Treatment of Bacterial Conjunctivitis
Topical moxifloxacin 0.5% administered three times daily for 7 days is the recommended first-line treatment for bacterial conjunctivitis due to its superior efficacy and faster resolution of symptoms compared to other antibiotics. 1
Diagnosis and Classification
Before initiating treatment, it's important to differentiate bacterial conjunctivitis from other forms:
- Bacterial conjunctivitis: Characterized by mucopurulent discharge and matted eyelids
- Viral conjunctivitis: Presents with watery discharge and often upper respiratory symptoms
- Allergic conjunctivitis: Distinguished by severe itching and history of allergies 1
Treatment Algorithm
First-line Treatment
- Moxifloxacin 0.5%: Three times daily for 7 days 1
Alternative Options
- Gatifloxacin 0.5%:
- Day 1: One drop every two hours while awake (up to 8 times)
- Days 2-7: One drop 2-4 times daily 2
- Other effective options:
- Gentamicin
- Tetracycline
- Ofloxacin 1
Special Situations
Gonococcal conjunctivitis:
- Requires systemic antibiotics (ceftriaxone) in addition to topical therapy
- Obtain conjunctival cultures and Gram staining 1
Chlamydial conjunctivitis:
- Requires systemic antibiotics (azithromycin or doxycycline) 1
Pregnant women:
- Avoid doxycycline, quinolones, or tetracyclines
- Use erythromycin or amoxicillin for chlamydial infection 1
Children:
- Same topical antibiotics as adults
- Adjust dosage for systemic therapy when needed 1
Evidence for Antibiotic Treatment
The Cochrane Review found that topical antibiotics improve both early (days 2-5) and late (days 6-10) clinical and microbiological remission rates compared to placebo 3. However, it's worth noting that by days 6-10,41% of cases had resolved spontaneously without antibiotics 3.
Fourth-generation fluoroquinolones like moxifloxacin and gatifloxacin have better coverage of gram-positive pathogens than earlier generation fluoroquinolones 4. Gatifloxacin is specifically FDA-approved for bacterial conjunctivitis caused by susceptible strains of common pathogens including Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, and Haemophilus influenzae 2.
Prevention and Hygiene
To prevent spread of infection:
- Practice frequent handwashing with soap and water
- Avoid sharing towels, washcloths, and pillows
- Avoid touching or rubbing eyes
- Change pillowcases frequently during infection 1
When to Refer
Immediate referral to ophthalmology is necessary for:
- Visual loss
- Moderate to severe pain
- Severe purulent discharge
- Corneal involvement
- Lack of response to therapy within 48-72 hours
- Recurrent episodes 1
Return to Work/School
Patients can typically return to work or school after 24 hours of antibiotic treatment 1.
Common Pitfalls to Avoid
- Overuse of antibiotics for viral conjunctivitis
- Prolonged use of corticosteroids without ophthalmology supervision
- Failure to recognize potentially serious causes of conjunctivitis
- Inadequate hygiene education
- Delayed referral for severe or non-responsive cases 1
Emerging Concerns
The prevalence of resistance to fluoroquinolones is increasing, particularly with methicillin-resistant S. aureus 1. This underscores the importance of appropriate antibiotic selection and completing the full course of treatment.