What are the recommended eye drops for a patient with conjunctivitis (pink eye)?

Eye Drops for Conjunctivitis (Pink Eye)

The recommended eye drops depend entirely on the type of conjunctivitis: for allergic conjunctivitis, use topical antihistamines with mast-cell stabilizing properties (such as ketotifen or olopatadine); for bacterial conjunctivitis, topical antibiotics like polymyxin-bacitracin shorten disease duration but are not always necessary; for viral conjunctivitis, no specific eye drops are required—only supportive care with artificial tears. 1, 2, 3

Determining the Type of Conjunctivitis

The treatment algorithm begins with identifying the etiology based on clinical presentation:

• Allergic conjunctivitis: Bilateral itching is the most consistent and distinguishing feature, often with watery discharge and seasonal pattern 1, 3, 4
• Bacterial conjunctivitis: Mucopurulent discharge with eyelids matted shut upon waking, lack of itching, and no history of prior conjunctivitis strongly suggest bacterial etiology 2, 3, 4
• Viral conjunctivitis: Watery discharge, burning or gritty sensation, often with recent upper respiratory infection or known exposure 2, 3, 4

Treatment by Type

Allergic Conjunctivitis

First-line therapy combines topical antihistamines with mast-cell stabilizing properties, which are more effective than either agent alone. 1

• Ketotifen eye drops: 1 drop in affected eye(s) twice daily, every 8-12 hours, for adults and children ≥3 years 5
• Olopatadine eye drops: Twice daily dosing 1
• These combination agents work for both acute symptoms and chronic prevention 1

Adjunctive measures that enhance efficacy:

• Refrigerated preservative-free artificial tears dilute allergens and inflammatory mediators on the ocular surface 1
• Cold compresses provide symptomatic relief 1
• Wearing sunglasses as a barrier to airborne allergens 1

For inadequately controlled symptoms after 1-2 weeks:

• Add a brief course (1-2 weeks maximum) of topical corticosteroids with low side-effect profile 1
• Critical caveat: If corticosteroids are used, baseline and periodic intraocular pressure measurement is mandatory to screen for glaucoma 1

For severe refractory cases:

• Topical cyclosporine 0.05% (at least four times daily) or tacrolimus can be considered 1
• Cyclosporine 0.1% is FDA-approved specifically for vernal keratoconjunctivitis in children and adults 1

Important pitfall to avoid: Oral antihistamines may worsen symptoms by inducing or exacerbating dry eye syndrome and impairing the tear film's protective barrier 1

Bacterial Conjunctivitis

Topical antibiotics shorten the clinical course but are not mandatory in uncomplicated cases, as most resolve spontaneously in 1-2 weeks. 2, 3, 6

• Polymyxin-bacitracin ointment applied four times daily for 7 days reduces disease duration from approximately 12 days to 9 days and achieves clinical cure in 62% by days 3-5 versus 28% with placebo 6
• By days 8-10, cure rates converge (91% with antibiotic vs 72% with placebo), but bacterial eradication is significantly better with antibiotics (79% vs 31%) 6

When antibiotics are strongly indicated:

• Contact lens wearers (must be treated and referred to evaluate for corneal ulcers) 2, 4
• Conjunctivitis caused by gonorrhea or chlamydia (requires systemic antibiotics in addition to topical therapy) 3, 4
• Neonates with conjunctivitis (requires special pathogen considerations) 2, 4

Delayed antibiotic prescribing (providing a prescription but instructing patients to wait 2-3 days before filling if symptoms don't improve) achieves similar symptom control as immediate prescribing 2

Viral Conjunctivitis

No specific antiviral eye drops are recommended; treatment is entirely supportive. 2, 3, 4

• Artificial tears (preferably preservative-free) provide symptomatic relief 1, 2, 3
• Cold compresses reduce discomfort 1, 2
• Topical antihistamine eye drops can alleviate associated itching 2

One study showed topical dexamethasone 0.1%/povidone-iodine 0.4% reduced disease duration from 11.8 days to 9.4 days, though it caused more stinging than artificial tears 7. However, this is not standard practice, and indiscriminate corticosteroid use should be avoided as it can prolong adenoviral infections and worsen herpes simplex virus infections 1.

Critical infection control: Strict hand hygiene is essential to prevent transmission, as viral conjunctivitis is highly contagious 2, 3

Red Flags Requiring Ophthalmology Referral

Immediate referral is indicated for: 2, 4

• Neonatal conjunctivitis
• Severe eye pain or photophobia
• Decreased vision
• Recent ocular surgery
• Vesicular rash on eyelids or nose (suggests herpes zoster ophthalmicus)
• Immunocompromised state
• Contact lens wearers with suspected bacterial conjunctivitis
• History of rheumatologic disease

Equipment Disinfection

To prevent transmission in clinical settings, tonometer tips should be disinfected with 1:10 sodium hypochlorite (household bleach) solution or EPA-registered hospital disinfectants between patients. 1 Consider deferring intraocular pressure measurement unless absolutely necessary in patients with acute conjunctivitis 1.