Antiviral Eye Medications

A practical framework for herpetic eye disease

Antiviral management hinges on two questions: which virus (HSV-1/HSV-2 vs. varicella-zoster) and which tissue layer is involved. HSV epithelial keratitis is treated to halt active viral replication and close the epithelial defect. In contrast, HSV stromal, endothelial, or uveitic disease is largely immune-mediated and typically requires a topical steroid with concurrent antiviral coverage to control inflammation while reducing the risk of epithelial reactivation.

Herpes zoster ophthalmicus (HZO) involves the V1 distribution of the trigeminal nerve and requires prompt systemic antiviral therapy, ideally started early after rash onset, to reduce ocular complications and help mitigate post-herpetic neuralgia (PHN). Topical antivirals have a limited role in HZO compared with HSV epithelial disease.

HSV epithelial keratitis: dendritic and geographic ulcers

The hallmark presentation is a dendritic ulcer: a branching epithelial defect with terminal bulbs that stains with fluorescein, often with rose bengal or lissamine green uptake along devitalized margins. Treatment goals are to halt viral replication, promote re-epithelialization, and prevent progression to a geographic ulcer (a larger, ameboid epithelial defect that signals more extensive viral involvement) or deeper stromal disease.

Topical antiviral therapy: Ganciclovir 0.15% gel (Zirgan) is commonly favored for HSV epithelial keratitis due to better epithelial tolerability and less frequent dosing than older agents. It is typically dosed five times daily until the ulcer heals, then tapered to three times daily for an additional week. Trifluridine 1% (Viroptic) remains an alternative when ganciclovir is unavailable or cost-prohibitive, but carries higher surface toxicity risk with intensive dosing (eight to nine times daily) and should be discontinued within 10–14 days of use to avoid epithelial toxicity that can mimic or delay healing.

Oral antiviral therapy: Oral acyclovir, valacyclovir, or famciclovir provide effective tissue levels without added ocular surface toxicity and are increasingly preferred, particularly for patients with pre-existing ocular surface disease, immunocompromised status, or pediatric patients where topical adherence is challenging. The HEDS I trial found no additional benefit to combining oral and topical antivirals in immunocompetent patients, so choosing one route is generally sufficient. An exception may be immunocompromised patients, where acyclovir-resistant HSV prevalence is significantly higher and dual therapy may be warranted.

Epithelial debridement: Gentle debridement of the dendrite with a sterile swab or spatula can be performed adjunctively to reduce viral load before starting antiviral therapy. This may speed healing and reduce antigen exposure to the stroma.

Avoid topical steroids in active epithelial HSV disease (dendritic or geographic ulcers). Steroids can promote viral replication, enlarge the epithelial defect, and worsen outcomes.

HSV stromal, endothelial, and uveitic disease

Stromal keratitis (immune stromal or necrotizing), endothelial involvement (disciform keratitis), and HSV-associated anterior uveitis are driven primarily by inflammatory and immune responses rather than direct viral cytopathic effect. These phenotypes typically require a carefully monitored topical corticosteroid to control inflammation and limit scarring, paired with concurrent oral antiviral coverage to reduce the risk of epithelial reactivation. The HEDS I trial demonstrated that topical corticosteroids reduced stromal inflammation by approximately 68% compared with placebo, but also showed that roughly half of treatment failures occurred within six weeks of discontinuing the steroid, underscoring the importance of a slow, gradual taper.

Because topical antivirals do not penetrate deeply enough to reach the endothelium or anterior chamber reliably, oral antivirals are the preferred route for stromal, endothelial, and uveitic HSV disease. Higher oral dosing may be needed for adequate anterior chamber penetration. Management decisions regarding steroid potency, taper schedule, and antiviral duration depend on severity, location relative to the visual axis, recurrence history, IOP response, and follow-up reliability. Monitor IOP closely, as HSV can cause trabeculitis and steroid-related pressure elevation simultaneously.

Co-management with cornea or uveitis specialists is appropriate when disease is severe, necrotizing, recurrent, or threatening the visual axis.

Herpes zoster ophthalmicus (HZO)

HZO results from reactivation of varicella-zoster virus (VZV) latent in the trigeminal (gasserian) ganglion, with involvement of the ophthalmic (V1) division. Ocular complications can include keratitis (pseudodendrites, nummular infiltrates, mucous plaques, neurotrophic ulcers), anterior uveitis, episcleritis/scleritis, cranial nerve palsies, and post-herpetic neuralgia.

Systemic antiviral therapy is the cornerstone of HZO management. Benefit is greatest when treatment begins early after rash onset. Unlike HSV epithelial disease, topical antivirals are not routinely central to HZO care. Treatment is typically high-dose oral antiviral therapy (valacyclovir, famciclovir, or acyclovir) tailored to renal function, age, and comorbid conditions. Famciclovir and valacyclovir offer simpler dosing schedules than acyclovir, which may improve adherence. Intravenous acyclovir may be needed in severely immunocompromised patients or complicated disease.

Hutchinson sign (vesicles on the tip or side of the nose, indicating nasociliary nerve involvement) increases the likelihood of ocular complications but is not perfectly predictive. All patients with V1 zoster should receive a thorough eye examination regardless of Hutchinson sign status.

Coordinate with primary care, urgent care, dermatology, or neurology for systemic management, pain control, and complex or disseminated cases.

Long-term prophylaxis and the Herpetic Eye Disease Study (HEDS)

The HEDS trials are the landmark evidence base for HSV eye disease management. HEDS II demonstrated that oral acyclovir 400 mg twice daily for 12 months reduced the rate of recurrent ocular HSV disease by approximately 45% overall and cut the recurrence of stromal keratitis roughly in half. Subsequent data have supported valacyclovir 500 mg once daily as a convenient alternative for prophylaxis.

Candidates for long-term prophylaxis include patients with recurrent stromal keratitis or HSV uveitis, frequent epithelial recurrences that impair vision or quality of life, history of HSV in a post-keratoplasty eye (where recurrence can compromise graft survival), and any patient where recurrence would be vision-threatening. The benefit of prophylaxis is greatest in patients with a history of stromal disease, since each recurrence risks additional scarring and visual axis involvement.

Duration of prophylaxis is individualized. Some patients are maintained for years, with periodic reassessment of recurrence risk, renal function, and tolerability. Discontinuation should be gradual and accompanied by patient counseling about recurrence signs.

Neurotrophic keratopathy and metaherpetic disease

A persistent epithelial defect after herpetic keratitis is not always active viral infection. Neurotrophic keratopathy results from corneal nerve damage caused by prior HSV or HZO and presents as a non-healing epithelial defect with smooth, rolled edges, reduced or absent corneal sensation, and a quiet underlying stroma. This is sometimes called metaherpetic disease. The critical distinction is that neurotrophic ulcers are not driven by active viral replication and do not respond to antivirals. Continued antiviral therapy in this setting adds surface toxicity without benefit.

Management shifts to supportive measures: preservative-free artificial tears, autologous serum drops, bandage contact lenses, amniotic membrane transplantation, or tarsorrhaphy depending on severity. Cenegermin (Oxervate), a recombinant nerve growth factor, is FDA-approved for neurotrophic keratitis and can promote epithelial healing in refractory cases. Corneal sensation testing (Cochet-Bonnet esthesiometry or cotton-wisp) is essential to distinguish neurotrophic disease from ongoing infection.

Perioperative antiviral prophylaxis

Any ocular surgery on an eye with a history of herpetic disease, including cataract extraction, corneal transplantation, and refractive procedures, carries a risk of viral reactivation. Surgical trauma and perioperative corticosteroid use are both potential triggers. Antiviral prophylaxis should be strongly considered before and after surgery in patients with a history of HSV or HZO eye disease, particularly while topical steroids are being used postoperatively. In post-keratoplasty patients, long-term prophylaxis is especially important: without oral antiviral coverage, HSV recurrence rates after penetrating keratoplasty have been reported in the range of 30–50% within the first one to two years, and recurrences increase graft rejection risk. See the steroids section for steroid taper considerations and the oral medications page for systemic antiviral context.