II. Pathophysiology
- Usually clipped or broken metallic particles
- Particles embed in Cornea with significant force
III. Management
- Check Visual Acuity prior to removal
- Apply Topical Anesthetic to affected eye
- Attempt removal with sterile saline irrigation
- Flow directed toward foreign body may dislodge it
- Attempt removal with damp sterile cotton swab
- Attempt removal with 25 gauge needle tip (or similar spud)
- Brace hand against patient's face
- Position 25 gauge needle parallel to the Corneal surface, approaching from lateral aspect
- Use magnifying loops (or Slit Lamp)
- Gently flick out the foreign body
- Some use battery operated burr tool to remove ocular foreign bodies
- Many ophthalmologists do not recommend this due to the potential for significant Corneal damage and scarring
- If unable to remove
- Patch Eye
- Refer to Ophthalmology
- Prophylactic Topical Antibiotic coverage
- Apply 4 times daily until epithelium heals
- Analgesia for abrasions >3 mm long
- Long acting Cycloplegic (e.g. .25% Isopto Hyoscine)
- AVOID Topical Anesthetics or steroids
- Interfere with epithelium healing
- Reevaluate patient in 24 hours
- Signs of infection
- Adequate healing without signs of Corneal Ulcer
- Fluorescein staining should resolve by 72 hours
IV. Management: Ophthalmology referral indications
- Difficult Foreign Body Removal
- Rust Ring formation at Cornea
- Signs of perforation of globe with foreign body
- Signs of Corneal Ulcer formation
- Haze at base of Corneal defect
- Fluorescein staining persists >72 hours
- Central Corneal defects
V. Complications
- Rust Ring
- Occurs with iron foreign bodies
- Onset in 2-4 hours after embedding
- Complete rust ring forms in 8 hours
- Burr tool is available in many Emergency Departments
- However risk of Vision Loss if Bowman's Membrane is disrupted
- Consider application or Antibiotic ointment (e.g. Erythromycin) and referral to ophthalmology for the next day
- Prolonged foreign body
- Infection risk if embedded >2-4 days
- Results in Corneal Ulceration and scarring
- Requires Ophthalmology referral
- Infection risk if embedded >2-4 days
-
Globe Perforation
- Anterior chamber appears more shallow
- Leakage of fluid from site of foreign body embedding