What eye drops are used to treat conjunctivitis?

Eye Drops for Conjunctivitis

The best eye drop for conjunctivitis depends entirely on the underlying cause: topical fluoroquinolones (moxifloxacin or ofloxacin) for bacterial conjunctivitis, topical antihistamines with mast-cell stabilizing properties (olopatadine or ketotifen) for allergic conjunctivitis, and supportive care with artificial tears for viral conjunctivitis. 1, 2

Bacterial Conjunctivitis

For bacterial conjunctivitis, prescribe a 5-7 day course of broad-spectrum topical fluoroquinolone antibiotics. 1, 2

First-Line Antibiotic Options:

• Moxifloxacin 0.5%: 1 drop three times daily for 7 days 3
• Ofloxacin 0.3%: 1-2 drops every 2-4 hours for days 1-2, then four times daily for days 3-7 4
• Other fluoroquinolones (levofloxacin, gatifloxacin, ciprofloxacin, besifloxacin) are equally effective 2

No evidence demonstrates superiority of any specific topical antibiotic over another, so choose based on dosing convenience, cost, and local resistance patterns. 2 Moxifloxacin's three-times-daily dosing offers better compliance than older regimens requiring hourly administration. 3

Special Bacterial Cases Requiring Systemic Treatment:

• Gonococcal conjunctivitis: Ceftriaxone 250 mg IM single dose PLUS azithromycin 1 g oral single dose, with daily ophthalmology follow-up until resolution 1, 2
• Chlamydial conjunctivitis: Azithromycin 1 g oral single dose OR doxycycline 100 mg twice daily for 7 days 1, 2
• Critical pitfall: Topical therapy alone fails for gonococcal and chlamydial infections because these organisms require systemic bactericidal levels 2

Allergic Conjunctivitis

For allergic conjunctivitis, prescribe second-generation topical antihistamines with mast-cell stabilizing properties as first-line therapy. 5, 1, 2

First-Line Allergic Treatment:

• Olopatadine or ketotifen: Apply as directed on product labeling 1, 2
• Adjunctive measures: Cold compresses, refrigerated preservative-free artificial tears four times daily, and sunglasses as allergen barrier 5, 1, 2

Escalation for Severe Allergic Cases:

• If symptoms persist after 1-2 weeks: Add a brief 1-2 week course of low side-effect profile topical corticosteroids 5, 1
• For refractory cases: Consider topical cyclosporine 0.05% (at least four times daily) or cyclosporine 0.1% (FDA-approved for vernal keratoconjunctivitis) 5
• Monitor patients on corticosteroids: Baseline and periodic intraocular pressure measurements and pupillary dilation to screen for glaucoma and cataracts 5, 1

Avoid oral antihistamines as primary therapy because they may worsen dry eye syndrome and impair the tear film's protective barrier, though they can be used adjunctively. 5

Viral Conjunctivitis

For viral conjunctivitis, do NOT prescribe antibiotics—they provide no benefit and may cause toxicity. 1, 2, 6

Supportive Care Only:

• Refrigerated preservative-free artificial tears: Four times daily to dilute viral particles and inflammatory mediators 1, 2
• Topical antihistamines: For symptomatic relief of itching and discomfort 1, 2
• Cold compresses: For comfort 1, 2

Special Viral Cases Requiring Antiviral Treatment:

• Herpes simplex virus (HSV) conjunctivitis: Topical ganciclovir 0.15% gel OR trifluridine 1% solution, with or without oral antivirals (acyclovir, valacyclovir, or famciclovir) 1, 2
• Critical warning: NEVER use topical corticosteroids in HSV conjunctivitis without antiviral coverage, as they potentiate infection 1, 2

Severe Adenoviral Cases:

• For marked chemosis, lid swelling, or membranous conjunctivitis: Consider short course of topical corticosteroids at minimum effective dose, but only with close ophthalmology follow-up for intraocular pressure monitoring 5, 1
• Caution: Corticosteroids may prolong adenoviral shedding 1, 2

Critical Red Flags Requiring Immediate Ophthalmology Referral

Refer urgently to ophthalmology if ANY of the following are present: 1, 2, 6

• Visual loss or decreased vision
• Moderate to severe pain
• Severe purulent discharge (consider gonococcal infection)
• Corneal involvement
• Conjunctival scarring
• Lack of response to therapy after 3-4 days
• Recurrent episodes
• History of HSV eye disease
• Immunocompromised state
• Neonatal conjunctivitis (requires systemic treatment coordinated with pediatrician)

Common Pitfalls to Avoid

• Never use antibiotics indiscriminately for viral conjunctivitis—they cause unnecessary toxicity and do not shorten disease duration 1, 2, 6
• Never use topical corticosteroids without close ophthalmology follow-up—they can cause elevated intraocular pressure, cataracts, prolong adenoviral infections, and worsen HSV infections 5, 1, 2
• Never miss gonococcal conjunctivitis—it can cause corneal perforation within 24 hours and requires immediate systemic antibiotics with daily monitoring 1, 2
• Never treat chlamydial or gonococcal conjunctivitis with topical antibiotics alone—systemic therapy is mandatory, and sexual partners must be evaluated and treated 1, 2
• Advise patients to avoid contact lens wear during any infectious conjunctivitis 2, 6
• Emphasize strict hand hygiene with soap and water to prevent transmission to others or the unaffected eye 1, 2