What is the treatment for Herpes zoster ophthalmicus?

Treatment of Herpes Zoster Ophthalmicus

Oral antiviral therapy should be initiated immediately within 72 hours of rash onset as the primary treatment for herpes zoster ophthalmicus, with valacyclovir 1000 mg three times daily for 7 days being the preferred regimen. 1, 2

First-Line Therapy

Oral Antiviral Medications

• Valacyclovir: 1000 mg three times daily for 7 days 1
  • Preferred due to better bioavailability and less frequent dosing
• Acyclovir: 800 mg five times daily for 7 days 2
• Famciclovir: 500 mg three times daily for 7 days 2

Timing of Treatment

• Initiate treatment within 72 hours of rash onset for maximum effectiveness 3
• Early treatment significantly reduces:
  • Severity of skin eruption
  • Incidence of ocular complications
  • Risk of postherpetic neuralgia 4

Management of Ocular Complications

Conjunctivitis

• Topical antibiotics may be used to prevent secondary bacterial infection of conjunctival vesicles 2
• Topical antivirals alone are not effective for VZV conjunctivitis but may be used as adjunctive therapy in unresponsive cases 2

Keratitis/Corneal Involvement

• Refer to ophthalmologist immediately if corneal involvement is suspected 3
• Possible manifestations include pseudodendrites, stromal keratitis, and corneal scarring 2

Uveitis/Intraocular Inflammation

• May require topical corticosteroids under ophthalmological supervision 2
• Must be used in conjunction with adequate systemic antiviral coverage 2

Special Populations

Immunocompromised Patients

• May require more aggressive treatment and longer duration 2
• Consider higher doses of oral antivirals in resistant cases 2

Patients with Renal Impairment

• Adjust dosage based on creatinine clearance 1
• For valacyclovir, modify dosing according to renal function:
  • CrCl 30-49 mL/min: Adjust dose
  • CrCl 10-29 mL/min: Further dose reduction
  • CrCl <10 mL/min: Significant dose reduction 1

Follow-Up Care

Monitoring Schedule

• Initial follow-up within 1 week of treatment initiation 5
• Assessment should include:
  • Interval history
  • Visual acuity measurement
  • Slit-lamp biomicroscopy 2

Long-Term Management

• Monitor for chronic sequelae including:
  • Dry eye
  • Corneal anesthesia with neurotrophic keratitis
  • Post-herpetic neuralgia 2
• Patients with chronic disease may require prolonged treatment with dose adjustment according to clinical response 2

Common Pitfalls and Caveats

1. Delayed Treatment: Initiating antivirals after 72 hours significantly reduces efficacy but should still be considered if active lesions are present 3

2. Inadequate Dosing: Using insufficient doses or duration can lead to treatment failure and increased risk of complications 2

3. Missing Ocular Involvement: Always perform a thorough eye examination as ocular complications may develop without obvious symptoms initially 3

4. Inappropriate Steroid Use: Avoid topical corticosteroids without adequate antiviral coverage as this may worsen viral replication 2

5. Failure to Adjust for Renal Function: Not adjusting antiviral doses in patients with renal impairment can lead to toxicity 1

While one study comparing valacyclovir to acyclovir showed similar efficacy, valacyclovir offers better bioavailability and less frequent dosing, making it the preferred option for most patients 6, 7. Recent evidence suggests that oral valacyclovir may be effective even in cases with optic nerve involvement that traditionally required intravenous therapy 7.