Ocular Antiviral Therapy: Clinical Overview
Recognizing and Treating Viral Eye Disease
Viral infections of the eye, particularly herpes simplex keratitis and herpes zoster ophthalmicus, can rapidly damage the cornea and threaten long term visual acuity. Early recognition of dendritic or geographic epithelial lesions, dermatomal rashes, or neuropathic pain allows prompt antiviral initiation and reduces scarring, neurotrophic changes, and post herpetic neuralgia. Optometrists should maintain a low threshold for therapy when clinical findings and history suggest herpetic involvement, especially in immunocompromised or elderly patients.
Topical Versus Systemic Antivirals
Topical agents such as ganciclovir 0.15% gel deliver high concentrations directly to the corneal epithelium and are effective for epithelial herpes simplex lesions. Systemic drugs like acyclovir, valacyclovir, and famciclovir achieve therapeutic levels in the trigeminal ganglion and adnexal tissues, which is critical for stromal disease, uveitis, or herpes zoster involvement. Many cases benefit from oral therapy alone or in combination with topical treatment to shorten disease duration and lower recurrence risk.
Dosing Strategies and Duration of Therapy
Initiate oral antivirals with loading doses that match disease severity and reduce to maintenance levels as lesions resolve. Typical courses for epithelial herpes simplex can run 7 to 10 days, while herpes zoster ophthalmicus often needs 7 to 14 days with dosing adjusted for renal function and age. Long term prophylaxis with low dose oral acyclovir or valacyclovir can reduce recurrence in patients with frequent episodes or after corneal transplantation. Document start dates and plan follow up to ensure epithelial closure and symptom resolution before tapering.
Steroids, Inflammation, and Co Management
Topical steroids can be vision saving in stromal keratitis and uveitis but must be paired with adequate antiviral coverage to prevent viral replication. Do not use steroids in active epithelial disease. Coordinate with a corneal specialist when stromal involvement, endotheliitis, or neurotrophic complications develop. Closely monitor intraocular pressure and corneal integrity during steroid use and taper gradually once inflammation quiets to avoid rebound.
Safety, Contraindications, and Patient Counseling
Screen for renal impairment, pregnancy status, and drug allergies before prescribing oral antivirals. Adjust dosing in patients with reduced creatinine clearance to avoid neurotoxicity and gastrointestinal effects. Educate patients about adherence, hydration, and recognizing warning signs such as increased pain, photophobia, or decreased vision. For herpes zoster, stress the value of early therapy within 72 hours of rash onset and discuss the role of vaccination in reducing future episodes.
Follow Up, Recurrence Prevention, and Documentation
Reevaluate within a few days for epithelial disease and sooner if symptoms worsen. Record lesion size, location, and depth to track response. Consider prophylactic therapy for recurrent herpes simplex keratitis or after ocular surgery in known carriers. Keep dosing tables, contraindication notes, and taper protocols updated to reflect current guidelines and resistance patterns so future visits can reference accurate, consistent information.