What is the treatment for a corneal foreign body?

Treatment for Corneal Foreign Body

Irrigate the eye with sterile saline to flush loose material, remove the foreign body under slit-lamp visualization, prescribe broad-spectrum topical antibiotic prophylaxis (moxifloxacin or gatifloxacin four times daily), and ensure ophthalmology follow-up within 24-48 hours. 1

Immediate Assessment and Red Flags

Before attempting removal, assess for features requiring urgent ophthalmology referral:

• Test visual acuity immediately to establish baseline function and identify acute vision loss 1
• High-velocity mechanisms (grinding, metal work, nailing) carry higher risk of globe penetration and require immediate specialist evaluation 2, 1
• Irregular pupil after trauma indicates penetrating injury requiring emergency referral 2, 1
• Eye bleeding, vision loss, or visible corneal damage (ulceration, haze, opacity, purulent discharge) are critical red flags 1
• Contact lens-related injuries require immediate lens removal and discontinuation 2, 1

Initial Management for Low-Energy Foreign Bodies

For superficial foreign bodies without penetration:

• Do not rub the eye, as this embeds the foreign body deeper and causes corneal abrasion 2
• Irrigate with sterile saline to flush loose material first 1
• Allow natural tears or use tap water/commercial eye wash for initial flushing 2, 1
• Shield the eye with a hard plastic eye shield, paper cup, or plastic cup to prevent unintentional touching 2, 1

Foreign Body Removal Technique

Under slit-lamp biomicroscopy, evaluate:

• Corneal epithelium for defects, location of foreign body (central vs peripheral), depth, and presence of rust ring 3
• Fluorescein staining to identify epithelial defects and differentiate from pooling in areas of thinning 3
• Evert the eyelid to inspect tarsal conjunctiva for retained foreign bodies 3
• Remove the foreign body atraumatically under magnification 4
• Eliminate rust rings if metallic foreign body present, as incomplete removal requires reassessment 1, 4

Post-Removal Treatment Protocol

Mandatory pharmacologic management includes:

• Broad-spectrum topical antibiotic prophylaxis: moxifloxacin or gatifloxacin four times daily 1
• Topical NSAID (ketorolac) for pain, photophobia, and foreign body sensation 1
• Cycloplegic agent (cyclopentolate) to reduce ciliary spasm pain 1
• Oral acetaminophen or NSAIDs for additional pain relief 2, 1

Critical Pitfalls to Avoid

• Never prescribe topical corticosteroids, which promote ulceration from fungal contaminants and can cause corneal melting and perforation 5, 4
• Never prescribe topical anesthetics for home use, as they mask pain from retained foreign bodies or developing corneal ulcers 4
• Test corneal sensitivity in all patients, as corneal anesthesia enhances risk of melting and perforation 5
• Avoid protective patching in contact lens-related injuries due to infection risk 1

Mandatory Follow-Up Requirements

• All patients require ophthalmology follow-up within 24-48 hours to monitor for corneal infection development 1
• For metallic foreign bodies, assess for rust ring formation and ensure complete removal 1
• Instruct patients to return immediately for worsening pain or vision, increasing redness, discharge, or persistent foreign body sensation 1

When to Obtain Cultures

For corneal foreign bodies with associated infiltrates, cultures are recommended when 3:

• Central, large infiltrate (within 3 mm of center and ≥2 mm in size) with significant stromal involvement or melting
• ≥1+ cells in anterior chamber
• History of corneal surgery or trauma with organic matter
• Multiple corneal infiltrates or atypical features