What are the best antibiotic drops for treating a corneal abrasion?

Best Antibiotic Drops for Corneal Abrasion

For uncomplicated corneal abrasions, prescribe a broad-spectrum fluoroquinolone antibiotic drop such as moxifloxacin 0.5% or ofloxacin 0.3% four times daily to prevent bacterial keratitis. 1

Recommended Antibiotic Options

First-Line Fluoroquinolones

• Moxifloxacin 0.5% is widely used and effective for corneal abrasion prophylaxis, with excellent broad-spectrum coverage against both gram-positive and gram-negative organisms 2
• Ofloxacin 0.3% is FDA-approved for bacterial keratitis and has demonstrated good ocular penetration with activity against common pathogens including Staphylococcus aureus, Pseudomonas aeruginosa, and Streptococcus pneumoniae 3
• Ciprofloxacin 0.3% is another FDA-approved option with proven efficacy 4
• Levofloxacin 1.5% provides equivalent efficacy to ofloxacin with the advantage of higher concentration 5

Dosing Regimen

• Standard prophylaxis: Apply antibiotic drops four times daily until complete epithelial healing is confirmed 5
• Treatment should be initiated within 24 hours of the abrasion to prevent ulceration 1

Special Considerations

Contact Lens-Related Abrasions

• Mandatory antibiotic prophylaxis is required for contact lens wearers due to significantly higher risk of Pseudomonas aeruginosa keratitis 1
• Use fluoroquinolones with strong gram-negative coverage (moxifloxacin or ciprofloxacin) 6
• Never patch the eye in contact lens wearers as this increases risk of secondary bacterial keratitis 1

Role of Tetracycline Ointment

• Tetracycline ointment lacks adequate corneal penetration and should not be used as monotherapy 1
• May be used at bedtime only as adjunctive therapy to fluoroquinolone drops in less severe cases 1
• Antibiotic drops are superior to ointments for achieving therapeutic corneal tissue levels 1

When to Escalate Treatment

Signs Requiring Aggressive Therapy

If the abrasion progresses to bacterial keratitis with any of the following features, escalate immediately:

• Central location or infiltrate >2mm
• Deep stromal involvement
• Presence of hypopyon
• Corneal stromal loss 5

Escalated Treatment Protocol

• Initiate loading dose every 5-15 minutes, then hourly dosing 5
• Consider fortified antibiotics (tobramycin 1.5% + cefazolin 10%) for severe cases 5
• Fourth-generation fluoroquinolones (moxifloxacin, gatifloxacin) may provide better gram-positive coverage than earlier generations 5

Critical Pitfalls to Avoid

Antibiotic Resistance Concerns

• Increasing fluoroquinolone resistance has been documented, particularly in Staphylococcus species (42% methicillin-resistant) and Pseudomonas aeruginosa (up to 52% moxifloxacin resistance in some regions) 5
• Never taper antibiotics below therapeutic dosing as this promotes resistance 7
• Chronic prophylactic use promotes resistant organisms 1

Steroid Use Warning

• Do not use combination steroid-antibiotic drops (like Tobradex) as initial therapy for corneal abrasions 7
• Steroids should only be added after 2-3 days of antibiotic-only therapy, once infection is excluded and epithelial healing has begun 7
• Steroids can mask signs of corneal infection and are contraindicated until fungal keratitis is ruled out 5, 7

Monitoring Requirements

• Next-day ophthalmology follow-up is mandatory to assess healing and detect early infection 1, 8
• If no improvement within 48 hours, modify therapy and consider reculture 7
• Educate patients on infection warning signs: increasing pain, purulent discharge, vision loss 1

Practical Algorithm

1. Confirm diagnosis: Fluorescein staining showing epithelial defect
2. Assess risk factors: Contact lens wear, contaminated trauma, delayed presentation
3. Prescribe: Fluoroquinolone drops (moxifloxacin 0.5% or ofloxacin 0.3%) QID
4. Optional adjunct: Tetracycline ointment at bedtime only
5. Pain management: Oral NSAIDs or acetaminophen (avoid topical NSAIDs long-term) 1
6. Follow-up: 24 hours for reassessment 1, 8