What are the recommended eye drops for treating conjunctivitis?

Eye Drops for Conjunctivitis

For bacterial conjunctivitis, apply broad-spectrum topical antibiotic such as bacitracin or moxifloxacin ophthalmic solution 1-3 times daily for 5-7 days, though most uncomplicated cases are self-limited and delayed prescribing is reasonable. 1, 2

Treatment Algorithm by Etiology

Bacterial Conjunctivitis

Clinical presentation: Mucopurulent discharge with eyelids matted shut upon waking, lack of itching, and no history of prior conjunctivitis strongly suggest bacterial etiology. 3, 4

First-line topical antibiotics:

• Bacitracin ophthalmic ointment applied directly into the conjunctival sac 1-3 times daily for 5-7 days 1
• Moxifloxacin 0.5% ophthalmic solution: one drop in affected eye 3 times daily for 7 days 2
• Delayed antibiotic prescribing achieves similar symptom control as immediate prescribing in uncomplicated cases 4

Important caveat: Most uncomplicated bacterial conjunctivitis resolves spontaneously in 1-2 weeks without treatment. 3 Topical antibiotics primarily shorten duration and allow earlier return to work/school. 3

Special situations requiring systemic antibiotics:

• Gonococcal conjunctivitis: Ceftriaxone 250 mg IM single dose PLUS azithromycin 1 g orally single dose 5
• Chlamydial conjunctivitis: Azithromycin 1 g orally single dose OR doxycycline 100 mg orally twice daily for 7 days 5
• Contact lens wearers: Always treat with antibiotics and refer to ophthalmology to evaluate for corneal ulcers 4, 6

Viral Conjunctivitis

Clinical presentation: Watery discharge, burning/gritty sensation, more common in adults. 4, 6 Adenovirus accounts for 65-90% of viral conjunctivitis cases. 7

Treatment is supportive only:

• Preservative-free artificial tears (frequent application) 8
• Cold compresses 5, 8
• Topical antihistamine eye drops for symptomatic relief 5

Povidone-iodine (PVP-I) for epidemic keratoconjunctivitis:

• PVP-I alone increases resolution of symptoms (RR 1.15) and signs (RR 3.19) during first week compared to artificial tears 7
• PVP-I prevents development of subepithelial infiltrates within 30 days (RR 0.24) 7

Critical pitfall: Avoid topical corticosteroids in viral conjunctivitis as they can prolong adenoviral infections and worsen herpes simplex virus infections. 5

Allergic Conjunctivitis

Clinical presentation: Bilateral itching (most consistent sign), watery discharge, seasonal pattern. 3, 4

Stepwise treatment approach:

1. First-line: Topical antihistamines with mast cell-stabilizing activity 5, 4

   • These combination agents are more effective than antihistamine/vasoconstrictor agents 5
   • Can be refrigerated for additional cooling relief upon instillation 5

2. Adjunctive measures:

   • Preservative-free artificial tears (cooled) to dilute allergens and inflammatory mediators 5
   • Cold compresses 5
   • Avoid eye rubbing 5

3. Severe cases: Brief course (1-2 weeks) of topical corticosteroids with low side-effect profile (fluorometholone, rimexolone, or loteprednol) 5

   • Monitor intraocular pressure and evaluate for cataract with baseline and periodic measurements 5

4. Refractory cases: Topical cyclosporine 0.05% (at least 4 times daily) or tacrolimus 5

Important caveat: Oral antihistamines may worsen symptoms by inducing or exacerbating dry eye syndrome and impairing the tear film's protective barrier. 5

Vernal Keratoconjunctivitis (Severe Allergic Subtype)

For acute exacerbations: Topical corticosteroids are usually necessary to control severe symptoms. 5

Steroid-sparing options:

• Cyclosporine 0.1% (FDA-approved for vernal keratoconjunctivitis in children and adults) 5
• Cyclosporine 0.05% used at least 4 times daily prevents seasonal recurrences 5
• Tacrolimus 0.03% or 0.1% (off-label) 5

Medication-Induced Conjunctivitis

Discontinue the offending agent immediately. 5, 1 Resolution occurs over weeks to months. 5

If severe inflammation present: Brief course of preservative-free topical corticosteroid ointment or cream. 5

Critical warning: Subepithelial fibrosis may continue despite stopping offending medications, particularly with chronic glaucoma medication use. 5

Red Flags Requiring Ophthalmology Referral

Refer immediately for: 1, 4

• Visual loss
• Moderate or severe pain
• Severe purulent discharge
• Corneal involvement
• Conjunctival scarring
• Lack of response to therapy after 2-3 weeks
• Recurrent episodes
• History of herpes simplex virus eye disease
• Immunocompromised status
• Recent ocular surgery
• Vesicular rash on eyelids or nose
• Neonatal conjunctivitis

Infection Control for Viral Conjunctivitis

Patients should be counseled: 5

• Wash hands frequently with soap and water (not sanitizer alone)
• Use separate towels and pillows
• Avoid close contact with others for at least 7-14 days from symptom onset
• Healthcare workers and childcare providers must avoid work during contagious period