Treatment of Bacterial Conjunctivitis
For mild bacterial conjunctivitis, prescribe a 5-7 day course of broad-spectrum topical antibiotic applied 4 times daily, which accelerates clinical resolution, reduces transmissibility, and allows earlier return to school or work. 1, 2
First-Line Antibiotic Selection
Preferred Agents
- Fluoroquinolones (moxifloxacin 0.5%, gatifloxacin 0.5%, or ofloxacin 0.3%) are the preferred empiric choice due to broad-spectrum coverage against common pathogens including Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae. 1, 3, 4
- Aminoglycosides (tobramycin or gentamicin) are effective alternative options with good coverage of common bacterial pathogens. 1, 2
- Polymyxin B/trimethoprim is another acceptable alternative for uncomplicated cases. 1
Alternative When Antibiotics Are Limited
- Povidone-iodine 1.25% ophthalmic solution may be as effective as topical antibiotics and can be considered when access to antibiotics is limited. 1, 2
Dosing Regimen
- Standard dosing: 1 drop every 2 hours while awake (up to 8 times) on Day 1, then 1 drop 2-4 times daily on Days 2-7. 4
- Complete the full 5-7 day course even if symptoms improve earlier. 1, 2
Special Pathogen Considerations Requiring Different Management
Gonococcal Conjunctivitis
- Requires systemic antibiotic therapy—topical treatment alone is insufficient. 1, 2, 3
- Add saline lavage to promote comfort and faster resolution of inflammation. 1
- Daily follow-up is mandatory until complete resolution. 3
- Hospitalization may be necessary for severe cases and is mandatory for neonatal conjunctivitis. 1
Chlamydial Conjunctivitis
- Requires systemic antibiotic therapy (oral azithromycin single dose or tetracycline for 7 days in adults). 1, 3
- Topical therapy alone is inadequate. 1, 2
- For neonates: erythromycin base or ethylsuccinate 50 mg/kg/day divided into 4 doses daily for 14 days. 1
- Consider sexual abuse in children with gonococcal or chlamydial conjunctivitis. 1, 2
MRSA Conjunctivitis
- MRSA has been isolated with increasing frequency (approximately 42% of staphylococcal isolates show methicillin resistance). 3, 5
- May require compounded topical vancomycin based on culture results. 3
- Obtain conjunctival cultures and Gram staining before initiating treatment in moderate to severe cases. 1, 2, 3
When to Obtain Cultures
- Obtain conjunctival cultures and Gram staining for moderate to severe bacterial conjunctivitis, especially if gonococcal infection is suspected. 1, 2, 3
- Severe cases present with copious purulent discharge, pain, and marked inflammation. 3
Follow-Up Protocol
- Advise patients to return if no improvement after 3-4 days of treatment. 1, 2, 3
- Follow-up should include visual acuity measurement and slit-lamp biomicroscopy. 1, 2
- If severe inflammation persists, a brief course of topical corticosteroids may be indicated under ophthalmologic supervision, with baseline and periodic intraocular pressure monitoring. 1
Critical Pitfalls to Avoid
- Do not use topical corticosteroids unless under close ophthalmologic supervision, as they may prolong bacterial shedding and worsen infection. 2, 3
- Reserve fluoroquinolones for appropriate cases to preserve effectiveness and minimize resistance development. 3, 5
- Poor adherence to frequent administration regimens contributes to treatment failure and resistance. 1, 5
- Contact lenses should not be worn during treatment. 4
When to Refer to Ophthalmology Immediately
- Visual loss or decreased visual acuity 1, 2, 3
- Moderate or severe pain 1, 2, 3
- Severe purulent discharge 1, 2, 3
- Corneal involvement (infiltrate, ulceration, opacity, or scarring) 1, 2, 3
- Lack of response to therapy after 3-4 days 1, 2, 3
- Recurrent episodes 1, 2, 3