What are the first-line antibiotics and their frequency for treating corneal abrasions?

From the Guidelines

The first-line antibiotics for treating corneal abrasions are typically broad-spectrum topical antibiotics, with fluoroquinolones being the most commonly prescribed, such as moxifloxacin 0.5% (Vigamox) or gatifloxacin 0.3% (Zymar), administered 4 times daily for 5-7 days, as recommended by the most recent study 1.

Key Considerations

• For most uncomplicated corneal abrasions, fluoroquinolones are recommended due to their broad-spectrum coverage and effectiveness against common pathogens, including Pseudomonas aeruginosa, as shown in studies 1.
• Aminoglycosides like tobramycin 0.3% can be used as an alternative, with the same frequency, but may not be as effective against certain gram-positive pathogens.
• Contact lens wearers, who have a higher risk of Pseudomonas infection, should be treated with fluoroquinolones due to their excellent coverage against this pathogen, as noted in 1.
• Antibiotic ointments such as erythromycin or bacitracin-polymyxin B may be used at bedtime in addition to daytime drops, as they provide longer contact time with the corneal surface but can temporarily blur vision.

Treatment Duration and Frequency

• The antibiotic should be continued until the epithelial defect has completely healed, which typically occurs within 24-72 hours for simple abrasions.
• Treatment frequency and duration may need to be adjusted based on the severity of the abrasion and the presence of any underlying conditions, such as contact lens use or previous ocular surgery, as discussed in 1 and 1.

Important Notes

• Prophylactic antibiotics are used primarily to prevent secondary bacterial infection while the epithelium heals, as the corneal abrasion itself is not an infection but a mechanical injury.
• Systemic antibiotics are rarely needed but may be considered in severe cases where the infectious process has extended to adjacent tissues or when there is impending or frank perforation of the cornea, as noted in 1.

From the Research

First-Line Antibiotics for Corneal Abrasions

• The first-line antibiotics for treating corneal abrasions are not clearly defined due to the limited evidence available 2.
• However, some studies suggest that chloramphenicol and fusidic acid are commonly used antibiotics for corneal abrasions 2, 3.
• Other options include moxifloxacin, gatifloxacin, and besifloxacin, which are fourth-generation fluoroquinolones with broad-spectrum activity 3, 4.
• Cefazolin and tobramycin or gentamicin may also be used as initial therapy for suspected microbial corneal ulcers 5.

Frequency of Antibiotic Administration

• The frequency of antibiotic administration for corneal abrasions is not well established, but some studies suggest the following:
  • Chloramphenicol and fusidic acid may be administered three times daily 2.
  • Moxifloxacin may be administered three times daily for 5 days 3.
  • Gatifloxacin and moxifloxacin may be administered hourly for 48 hours and then tapered as per clinical response 4.

Additional Considerations

• The use of antibiotic prophylaxis in corneal abrasions remains unclear due to the low to very low certainty of the available evidence 2.
• The current evidence is insufficient to support any antibiotic regimen being superior to another 2.
• Further research is needed to determine the efficacy and safety of ocular antibiotics in the treatment of corneal abrasions, particularly in high-risk populations 2.