What topical antibiotic regimen is recommended for a corneal abrasion, especially if the injury is large, involves a foreign body, or the patient wears contact lenses?

Topical Antibiotic Prophylaxis for Corneal Abrasion

All patients with corneal abrasions must receive topical broad-spectrum antibiotic drops started within 24 hours of injury to prevent bacterial keratitis and ulceration. 1, 2

Standard Antibiotic Regimen

Fluoroquinolone drops (moxifloxacin 0.5% or gatifloxacin 0.5%) are the preferred first-line agents, applied four times daily until complete epithelial healing is confirmed. 3, 2, 4 These fourth-generation fluoroquinolones achieve superior corneal tissue penetration and provide broad-spectrum coverage against both gram-positive and gram-negative organisms. 2, 4

For Simple Non-Contact Lens Related Abrasions:

• Apply fluoroquinolone drops four times daily 3, 2
• Consider adding antibiotic ointment at bedtime for additional lubrication and protection 3, 2
• Use oral acetaminophen or NSAIDs for pain control 3, 2
• Re-evaluate within 24 hours to assess healing and detect early infection 2

For Contact Lens-Related Abrasions:

Mandatory antipseudomonal fluoroquinolone coverage is required due to dramatically increased Pseudomonas keratitis risk. 2, 4 Contact lens wear—especially overnight wear, overwear, inadequate disinfection, or swimming with lenses—creates the highest infection risk. 2, 4

• Prescribe moxifloxacin 0.5% or gatifloxacin 0.5% with more aggressive dosing frequency 3, 2
• Never patch the eye in contact lens wearers—this increases bacterial keratitis risk 1, 3, 2
• Advise complete avoidance of contact lens wear until healing is confirmed by examination 3, 2
• Avoid therapeutic contact lens use due to increased risk of secondary bacterial keratitis 1, 3, 2

Critical Management Principles: What NOT to Do

Eye patching is contraindicated—it does not improve pain, may delay healing, and increases infection risk, especially in contact lens wearers. 3, 2, 4 Multiple well-designed studies demonstrate that patching provides no benefit and may hinder healing. 5

Avoid topical corticosteroids initially as they delay healing and increase infection risk. 3, 2 Never use combination steroid-antibiotic drops as initial therapy. 2 Steroids should only be added after 2-3 days of antibiotic-only therapy if bacterial infection is controlled. 2 Never use corticosteroids in suspected Acanthamoeba, Nocardia, or fungal infections—they worsen outcomes. 2

Do not rub the eye as this worsens the injury and causes further corneal damage. 3, 2

Evidence Quality and Nuances

The American Academy of Ophthalmology guidelines 1, 2 provide the strongest recommendations, though a 2025 Cochrane review 6 found very low certainty evidence for antibiotic prophylaxis effectiveness. However, the Cochrane analysis included older studies (1975-1998) with methodological limitations and did not specifically address high-risk populations like contact lens wearers. 6 In real-world clinical practice, the potential catastrophic consequences of bacterial keratitis—including vision loss—justify prophylactic antibiotic use, particularly when initiated within 24 hours. 1, 2

One older study 6 paradoxically suggested antibiotics may increase infection risk (RR 1.32), but this finding conflicts with established clinical practice patterns and likely reflects study design issues rather than true harm. The guideline consensus strongly supports prophylactic use. 1, 2

Red Flags Requiring Immediate Ophthalmology Referral

Obtain emergent ophthalmology consultation for: 2

• Central infiltrate >2 mm
• Significant stromal involvement or corneal melting
• Corneal infiltrate with suppuration, necrosis, or feathery margins suggesting bacterial keratitis
• High-velocity eye injuries or penetrating trauma
• Irregular pupil after trauma
• Eye bleeding or loss of vision after trauma
• Increasing pain, purulent discharge, or vision changes despite treatment

High-Risk Populations Requiring Enhanced Vigilance

Beyond contact lens wearers, high-risk patients include: 2

• Prior corneal surgery (refractive, cataract, glaucoma surgery, or keratoplasty)
• Chronic ocular surface disease (severe dry eye, entropion, lagophthalmos)
• Immunosuppression or diabetes
• Inadequate blinking or incomplete eyelid closure during sleep

Treatment Escalation for Bacterial Keratitis

If the abrasion progresses to bacterial keratitis with deep stromal involvement, central location, infiltrate >2 mm, hypopyon, or corneal stromal loss: 2

• Obtain cultures before antibiotic initiation
• Initiate loading dose every 5-15 minutes, then hourly dosing
• Consider fortified antibiotics (tobramycin 1.5% + cefazolin 10%) for severe cases
• Fourth-generation fluoroquinolones have demonstrated at least equivalent efficacy to fortified combination therapy 2

Important Caveats

Chronic prophylactic antibiotic use promotes resistant organisms and should only be used for finite treatment periods during the healing phase. 1, 2 Increasing resistance of MRSA and Pseudomonas to fluoroquinolones has been documented, highlighting the need for judicious use. 2, 4

Inadequate blinking or incomplete eyelid closure during sleep significantly impairs healing. 2

Patient education is essential: instruct patients on infection warning signs (increasing pain, discharge, vision changes) and the need for prompt ophthalmologic care if these develop. 2, 4