Ocular foreign body

Background

Ocular foreign bodies are a high-risk chief complaint because of short and long-term threats to vision loss. The main goal is to determine superficial vs. intraocular foreign bodies.

Clinical Features

• Patient history with focus on circumstances/mechanism of symptom onset
  • e.g. use of power tools, projectile weapons, MVCs, metal-on-metal impacts, or high-impact trauma
  • Most common is metal foreign body from hammering
• Ocular foreign bodies may be superficial or intraocular
  • Superficial: embedded in conjunctiva or cornea
    • Eye pain
    • Foreign body sensation
    • Tearing
    • Blurry Vision
  • Intraocular penetration may be asymptomatic initially and present after complications arise (e.g. corneal ulcer)
• Must be careful of multiple foreign bodies

Physical Exam

• Gross ocular inspection
  • Determine open-globe injury e.g. prolapsed intraocular structures, irregular shaped pupil
• Visual acuity test
• Slit lamp exam with and without fluorescein
  • Document size, depth, and location of corneal foreign bodies
  • Signs of deep injury:
    • Inflammation or hemorrhage of anterior chamber
    • Corneal or scleral wounds
    • Corneal infiltrate or hypopyon
    • Iris transillumination
    • Lens opacities
  • Seidel test
  • Evert lids to check for subtarsal foreign bodies
    • Indicated by linear corneal abrasions

Differential Diagnosis

Unilateral red eye

• Nontraumatic
  • Acute angle-closure glaucoma^
  • Anterior uveitis
  • Conjunctivitis
  • Corneal erosion
  • Corneal ulcer^
  • Endophthalmitis^
  • Episcleritis
  • Herpes zoster ophthalmicus
  • Inflamed pinguecula
  • Inflamed pterygium
  • Keratoconjunctivitis
  • Keratoconus
  • Nontraumatic iritis
  • Scleritis^
  • Subconjunctival hemorrhage
• Orbital trauma
  • Caustic keratoconjunctivitis^^
  • Corneal abrasion, Corneal laceration
  • Conjunctival hemorrhage
  • Conjunctival laceration
  • Globe rupture^
  • Hemorrhagic chemosis
  • Lens dislocation
  • Ocular foreign body
  • Posterior vitreous detachment
  • Retinal detachment
  • Retrobulbar hemorrhage
    • Ocular compartment syndrome
  • Traumatic hyphema
  • Traumatic iritis
  • Traumatic mydriasis
  • Traumatic optic neuropathy
  • Vitreous detachment
  • Vitreous hemorrhage
  • Ultraviolet keratitis

^Emergent diagnoses ^^Critical diagnoses

Diagnosis

• Based on patient history with likely mechanism and physical exam

Imaging

• CT scan
  • Detects metal, glass, and stone
  • If negative, consider MRI after CT to make sure no metal
• Ocular ultrasound
  • Contraindicated in setting of open-globe injury
• Plain films only detect 40% of IOFB (intra-ocular foreign bodies), so generally not obtained

Management

• For Superficial ocular foreign body with no signs of open globe injury
  • ED removal from conjunctiva or cornea after topical anesthetic
    • Copious irrigation
    • Cotton-tipped swab soaked in saline
    • 30- to 25-gauge needle under slit lamp
    • Repeat Seidel test to ensure removal did not perforate cornea
    • Irrigate eye profusely post-removal
  • Pain control with topical NSAIDs (e.g. diclofenac or ketorolac) or oral opioids
  • Cycloplegics (e.g. cyclopentolate or homatropine) for photophobia
  • Tetanus booster as needed
  • Consider topical antibiotics for corneal involvement
    • Target gram-positive + pseudomonas (contact wearers)
    • Moxifloxacin – best ophthalmologic penetration
  • Schedule follow-up with ophthalmologist

• Intraocular foreign bodies or concern for open globe injury
  • Emergent ophthalmology consult
  • Prophylactic empiric antibiotics
  • Placement of rigid eye shield
  • Analgesia (oral and topical NSAIDS or opioids) and antiemetics as necessary

• Rust rings
  • Not a true emergency as many will wash out spontaneously
  • May be removed with a 30- to 25-gauge needle as above

Disposition

• Admission and emergent surgical intervention with Ophthalmology for removal

See Also

• Corneal abrasion
• Eye Algorithms (Main)
• Corneal Ulcer
• Conjunctival Abrasion
• Foreign bodies