What antibiotics are recommended for treating corneal abrasions?

Antibiotic Recommendations for Corneal Abrasions

For corneal abrasions, fluoroquinolones are the recommended first-line topical antibiotics, with moxifloxacin 0.5% or gatifloxacin 0.3% preferred for broad-spectrum coverage, while fortified antibiotics should be reserved for large or visually significant infiltrates. 1

Antibiotic Selection Based on Abrasion Characteristics

Small, Non-Central Abrasions

• First-line options:
  • Moxifloxacin 0.5% - Superior gram-positive coverage
  • Gatifloxacin 0.3% - Superior gram-positive coverage
  • Ciprofloxacin 0.3% (FDA-approved for bacterial keratitis)
  • Ofloxacin 0.3% (FDA-approved for bacterial keratitis)
  • Levofloxacin 1.5% (FDA-approved for bacterial keratitis)
• Dosing: Initial loading dose (every 5-15 minutes) followed by hourly application for central/severe cases 2

Large or Visually Significant Abrasions

• Consider fortified antibiotics, especially if hypopyon is present:
  • Fortified cefazolin 5% (gram-positive coverage)
  • Fortified tobramycin 1.3% (gram-negative coverage)
• Dosing: More frequent application and closer follow-up required 2, 1

Contact Lens-Related Abrasions

• Require antipseudomonal coverage:
  • Fluoroquinolones (particularly fourth-generation)
  • Avoid patching or bandage contact lens
  • Discontinue contact lens wear until complete healing 1

Evidence Supporting Recommendations

The American Academy of Ophthalmology guidelines strongly support fluoroquinolone monotherapy as being equally effective as combination therapy with fortified antibiotics 2. Single-drug therapy using fluoroquinolones has demonstrated efficacy comparable to combination therapy with fortified antibiotics in multiple randomized controlled trials 2.

Fourth-generation fluoroquinolones (moxifloxacin and gatifloxacin) have better gram-positive coverage than earlier generations, making them particularly effective for common corneal pathogens 2. Although widely used, it's important to note that fourth-generation fluoroquinolones are not FDA-approved specifically for bacterial keratitis, while ciprofloxacin 0.3%, ofloxacin 0.3%, and levofloxacin 1.5% have received FDA approval for this indication 2.

Important Considerations and Caveats

• Emerging resistance: Increasing resistance to fluoroquinolones has been observed, particularly among Staphylococcal and Pseudomonas isolates 2. Risk factors for resistance include:

  • Recent fluoroquinolone use
  • Hospitalization
  • Advanced age
  • Recent ocular surgery

• Adjunctive treatments:

  • Cycloplegic agents are recommended to decrease pain from inflammation and prevent synechiae formation 1
  • Topical NSAIDs may provide additional pain control 1
  • Avoid patching as it does not improve healing and may increase infection risk 1, 3

• Follow-up recommendations:

  • Small (<4mm), uncomplicated abrasions with normal vision and resolving symptoms may not require follow-up
  • All other cases should be reevaluated within 24 hours 3
  • Monitor for complete re-epithelialization of the cornea 1

• Treatment duration:

  • Continue antibiotics until complete healing is achieved
  • Discontinue treatment once complete healing is confirmed 1

Special Situations

• Deep or severe keratitis: For deep stromal involvement or infiltrates larger than 2mm with extensive suppuration, use a loading dose followed by frequent applications 2

• High-risk cases: Consider combining treatment with preservative-free aqueous lubricants and viscous gel lubricants 1

• Systemic therapy: May be useful in cases of scleral or intraocular extension of infection 2

Remember that while antibiotic prophylaxis is standard practice for corneal abrasions, a Cochrane review found limited high-quality evidence supporting its efficacy in preventing infection or accelerating epithelial healing 4. Nevertheless, given the potential serious consequences of corneal infection, prophylactic antibiotics remain the standard of care based on expert consensus and clinical experience.