What is the recommended management, including first‑line therapy and prophylaxis, for herpes simplex virus keratitis in an adult with normal renal function and no drug allergies?

Treatment of Herpes Simplex Virus Keratitis

For HSV epithelial keratitis in adults with normal renal function, initiate combination therapy with topical ganciclovir 0.15% gel 3-5 times daily PLUS oral antiviral therapy (acyclovir 400 mg five times daily, valacyclovir 500 mg 2-3 times daily, OR famciclovir 250 mg twice daily). 1

First-Line Therapy for Epithelial Keratitis

Topical Antiviral Selection

• Ganciclovir 0.15% ophthalmic gel 3-5 times daily is the preferred topical agent due to superior tolerability and significantly less ocular surface toxicity compared to alternatives like trifluridine 1
• Trifluridine 1% solution 5-8 times daily is an alternative topical option, though it inevitably causes epithelial toxicity if used for more than 2 weeks 2, 3
• Most dendritic ulcers heal within 7 days with ganciclovir therapy 1

Mandatory Oral Antiviral Therapy

• Oral antivirals MUST be added to topical therapy—oral therapy alone is insufficient to prevent progression of corneal disease 1
• Dosing options for adults with normal renal function: 1
  • Acyclovir 400 mg five times daily, OR
  • Valacyclovir 500 mg 2-3 times daily, OR
  • Famciclovir 250 mg twice daily

Critical Management Principles

Absolute Contraindications

• Topical corticosteroids are absolutely contraindicated in HSV epithelial keratitis as they potentiate viral replication and worsen infection 2, 1
• This prohibition applies even if inflammation appears significant 1

Follow-Up Protocol

• Schedule follow-up within 1 week including visual acuity measurement and slit-lamp biomicroscopy to monitor treatment response 2, 1

Long-Term Prophylaxis Against Recurrences

Indications for Suppressive Therapy

• Lower doses of oral antivirals are recommended for long-term prophylaxis against recurrent HSV keratitis 2
• After keratoplasty or in cases of severe recurrences, systemic acyclovir 400 mg twice daily for at least 1 year is indispensable 4
• Long-term suppressive oral acyclovir therapy reduces the incidence of recurrent HSV keratitis 3

Prophylactic Dosing

• Acyclovir 400 mg twice daily is the standard prophylactic dose 5, 4
• Duration should be individualized based on recurrence history, with at least 1 year recommended post-keratoplasty 4

Management of Stromal Keratitis (If Present)

When Stromal Involvement Occurs

• Topical corticosteroids ARE indicated for HSV stromal keratitis, but MUST be given together with prophylactic antiviral therapy 6, 3
• This combination shortens the duration of active HSV stromal keratitis 3
• The immune response to the virus contributes to corneal damage in stromal disease, making anti-inflammatory therapy necessary 5, 6

Common Pitfalls to Avoid

• Never use oral antivirals as monotherapy for active epithelial keratitis—topical therapy is essential for corneal disease control 1
• Never prescribe corticosteroids for epithelial disease, even if inflammation appears significant 1
• Consider higher antiviral doses in cases demonstrating apparent resistance to standard therapy 1
• Avoid prostaglandin analogues if concomitant ocular hypertension develops; treat predominantly non-surgically 4

Additional Supportive Measures

• Topical artificial tears (with acyclovir ointment at night if needed) during quiet intervals help limit the tendency toward recurrences 4
• Factors triggering reactivation include stress, illness, immunosuppression, or trauma—patient education about these triggers is important 5