From the Guidelines
Corneal ulcer infections are typically caused by bacteria, and the primary treatment is topical antibiotic therapy.
Etiology
The etiology of corneal ulcer infections can be attributed to various factors, including:
- Contact lens wear, which is the number-one risk factor for microbial keratitis in the United States 1
- Trauma, which is a major risk factor for infection in many parts of the world 1
- Bacterial pathogens, such as Streptococci, Staphylococci, and Pseudomonas aeruginosa, which can cause bacterial keratitis 1
Antibiotic Treatment
The antibiotic treatment for corneal ulcer infections typically involves:
- Topical antibiotic eye drops, which are the preferred method of treatment in most cases of bacterial keratitis 1
- Fluoroquinolones, such as ciprofloxacin 0.3%, ofloxacin 0.3%, and levofloxacin 1.5%, which have been approved by the FDA for the treatment of bacterial keratitis 1
- Fortified topical antibiotics, which should be considered for large and/or visually significant corneal infiltrates, especially if a hypopyon is present 1
- Subconjunctival antibiotic injections, which may be helpful in cases where adherence is questionable or a delay in obtaining fortified antibiotics is anticipated 1
- Systemic therapy, which may be useful in cases of scleral or intraocular extension of infection or systemic infection such as N. gonorrhoeae 1 It's worth noting that corticosteroids should be avoided in cases of suspected Acanthamoeba, Nocardia, or fungus, and their use should be judicious and closely monitored 1. Additionally, emerging treatments, such as topical povidone-iodine and corneal cross-linking, may be effective alternatives or adjuncts to traditional antibiotic therapy 1.
From the Research
Etiology of Corneal Ulcer Infection
- Corneal ulceration and infectious keratitis are leading causes of corneal morbidity and blindness, with infectious causes being among the most frequent and severe 2
- The majority of corneal ulcers are bacterial, but fungus and acanthamoeba are substantial contributors, especially in contact lens-related microbial keratitis (CLMK) 3
- Polymicrobial keratitis, caused by more than one organism, is rare and exceedingly difficult to treat due to variable antibiotic susceptibilities 4
Antibiotic Treatment for Corneal Ulcer Infection
- Topical application with a broad-spectrum antimicrobial remains the preferred method for the pharmacological management of infectious corneal ulcers 2, 3
- Fluoroquinolones may be used as monotherapy for small, peripheral bacterial ulcers 3, 5
- Dual broad-spectrum fortified antibiotics are recommended, with empirical monotherapy treatment with a fluoroquinolone antibiotic being appropriate for certain cases of bacterial keratitis 5, 6
- Intrastromal injections of antibiotics may be necessary to achieve higher drug concentrations at the site of infection, particularly in the case of deep stromal disease refractory to topical therapy 4
- Treatment should be guided by the severity of the clinical presentation, the ophthalmologist's confidence in making the proper diagnosis of bacterial keratitis, and the level of trust in the antibiotic agents chosen for the causative organisms 5