What is the treatment for a corneal ulcer?

Treatment of Corneal Ulcers

Initiate immediate topical fluoroquinolone antibiotic therapy with a loading dose every 5-15 minutes followed by hourly applications for bacterial keratitis, as this represents the cornerstone of treatment and can achieve high tissue levels to prevent vision-threatening complications. 1

Diagnostic Approach

Obtain corneal scrapings before starting treatment using topical anesthetic and a sterile instrument to collect material from the base or periphery of the infection, with samples inoculated directly onto culture media. 1 A nylon-tipped flocked swab shows similar culture positivity rates to traditional methods. 1 Avoid tetracaine as an anesthetic for scraping as it has antimicrobial effects that interfere with culture results. 1

For deep stromal infections or poor treatment response, corneal biopsy may be indicated. 1

Initial Antibiotic Therapy

Topical antibiotics are the preferred treatment method:

• Single fluoroquinolone therapy is as effective as combination fortified antibiotics for most cases. 1
• FDA-approved options include ciprofloxacin 0.3%, ofloxacin 0.3%, and levofloxacin 1.5%. 1
• Fortified topical antibiotics should be considered for large and/or visually significant infiltrates, especially with hypopyon present. 1
• Loading dose: every 5-15 minutes, then hourly for central or severe keratitis. 1

Systemic antibiotics are rarely needed but may be considered when infection extends to adjacent tissues (e.g., sclera) or with impending/frank perforation. 2 Gonococcal keratitis requires systemic therapy. 2

Monitoring Protocol

• Follow daily initially until clinical improvement is confirmed, especially for severe cases (deep stromal involvement or infiltrates >2mm). 2
• If cultures are negative with poor clinical response, stop antibiotics for 12-24 hours then reculture. 1

Adjunctive Therapies

Cycloplegic agents should be used to decrease synechiae formation and reduce pain from anterior segment inflammation. 1

Corticosteroid Use - Critical Timing

Add topical corticosteroids only after at least 2-3 days of progressive improvement with antibiotics, typically after pathogen identification and ruling out fungal infection. 2, 1 The American Academy of Ophthalmology's 2024 guidelines emphasize this conservative approach. 2

Key corticosteroid considerations:

• Use the minimum amount required to control inflammation. 2
• Avoid in Nocardia keratitis - results in poor visual outcomes. 2
• Avoid in fungal keratitis until infection is controlled. 2
• Potential benefit exists for Pseudomonas keratitis and severe cases (ulcers covering central 4-mm pupil or vision of counting fingers or worse). 2
• Earlier addition (within 2-3 days vs. after 4+ days) resulted in 1-line better visual acuity at 3 months in non-Nocardia cases. 2
• Monitor intraocular pressure and watch for cataract formation with long-term use. 2

If patient is already on topical corticosteroids at presentation, reduce or eliminate the regimen until infection is controlled. 2, 1

Surgical Management for Impending Perforation

For corneal thinning or small perforations:

• Cyanoacrylate tissue adhesive is the primary intervention for areas of marked thinning or early descemetocele. 2
• The base must be dry for adhesive to adhere properly. 2
• Works best when the area is small and at the bottom of a crater, not with ballooning descemetocele. 2
• May remain in place for 6+ weeks if applied to a clean, compact base. 2
• Do not use fibrin glue - it biodegrades too rapidly before healing occurs. 2
• Apply bandage contact lenses to prevent glue dislocation and provide comfort. 2

For leaking descemetoceles, inject an air bubble into the anterior chamber to temporarily halt leakage while applying glue. 2

Special Populations and Situations

Contact lens-related keratitis:

• Do not patch the eye or use therapeutic contact lenses for contact lens wearers with corneal abrasions due to increased risk of secondary bacterial keratitis. 1
• Educate about risks: extended wear has 20 per 10,000 incidence vs. 1-2 per 10,000 for daily wear. 2
• Consider switching to daily disposable lenses after resolution. 2

Recurrent bacterial keratitis (more likely S. aureus) may require decolonization of nasopharynx, oropharynx, and ocular surface. 2

Moraxella keratitis requires prolonged treatment duration (mean 41.9 days) despite susceptibility to fluoroquinolones and aminoglycosides. 2

Critical Pitfalls to Avoid

• Never delay culture and sensitivity testing - this leads to ineffective treatment. 1
• Never use corticosteroids in Nocardia or fungal keratitis - outcomes are poor. 2, 1
• Never continue ineffective therapy beyond 7-10 days without clinical re-evaluation and additional laboratory studies. 3
• Chronic topical immunotherapy increases risk of infectious crystalline keratopathy. 2, 1
• Overuse of prophylactic antibiotics promotes resistant organisms. 1

When to Refer/Hospitalize

Immediate ophthalmology referral is required for all corneal ulcers. 4 Hospitalization may be necessary if keratitis is severe, vision-threatening, compliance is unlikely, pain is severe, or patient cannot self-administer drops due to age, mental, or physical disability. 2