What are the treatment guidelines for herpes zoster ophthalmicus?

Treatment Guidelines for Herpes Zoster Ophthalmicus

Intravenous acyclovir is the recommended first-line treatment for herpes zoster ophthalmicus, with oral valacyclovir or famciclovir as alternatives for less severe cases. 1

Initial Assessment and Diagnosis

Herpes zoster ophthalmicus (HZO) occurs when the varicella-zoster virus reactivates in the ophthalmic division of the trigeminal nerve, representing up to 25% of all herpes zoster cases 2. Key diagnostic features include:

• Periorbital vesicular rash in the distribution of the ophthalmic division of the trigeminal nerve
• Potential ocular manifestations: conjunctivitis, keratitis, uveitis, and ocular cranial nerve palsies
• Risk of permanent sequelae including chronic inflammation, vision loss, and debilitating pain

Treatment Algorithm

Severe Cases (with multi-dermatomal, ophthalmic, visceral, or disseminated involvement)

1. Intravenous acyclovir is the treatment of choice 1
   • Begin treatment within 72 hours of rash onset for maximum effectiveness
   • Continue for a minimum of 7-10 days

Less Severe Cases (typical dermatomal rash)

1. Oral antiviral options (begin within 72 hours of rash onset):

   • Valacyclovir: 1 gram 3 times daily for 7 days 3
   • Famciclovir: 500 mg every 8 hours for 7 days 4
   • Acyclovir: 800 mg 5 times daily for 7 days 5, 6

2. Topical treatment considerations:

   • Topical antivirals alone have not been shown to be helpful in treating VZV conjunctivitis but may be used as additive treatment in unresponsive patients 1
   • Studies have shown that topical acyclovir has no prophylactic value in the management of early HZO compared to oral therapy 7

Adjunctive Therapies

• For patients with corneal epithelial ulceration or membranous conjunctivitis: re-evaluation within 1 week 1
• For subepithelial infiltrates:
  • Mild cases: observation
  • Severe cases (with blurring, photophobia, decreased vision): topical corticosteroids at minimum effective dose 1
  • Consider cyclosporine drops as an alternative for reducing subepithelial infiltrates 1

Special Considerations

Immunosuppressed Patients

• Immunosuppressive therapy should be discontinued in severe cases of VZV infection 1
• May restart immunosuppression after the patient has commenced anti-VZV therapy and skin vesicles have resolved 1

Monitoring and Follow-up

• Follow-up within 1 week for patients with corneal involvement 1, 8
• Monitor for complications including:
  • Corneal subepithelial infiltrates (typically occur 1+ weeks after onset)
  • Secondary bacterial infection of vesicles
  • Postherpetic neuralgia
  • Corneal scarring and vision loss

Prevention

• Recombinant zoster vaccine (RZV) is recommended for immunocompetent adults aged 50 years or older 1
• RZV is preferred over zoster vaccine live (ZVL) due to higher efficacy (96% vs. 70%) 1

Evidence-Based Outcomes

Early antiviral treatment (within 72 hours) has been shown to:

• Reduce the severity of skin eruption 5
• Decrease the incidence and severity of late ocular manifestations 5, 6
• Reduce the intensity of postherpetic neuralgia 9, 5
• Protect against long-term ocular complications 9

One study showed that patients receiving oral acyclovir had significantly less active ocular disease at 6 months compared to placebo (p = 0.01) 9, and another demonstrated reduction in late ocular inflammatory complications from 50-71% in untreated patients to 29.1% in treated patients 5.

Pitfalls and Caveats

• Treatment should be initiated within 72 hours of rash onset for maximum effectiveness 1, 9, 2
• Topical corticosteroids should be avoided in HSV epithelial infections but may be carefully used in HZO with significant inflammation 1
• Patients on prolonged topical corticosteroids require monitoring of intraocular pressure and pupillary dilation to evaluate for glaucoma and cataract 1
• Referral to an ophthalmologist is critical when ophthalmic involvement is present to limit visual morbidity 2