What are the best eye drops for conjunctivitis (pink eye)?

Best Eye Drops for Pink Eye (Conjunctivitis)

The best eye drops for pink eye depend entirely on the underlying cause: for allergic conjunctivitis, dual-action antihistamine/mast cell stabilizers like olopatadine or ketotifen are first-line; for bacterial conjunctivitis, topical antibiotics like moxifloxacin are indicated; and for viral conjunctivitis, there is no proven effective antiviral treatment, so supportive care with artificial tears is recommended. 1, 2, 3

Determining the Cause

The type of eye drops needed depends on identifying whether the conjunctivitis is:

• Viral: Most common overall cause, typically presents with watery discharge, often bilateral, and highly contagious 4, 5
• Bacterial: More common in children, presents with mucopurulent discharge and eyelids matted shut upon waking 4, 5
• Allergic: Presents with itching (key distinguishing feature), watery discharge, and often bilateral involvement 5, 1

Treatment by Type

Allergic Conjunctivitis

First-line treatment consists of dual-action topical agents (antihistamine + mast cell stabilizer) such as olopatadine, ketotifen, epinastine, or azelastine, which provide rapid symptom relief and prevent recurrent episodes. 1, 6

• These agents are superior to single-action medications because they both treat acute symptoms and provide ongoing protection 1
• Can be stored in the refrigerator for additional cooling relief upon instillation 1
• Refrigerated preservative-free artificial tears should be used concurrently 4 times daily to dilute allergens and inflammatory mediators 1, 6

For severe symptoms not controlled within 48 hours, add a brief 1-2 week course of loteprednol etabonate (low side-effect profile topical corticosteroid). 1, 6

• Requires baseline and periodic intraocular pressure (IOP) measurement plus pupillary dilation to monitor for glaucoma and cataract 1, 6
• Never use corticosteroids for more than 1-2 weeks in this setting 1

Critical pitfalls to avoid:

• Never use punctal plugs—they prevent flushing of allergens from the ocular surface 1, 6
• Avoid oral antihistamines as primary treatment—they worsen dry eye syndrome and impair the tear film 1, 6
• Avoid chronic vasoconstrictor use (>10 days)—causes rebound hyperemia (conjunctivitis medicamentosa) 1, 6

Bacterial Conjunctivitis

Topical fluoroquinolone antibiotics such as moxifloxacin 0.5% (one drop 3 times daily for 7 days) or gatifloxacin 0.5% are effective for bacterial conjunctivitis. 2, 7

• Moxifloxacin covers common pathogens including Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, and Chlamydia trachomatis 2
• Topical antibiotics shorten disease duration and enhance bacterial eradication, though bacterial conjunctivitis is self-limited 8
• Delayed antibiotic prescribing (watchful waiting) has similar symptom control as immediate prescribing and is a reasonable approach 4

Avoid topical antibiotics in viral or allergic conjunctivitis—they can induce toxicity and are not indicated. 1

Viral Conjunctivitis

There is no proven effective antiviral treatment for adenoviral conjunctivitis; management is supportive with preservative-free artificial tears, cold compresses, and topical antihistamines for symptom relief. 3, 4

• Patients should avoid contact with others for 10-14 days from symptom onset in the last affected eye 3
• Strict hand hygiene is essential to prevent transmission 4

For severe adenoviral keratoconjunctivitis with marked chemosis, lid swelling, epithelial sloughing, or membranous conjunctivitis, topical corticosteroids may reduce symptoms and scarring, but require close follow-up. 3

• Povidone-iodine 0.4% with dexamethasone 0.1% has shown promise in reducing viral titers and shortening clinical course 3, 9
• Corticosteroids may prolong viral shedding in animal models, though human data are unclear 3
• Monitor IOP and for cataract formation with prolonged corticosteroid use 3

When to Refer to Ophthalmology

Immediate referral is indicated for: 4

• Severe pain or decreased vision
• Recent ocular surgery
• Vesicular rash on eyelids or nose (suggests herpes)
• Immunocompromised state
• Neonatal conjunctivitis
• History of rheumatologic disease

Special Considerations

For vernal or atopic keratoconjunctivitis (severe chronic allergic forms), topical cyclosporine 0.05% at least 4 times daily or cyclosporine 0.1% (FDA-approved for vernal keratoconjunctivitis) may be necessary to reduce corticosteroid dependence. 3, 1

• Tacrolimus ointment 0.03% can be used for eyelid involvement in patients ≥2 years old 3
• These agents may increase susceptibility to herpes simplex keratitis 3