Do antiviral eye drops exist?

Yes, Antiviral Eye Drops Exist and Are FDA-Approved for Specific Viral Eye Infections

Antiviral eye drops are available and FDA-approved for treating viral eye infections, particularly herpetic keratitis caused by herpes simplex virus. The two primary topical antiviral agents used in ophthalmology are ganciclovir 0.15% ophthalmic gel and trifluridine 1% solution 1.

FDA-Approved Topical Antiviral Eye Drops

Ganciclovir 0.15% Ophthalmic Gel (ZIRGAN)

• FDA-approved specifically for acute herpetic keratitis (dendritic ulcers) 1
• Dosing regimen: 1 drop in the affected eye 5 times per day (approximately every 3 hours while awake) until the corneal ulcer heals, then 1 drop 3 times per day for 7 days 1
• Mechanism: Inhibits viral DNA replication by competitive inhibition of viral DNA-polymerase and direct incorporation into viral DNA, causing chain termination 1
• Less toxic to the ocular surface compared to trifluridine, making it preferable for longer-term use 2

Trifluridine 1% Solution

• Used for herpes simplex virus conjunctivitis and keratitis at a dosing of five to eight times per day 2
• Effective in over 90% of patients with dendritic ulcers 3
• Critical limitation: Inevitably causes epithelial toxicity if used for more than 2 weeks 2
• Particularly useful in cases previously unresponsive to other antivirals 3

Clinical Applications by Viral Infection Type

Herpes Simplex Virus (HSV) Conjunctivitis and Keratitis

• Topical ganciclovir 0.15% gel used three to five times per day is a first-line option 2
• Trifluridine 1% solution five to eight times per day is an alternative 2
• Oral antivirals alone may not adequately prevent progression of HSV blepharoconjunctivitis, but adding topical antiviral treatment has proven effective 2
• Follow-up within 1 week should include interval history, visual acuity measurement, and slit-lamp biomicroscopy 2

Varicella-Zoster Virus (VZV) Conjunctivitis

• Topical antivirals alone have NOT been shown to be helpful in treating VZV conjunctivitis 4
• May be used as additive treatment in unresponsive patients when combined with oral antivirals 4
• Primary treatment relies on oral antivirals (acyclovir 800 mg five times daily, valacyclovir 1000 mg three times daily, or famciclovir 500 mg three times daily for 7 days) 2, 4

Adenoviral Conjunctivitis

• No proven effective topical antiviral treatment exists for eradication of adenovirus infection 2
• Off-label use of topical ganciclovir 0.15% ophthalmic gel has shown potential benefit against specific adenovirus serotypes, but further large-scale efficacy studies are needed before definitive recommendations 2
• Povidone-iodine 0.4% alone or combined with dexamethasone 0.1% has demonstrated reductions in viral titers and shortened clinical course, with ongoing clinical trials examining higher concentrations 2

Important Clinical Caveats

When Topical Antivirals Should NOT Be Used Alone

• Topical corticosteroids potentiate HSV epithelial infections and should be avoided in active epithelial disease 2, 4
• Patients should not wear contact lenses during signs or symptoms of herpetic keratitis or during antiviral therapy 1
• Neonates with HSV require prompt systemic consultation as systemic HSV infection is life-threatening 2

Combination Therapy Considerations

• For HSV infections, combining topical antivirals with oral antivirals (acyclovir 200-400 mg five times daily, valacyclovir 500 mg two to three times daily, or famciclovir 250 mg twice daily) provides optimal coverage 2
• Higher doses of oral antivirals may be effective in cases demonstrating resistance to standard therapy 2

Monitoring Requirements

• Patients on prolonged topical antiviral therapy require regular follow-up with visual acuity measurement and slit-lamp biomicroscopy 2
• Watch for development of corneal subepithelial infiltrates, which typically occur 1 or more weeks after onset of viral conjunctivitis 2

Historical Context

Antiviral eye drops have been available since the 1970s-1980s, with idoxuridine, vidarabine, and trifluridine representing earlier generations 3, 5. Ganciclovir represents a newer, better-tolerated option with less ocular surface toxicity 2, 1.