion will appear bright green when viewed under a blue light.

Conjunctival foreign bodies (palpebral or bulbar) should be removed after topical anaesthesia, with gentle irrigation or a moist cotton tipped swab.

Corneal foreign bodies: Assess for and refer those with an intraocular foreign body immediately (see penetrating injury). Always document the visual acuity. Topical anaesthesia is usually required to relieve pain and blepharospasm, enabling examination.

Removal requires adequate magnification and illumination. Foreign bodies may be removed by irrigation; a cotton tipped applicator or needle removal. Needle removal of a superficial foreign body must occur at the slit lamp and this will require a co-operative child. Approaching from the temporal side, use a 25-gauge needle attached to a 1–3-mL syringe, bevel angled away from the eye, to gently scrape the foreign body from the cornea. Referral should be made if the foreign body is central or deep or if the child is not co-operative. Post removal, complete examination of the eye using fluorescein.

If a rust ring or residual foreign body remains, next day referral should be arranged. Refer patients with central or large abrasions for daily review. Topical antibiotic treatment should be commenced. A topical non-steroidal anti-inflammatory drug (NSAID) provides effective analgesia and if there is severe pain, a cycloplegic (tropicamide 0.5–1%, cyclopentolate 0.5–2%) may be prescribed to relieve ciliary spasm (avoid in infants). Ensure tetanus prophylaxis. Eye patching does not reduce pain or aid healing, may cause difficulty walking in children and thus should be avoided.

Contact lens wearers should be referred for follow up and require pseudomonal coverage (tobramycin or ciprofloxacin). The lens should not be worn until the defect has been healed for a week.

Chemical burns are unusual in childhood, but are potentially very serious. For all chemical burns, irrigation should begin immediately. Anaesthetise the eye (procedural sedation may be required in young children) and then copiously rinse the eye with at least 1–2 litres of Hartmann’s or normal saline (warm if possible) for at least 30 minutes. Use IV tubing connected to the bag of solution and direct the flow from medial to lateral onto the conjunctiva, not cornea. Ensure the fornices are irrigated by everting the lid. A Morgan lens (a moulded lens applied to the eye) allows continuous irrigation if available. Five minutes after irrigation has been completed, check the pH with litmus paper and continue irrigation until a pH > 7 is achieved A urine dipstick can be used (trim with scissors to retain the pH section). Check the pH again 20 minutes after irrigation to ensure there is no rebound fall. Once irrigation is completed, examine for retained foreign bodies. Particulate matter requires removal (moist cotton bud or toothed forceps) and this may require general anaesthesia. Alkali burns (dishwasher liquid, oven cleaner) produce liquefactive necrosis and are often more severe than acid burns.

Once irrigation has been completed, assess injury severity and document acuity. Assess with a slit lamp and fluorescein stain. Moderate or severe burns are suggested by significant epithelial loss, chemosis, corneal oedema or haziness, blanching of the conjunctival vessels or opacification. Refer immediately. All patients require treatment with antibiotic drops/ointment and analgesia ± cycloplegics.

Thermal burns are managed similarly to abrasions. UV keratitis may result from welding, sun lamp exposure or excessive sunlight. The symptoms develop several hours after exposure with pain, tearing and red eye. There are usually bilateral superficial corneal defects seen on fluorescein staining. Treatment is with topical antibiotics ± a cycloplegic.

Traumatic iritis presents with the onset of a dull, aching pain, photophobia, and tearing within 3 days of trauma. Possible signs: small pupil; perilimbal injection of the conjunctiva and pain in the affected eye when a light is shone into either the affected or non-affected eye; reduction in visual acuity; hyphaema. White blood cells and a flare are seen within the anterior chamber when examined under the slit lamp. This is best seen by placing the slit lamp beam at 45 degrees with full intensity and a short narrow slit. The appearance is like dust in a room illuminated with a torch. Refer immediately.

Hyphaema is blood in the anterior chamber and may result from blunt or penetrating trauma. Presents with pain, photophobia, mydriasis/miosis, reduced visual acuity or blurred vision. The red reflex will be intact. If the pupil is dilated, it is important to differentiate between traumatic mydriasis (present only in the affected eye) and an afferent pupillary defect (swinging light test – paradoxical initial dilatation of the affected pupil occurs when light is shone quickly from the unaffected to the affected eye); this may suggest an optic nerve or severe retinal injury. The size may vary from microscopic hyphaema to blood involving the whole anterior chamber. Urgent ophthalmological referral is required for all children. Treatment includes restricted activity, eye shield, anti-emetic, cycloplegic and topical steroid in some children. NSAIDs and aspirin should be avoided. Always consider non-accidental injury. Rebleeding occurs in up to one-third of patients, usually after a few days.

Ruptured globe and penetrating eye injury: A ruptured globe occurs when the integrity of the sclera or cornea is disrupted by blunt trauma or direct perforation. There may be surprisingly few signs. Suspect if there is a peaked pupil (apex of the teardrop points to the perforation), which may be the only clue to occult rupture. Chemosis overlying the laceration, subconjunctival haemorrhage, corneal or scleral laceration, distortion of the anterior chamber (deep or shallow), bubbles in the anterior chamber, extrusion of the intraocular contents, hyphaema, or loss of ocular motility may be indicative. A Seidel’s test can be used if the diagnosis is unclear. Apply a moistened fluorescein strip over the potential site of perforation. Use the blue light of the slit lamp and the leak from a perforation will manifest as a green dilute aqueous stream within the darker, concentrated orange dye.

Once perforation or penetration of the eye is suspected, further emergency department examination is unnecessary.

Rest the child in bed, head up. Protect the eye with a rigid eye shield. If a formal eye shield is unavailable, one can be created from the base of a polystyrene cup. Keep nil by mouth. Commence an anti-emetic and analgesia, ensure tetanus prophylaxis and systemic antibiotic prophylaxis. Contact the ophthalmologist urgently. If an intraocular foreign body or globe rupture is suspected CT will usually be required.

Non-accidental injury may result in any eye injury. A high index of suspicion is required if the injury is inconsistent with the given history or the history is inadequate. Retinal haemorrhage due to inflicted injury is typically seen in the child <1 year and often there are associated injuries.