Treatment of Herpes Zoster Ophthalmicus
Initiate oral antiviral therapy immediately—ideally within 72 hours of rash onset—with acyclovir 800 mg five times daily for 7 days, valacyclovir 1000 mg three times daily for 7 days, or famciclovir 500 mg three times daily for 7 days, combined with urgent same-day or next-day ophthalmology consultation. 1
Systemic Antiviral Therapy
The cornerstone of treatment is prompt oral antiviral therapy, which significantly reduces the severity of skin eruption, incidence and severity of late ocular manifestations, and intensity of postherpetic neuralgia. 2 The American Academy of Ophthalmology provides three equivalent first-line options:
- Acyclovir 800 mg orally five times daily for 7 days 1, 3
- Valacyclovir 1000 mg orally three times daily (every 8 hours) for 7 days 1
- Famciclovir 500 mg orally three times daily for 7 days 1
A 7-day course is sufficient; extending treatment to 14 days shows no additional benefit in reducing skin lesions, ocular complications, or postherpetic neuralgia. 2 Treatment is most effective when started within 48 hours of rash onset, though benefit persists if initiated within 72 hours. 1, 4
Ophthalmologic Management
Arrange urgent ophthalmology evaluation within 24 hours to perform comprehensive slit-lamp examination assessing for corneal involvement, anterior uveitis, elevated intraocular pressure, and acute retinal necrosis. 1 Approximately 50% of herpes zoster ophthalmicus patients develop ocular complications requiring ongoing surveillance. 1
Supportive Ocular Care
- Apply non-preserved ocular lubricants (hyaluronate or carmellose drops) every 2 hours throughout acute illness 1
- Perform daily ocular hygiene by ophthalmologist or ophthalmically trained nurse 1
- Consider topical corticosteroid drops (non-preserved dexamethasone 0.1% twice daily) to reduce ocular surface damage 1
- Administer broad-spectrum topical antibiotics (moxifloxacin drops four times daily) if corneal fluorescein staining or ulceration is present 1
Management of Specific Ocular Complications
Stromal Keratitis or Uveitis
Topical corticosteroids may be necessary but must always be used in conjunction with systemic antiviral therapy to prevent viral replication. 1 Use corticosteroids with poor ocular penetration when possible—fluorometholone, rimexolone, or loteprednol—to minimize risk of elevated intraocular pressure and cataract formation. 1 Taper corticosteroids slowly to the minimum effective dose to prevent rebound inflammation. 1
Critical Pitfall to Avoid
Never use topical corticosteroids without concurrent systemic antiviral therapy, as steroids potentiate viral replication and can worsen disease. 1 Additionally, avoid topical trifluridine for more than 2 weeks as it inevitably causes epithelial toxicity. 1
Special Population Considerations
Immunocompromised Patients
Switch to intravenous acyclovir 10 mg/kg every 8 hours for patients with HIV, those receiving chemotherapy, chronic corticosteroids, or transplant recipients. 1 This also applies to patients with disseminated disease (lesions beyond the primary dermatome). 1
Renal Impairment
Exercise caution and adjust antiviral dosing according to renal clearance, as acyclovir half-life and total body clearance are dependent on renal function. 1, 3 Dosage reduction is required for patients with reduced renal function. 3
Geriatric Patients
Acyclovir plasma concentrations are higher in geriatric patients due to age-related changes in renal function; dosage reduction may be required in those with underlying renal impairment. 3 Adults greater than 50 years of age show greater benefit from treatment. 3
Treatment Failure
If patients fail to improve within 7-10 days despite appropriate therapy, suspect acyclovir resistance. 1 Obtain viral culture with susceptibility testing and consider switching to foscarnet 40 mg/kg IV every 8 hours. 1
Prevention of Future Episodes
Once acute symptoms resolve, administer Shingrix (recombinant zoster vaccine) as a 2-dose series, 2-6 months apart, which provides 97.2% efficacy against future episodes. 1 The recombinant zoster vaccine is preferred over the live vaccine due to higher efficacy (96% vs 70%) and is recommended for all immunocompetent adults aged 50 years or older. 1, 5
Expected Outcomes with Treatment
With prompt oral antiviral therapy, late ocular inflammatory complications occur in approximately 29% of patients (versus 50-71% in untreated patients), and only 13% experience postherpetic neuralgia requiring analgesics. 2 Treatment shortens time to lesion scabbing, healing, complete cessation of pain, and reduces duration of viral shedding and new lesion formation. 3