Treatment of Bacterial Conjunctivitis with Antibiotic and Steroid Eye Drops
For uncomplicated bacterial conjunctivitis, use topical antibiotics alone (preferably moxifloxacin 0.5% three times daily for 5-7 days) and avoid topical steroids entirely unless you have severe adenoviral conjunctivitis with marked chemosis, lid swelling, epithelial sloughing, or membranous conjunctivitis—and even then, steroids require close monitoring for elevated intraocular pressure and cataract. 1, 2
Initial Assessment: Rule Out Contraindications to Steroids
Before considering any steroid use, you must definitively exclude:
Herpes Simplex Virus (HSV) conjunctivitis: Look for watery discharge, follicular reaction, preauricular lymphadenopathy, or history of HSV eye disease. Topical corticosteroids are absolutely contraindicated in HSV as they potentiate viral replication and worsen infection. 3, 1, 4
Adenoviral conjunctivitis without severe complications: Most cases require only supportive care with refrigerated preservative-free artificial tears four times daily and cold compresses. 1, 4
Gonococcal or chlamydial infection: Severe purulent discharge may indicate gonococcal infection requiring systemic ceftriaxone 250 mg IM plus azithromycin 1 g orally, not topical therapy alone. 1, 5
Treatment Algorithm for Bacterial Conjunctivitis
Mild to Moderate Bacterial Conjunctivitis (Most Common Scenario)
Use antibiotics alone—no steroids needed:
First-line: Moxifloxacin 0.5% one drop three times daily for 5-7 days provides superior gram-positive coverage including some MRSA strains, with 81% complete resolution by 48 hours. 1, 2, 6
Alternative fluoroquinolones: Gatifloxacin 0.5% (Day 1: every 2 hours up to 8 times; Days 2-7: 2-4 times daily) or levofloxacin 0.5% four times daily. 1, 7
Non-fluoroquinolone options: Polymyxin B/trimethoprim four times daily, gentamicin, or tobramycin if cost is a concern, though these show slower resolution (44% cure rate at 48 hours vs 81% with moxifloxacin). 1, 6
Clinical pearls: No single antibiotic demonstrates superiority for uncomplicated cases, so choice can be based on dosing convenience, cost, and local resistance patterns. 1
When Steroids May Be Considered (Rare Scenarios)
Severe adenoviral conjunctivitis with complications:
Topical corticosteroids may be added only if the patient has marked chemosis, severe lid swelling, epithelial sloughing, or membranous conjunctivitis. 3, 1
Use low side-effect profile steroids: fluorometholone, rimexolone, or loteprednol (these have poor ocular penetration and lower risk of elevated IOP or cataract). 3, 4
Initiate only after confirming viral etiology and ruling out HSV. 1
Mandatory monitoring: Measure intraocular pressure periodically, perform pupillary dilation to evaluate for cataract, and taper slowly to minimum effective dose once inflammation is controlled. 3, 4
Re-evaluate within 1 week for severe cases. 3
Corneal subepithelial infiltrates post-adenoviral infection:
If occurring 1+ weeks after initial onset with blurring, photophobia, and decreased vision, topical corticosteroids at minimum effective dose may be considered. Cyclosporine drops 0.05% to 1% are a helpful alternative. 3
Critical Red Flags Requiring Immediate Ophthalmology Referral
- Visual loss 1, 4
- Moderate to severe pain 1, 4
- Severe purulent discharge (suspect gonococcal) 1, 4
- Corneal involvement (infiltrate, ulcer, opacity) 1, 4
- Conjunctival scarring 1, 4
- Lack of response after 3-4 days of appropriate antibiotic therapy 1, 4
- History of HSV eye disease 1, 4
- Immunocompromised state 1, 4
- Neonatal conjunctivitis (requires systemic treatment coordinated with pediatrician) 1, 4
Special Populations and Circumstances
Contact lens wearers:
Reserve fluoroquinolones (ciprofloxacin or moxifloxacin) due to higher risk of Pseudomonas infection. 1, 8
Suspected MRSA:
If no improvement after 48-72 hours of moxifloxacin, consider compounded topical vancomycin, as MRSA isolates are generally resistant to fluoroquinolones and aminoglycosides but susceptible to vancomycin. 1, 5
Pregnant women:
Avoid doxycycline or quinolones; use erythromycin or azithromycin for chlamydial coverage. 1
Children with gonococcal or chlamydial conjunctivitis:
Consider sexual abuse and document diagnosis by standard culture. Treat sexual partners concurrently. 1, 4
Common Pitfalls to Avoid
Never use steroids in HSV conjunctivitis without antiviral coverage—this potentiates infection and can cause corneal perforation. 3, 1, 4
Avoid indiscriminate steroid use in routine bacterial conjunctivitis—most perceived steroid risks (prolonging adenoviral infections, worsening HSV, elevated IOP, cataracts) are associated with long-term use, but short-term use (<2 weeks) still carries risks that outweigh benefits in uncomplicated cases. 1, 9
Do not use topical trifluridine for more than 2 weeks—it inevitably causes epithelial toxicity. 3, 4
Avoid chronic use of topical vasoconstrictors—they cause rebound vasodilation. 4
Do not prescribe antibiotics for viral conjunctivitis—this contributes to unnecessary costs and promotes resistance. 1, 10
Follow-Up Strategy
Bacterial conjunctivitis on antibiotics: Return if no improvement after 3-4 days. 1, 5, 4
Viral conjunctivitis (supportive care only): Return if symptoms persist beyond 2-3 weeks. 4
Patients on topical corticosteroids: Regular follow-up with interval history, visual acuity measurement, IOP measurement, and slit-lamp biomicroscopy. 3, 4