What are the recommended drops for treating conjunctivitis in an adult patient?

Treatment of Adult Conjunctivitis

For bacterial conjunctivitis in adults, use topical moxifloxacin 0.5% three times daily for 7 days as first-line therapy, while viral conjunctivitis requires only supportive care with artificial tears and cold compresses, and allergic conjunctivitis responds best to topical antihistamines with mast-cell stabilizing properties. 1, 2

Determining the Etiology

The treatment depends entirely on identifying whether the conjunctivitis is bacterial, viral, or allergic 1:

Bacterial conjunctivitis characteristics:

• Mucopurulent or purulent discharge with eyelids matted shut upon waking 3, 4
• Lack of itching 4
• May be unilateral or bilateral 1
• More common in children but occurs in adults 3

Viral conjunctivitis characteristics:

• Watery discharge 3
• Follicular reaction on conjunctiva 1
• Preauricular lymphadenopathy 1
• More common in adults 3

Allergic conjunctivitis characteristics:

• Severe itching is the hallmark symptom 5, 4
• Watery or mucoid discharge 6
• Bilateral presentation 6
• History of allergen exposure 7

Treatment by Etiology

Mild to Moderate Bacterial Conjunctivitis

First-line treatment:

• Moxifloxacin 0.5% ophthalmic solution: one drop three times daily for 7 days 2
• Provides superior gram-positive coverage including activity against some MRSA strains 1
• Achieves 81% complete resolution at 48 hours and 84-94% microbiological eradication 1

Alternative options if moxifloxacin unavailable:

• Ofloxacin 0.3%: one to two drops four times daily for 5-7 days 8
• Other fluoroquinolones (levofloxacin, gatifloxacin, ciprofloxacin, besifloxacin) 1
• No single antibiotic demonstrates superiority, so choice can be based on cost and convenience 5, 1

Important considerations:

• Mild bacterial conjunctivitis is self-limited and resolves spontaneously in immunocompetent adults without treatment 5
• Topical antibiotics provide earlier clinical remission (days 2-5) and allow faster return to work 5, 1
• Povidone-iodine 1.25% ophthalmic solution may be as effective as antibiotics when access is limited 5

Severe Bacterial Conjunctivitis

Characterized by:

• Copious purulent discharge 5
• Marked pain and inflammation 5
• Possible corneal involvement 1

Management approach:

• Obtain conjunctival cultures and Gram staining before treatment if gonococcal infection suspected 5, 1
• Consider MRSA, especially in nursing home residents or those with community-acquired infections 5
• If unresponsive to moxifloxacin within 48-72 hours, consider compounded topical vancomycin for suspected MRSA 1

Gonococcal conjunctivitis requires:

• Systemic antibiotics: ceftriaxone 250 mg IM single dose PLUS azithromycin 1 g oral single dose 1
• Daily monitoring until resolution 1
• Immediate ophthalmology referral 1

Chlamydial conjunctivitis requires:

• Systemic antibiotics: azithromycin 1 g oral single dose OR doxycycline 100 mg oral twice daily for 7 days 1
• Screen for concurrent genital infections and treat sexual partners 1

Viral Conjunctivitis

Adenoviral conjunctivitis (most common):

• No proven effective antiviral treatment exists 1
• Supportive care only: refrigerated preservative-free artificial tears four times daily and cold compresses 1
• Avoid topical antibiotics due to potential adverse effects and resistance 1
• Strict hand hygiene with soap and water to prevent transmission 1

Topical corticosteroids may be considered ONLY in severe cases with:

• Marked chemosis 5, 1
• Severe lid swelling 5, 1
• Epithelial sloughing 5, 1
• Membranous conjunctivitis 5, 1
• Requires close monitoring for elevated intraocular pressure and cataract 5, 1

Herpes Simplex Virus (HSV) conjunctivitis:

• Topical ganciclovir 0.15% gel three to five times daily OR trifluridine 1% solution five to eight times daily 1
• Add oral antivirals (acyclovir, valacyclovir, or famciclovir) 1
• NEVER use topical corticosteroids in HSV without antiviral coverage—they potentiate viral replication and worsen infection 1

Varicella Zoster Virus (VZV) conjunctivitis:

• Oral antivirals: acyclovir 800 mg five times daily for 7 days, valacyclovir 1000 mg every 8 hours for 7 days, or famciclovir 500 mg three times daily for 7 days 5
• Topical antibiotics may be used to prevent secondary bacterial infection from vesicle necrosis 5
• Topical antivirals alone are not helpful 5

Allergic Conjunctivitis

First-line treatment:

• Second-generation topical antihistamines with mast-cell stabilizing properties 5, 1
• Examples include olopatadine, ketotifen, azelastine 5
• Adjunctive measures: cold compresses, refrigerated preservative-free artificial tears, sunglasses as allergen barrier 1

Second-line treatment for persistent symptoms:

• Brief 1-2 week course of low side-effect profile topical corticosteroids (fluorometholone, rimexolone, or loteprednol) 5, 1
• Monitor intraocular pressure and evaluate for cataract if corticosteroids used 5

Severe or refractory cases:

• Topical cyclosporine 0.05% at least four times daily 5
• Cyclosporine 0.1% is FDA-approved specifically for vernal keratoconjunctivitis 5
• Topical tacrolimus 0.03% or 0.1% for cases refractory to other treatments 5

Avoid:

• Chronic use of topical vasoconstrictors—they cause rebound hyperemia 1
• Oral antihistamines may worsen dry eye and exacerbate allergic conjunctivitis 1

Critical Red Flags Requiring Immediate Ophthalmology Referral

• Visual loss or decreased vision 1, 3
• Moderate to severe pain 1, 3
• Severe purulent discharge suggesting gonococcal infection 1, 3
• Corneal involvement (infiltrate, ulcer, opacity, scarring) 1, 3
• Conjunctival scarring 1
• Lack of response to therapy after 3-4 days 1
• Recurrent episodes 1
• History of HSV eye disease 1, 3
• Immunocompromised state 1, 3
• Recent ocular surgery 3
• Vesicular rash on eyelids or nose 3

Common Pitfalls to Avoid

• Never use topical corticosteroids in HSV conjunctivitis without antiviral coverage—this potentiates infection and can cause corneal perforation 1
• Do not use preserved artificial tears more than 4 times daily—preservatives cause ocular surface toxicity 9
• Avoid indiscriminate antibiotic use in viral conjunctivitis—antibiotics induce toxicity and promote resistance 1
• Do not assume copious discharge always means bacterial infection—severe adenoviral conjunctivitis can present similarly 1
• Delayed referral for gonococcal conjunctivitis leads to poor outcomes including corneal perforation and vision loss 1
• Failure to consider sexual abuse in adults with gonococcal or chlamydial conjunctivitis can have serious consequences 1
• Prolonged topical trifluridine use (>2 weeks) causes epithelial toxicity 1

Follow-Up Strategy

• Re-evaluate in 3-4 days if no improvement with bacterial conjunctivitis treatment 1, 10
• Gonococcal conjunctivitis requires daily visits until resolution 1
• If using topical corticosteroids, measure intraocular pressure periodically and perform pupillary dilation to evaluate for cataract 5, 1
• Counsel patients about contagious varieties to prevent spread, emphasizing handwashing and avoiding close contact for 7-14 days in viral conjunctivitis 1