What is the treatment for zoster ophthalamicus?

Treatment of Herpes Zoster Ophthalmicus

Initiate oral valacyclovir 1000 mg three times daily for 7 days as first-line therapy for herpes zoster ophthalmicus, ideally within 72 hours of rash onset. 1

First-Line Antiviral Therapy

Valacyclovir is the preferred oral antiviral due to superior bioavailability (compared to acyclovir's 10-20% oral bioavailability) and a simpler dosing schedule that improves compliance. 1, 2 The standard regimen is:

• Valacyclovir 1000 mg three times daily for 7 days 1

Alternative regimens with equivalent efficacy include:

• Acyclovir 800 mg five times daily for 7 days 1, 2
• Famciclovir 500 mg three times daily for 7 days 1, 3

Timing is critical: Treatment is most effective when initiated within 72 hours of rash onset, with maximum benefit seen when started within 48 hours. 2, 4 Early antiviral therapy reduces the severity of skin eruption, decreases the incidence of late ocular inflammatory complications from 50-71% (untreated) to approximately 29%, and significantly reduces postherpetic neuralgia. 5, 6

Adjunctive Topical Therapy

Apply topical antibiotics to eyelid vesicles to prevent secondary bacterial infection, which can lead to necrosis, scarring, and cicatricial ectropion. 1, 7 Vesicles on the eyelid margins are particularly vulnerable as they undergo necrosis before healing. 7

Topical antivirals alone are NOT helpful for VZV conjunctivitis and should not be used as monotherapy. 1, 8 However, ganciclovir 0.15% gel or trifluridine 1% solution may be considered as additive treatment in unresponsive patients. 8

Critical Corticosteroid Precautions

Never use topical corticosteroids during active epithelial viral infection as they potentiate viral replication and worsen disease. 8

Corticosteroids may only be considered for:

• Inflammatory complications WITHOUT epithelial disease (e.g., stromal keratitis after epithelial healing, uveitis) 8
• Must be under direct ophthalmologist supervision 8
• Prefer formulations with poor ocular penetration to minimize risk of elevated intraocular pressure and cataract formation 8

Special Populations

Immunocompromised patients require more aggressive treatment with possible dose adjustments and prolonged duration based on clinical response. 1, 8

Adjust dosing in renal impairment: Both acyclovir and valacyclovir require dose reduction based on creatinine clearance to prevent toxicity, as their half-life and clearance are dependent on renal function. 2

Geriatric patients: Acyclovir plasma concentrations are higher due to age-related changes in renal function; dosage reduction may be required in those with underlying renal impairment. 2

Monitoring for Complications

Immediate ophthalmology referral is mandatory for management of varicella zoster virus ocular disease. 1

Monitor for these ocular complications:

• Pseudodendrites and dendritic keratitis 1
• Punctate keratitis, stromal keratitis, corneal scarring, corneal vascularization 1
• Uveitis/iritis and sectoral iris atrophy 1
• Secondary glaucoma 1
• Dry eye and corneal anesthesia with neurotrophic keratitis (late sequelae) 1

Follow-Up Protocol

Schedule follow-up within 1 week of treatment initiation including: 1, 8

• Interval history
• Visual acuity measurement
• Slit-lamp biomicroscopy
• Assessment for resolution of acute symptoms and development of complications

For patients on corticosteroid therapy: Monitor intraocular pressure regularly and perform pupillary dilation to evaluate for glaucoma and cataract. 8

Prevention

Strongly recommend recombinant zoster vaccine (RZV) for all immunocompetent patients aged 50 years and older to prevent herpes zoster and its complications, with 96% efficacy. 9, 8 The vaccine is also recommended for immunocompromised patients 19 years and older. 9

Common Pitfalls to Avoid

• Do not delay treatment waiting for ophthalmology consultation; initiate oral antivirals immediately if herpes zoster ophthalmicus is suspected 4
• Do not use topical antivirals as monotherapy; they are ineffective for VZV conjunctivitis 1, 8
• Do not prescribe corticosteroids without ophthalmologist involvement and never during active epithelial infection 8
• Do not forget to adjust antiviral dosing in patients with renal impairment or elderly patients 2
• Do not assume 7 days is insufficient; studies show no benefit to extending oral acyclovir beyond 7 days 5