What is the treatment for a patient with herpes zoster ophthalmicus (HZO), a post-shingles infection affecting the eye?

Treatment for Herpes Zoster Ophthalmicus (Post-Shingles Eye Infection)

Initiate oral antiviral therapy immediately with valacyclovir 1000 mg three times daily for 7 days, ideally within 72 hours of rash onset, as this is the primary treatment recommended by the American Academy of Ophthalmology for herpes zoster ophthalmicus. 1, 2

Primary Antiviral Treatment

The cornerstone of HZO management is systemic oral antiviral therapy, which must be started as soon as possible:

First-line options (all for 7 days): 1, 2, 3

• Valacyclovir 1000 mg three times daily (preferred due to convenient dosing)
• Acyclovir 800 mg five times daily
• Famciclovir 500 mg three times daily

Critical timing consideration: Treatment is most effective when initiated within 48-72 hours of rash onset, though later initiation still provides benefit. 1, 2, 4 The 7-day duration is sufficient for immunocompetent patients and should not be extended beyond this period. 5

Renal Dose Adjustments

For patients with impaired renal function, dose adjustments are mandatory to prevent toxicity: 2, 3

• Creatinine clearance 30-49 mL/min: Reduce valacyclovir to 1000 mg twice daily
• Creatinine clearance 10-29 mL/min: Reduce to 1000 mg once daily
• Creatinine clearance <10 mL/min: Reduce to 500 mg once daily

Adjunctive Topical Therapy

Apply topical antibiotics to vesicular lesions to prevent secondary bacterial infection, which can lead to severe complications including cicatricial ectropion. 2 This is particularly important as vesicles undergo necrosis before healing.

Topical antivirals alone are NOT effective for VZV conjunctivitis and should not be used as monotherapy. 1, 2 However, ganciclovir 0.15% gel or trifluridine 1% solution may be added in unresponsive patients as adjunctive therapy only. 2

Corticosteroid Management - Critical Precautions

Topical corticosteroids are absolutely contraindicated during active epithelial viral infection as they potentiate viral replication and worsen the disease. 2

Corticosteroids may only be considered: 2

• For inflammatory complications WITHOUT epithelial disease
• Under direct ophthalmologist supervision only
• Using formulations with poor ocular penetration to minimize intraocular pressure elevation and cataract risk
• For subepithelial infiltrates causing vision impairment, at the minimum effective dose

Special Populations

Immunocompromised patients require more aggressive therapy: 1, 2

• Higher doses and longer treatment duration may be necessary
• Consider intravenous acyclovir 5-10 mg/kg every 8 hours for severe disease or systemic involvement 1
• Patients with chronic or recalcitrant disease may need prolonged treatment with dose adjustments based on clinical response 2

Mandatory Follow-Up Protocol

Schedule follow-up within 1 week of treatment initiation including: 1, 2

• Interval history
• Visual acuity measurement
• Slit-lamp biomicroscopy

For patients on corticosteroid therapy, additional monitoring includes: 2

• Regular intraocular pressure measurements
• Pupillary dilation to evaluate for glaucoma and cataract

Monitoring for Complications

Watch for these potential ocular complications that require ophthalmology referral: 2, 6, 4

• Pseudodendrites
• Keratitis and corneal scarring
• Corneal vascularization
• Iritis/uveitis
• Sectoral iris atrophy
• Secondary glaucoma
• Optic neuropathy (rare)
• Retinitis (rare)

Late sequelae may include: 2

• Dry eye
• Corneal anesthesia with neurotrophic keratitis
• Chronic ocular inflammation requiring ongoing monitoring

Common Pitfalls to Avoid

• Never use topical antivirals as monotherapy - they are ineffective against VZV conjunctivitis 1, 2
• Never apply corticosteroids during active epithelial infection - this worsens viral replication 2
• Do not delay treatment waiting for ophthalmology consultation - start oral antivirals immediately while arranging urgent ophthalmology referral 4
• Do not forget renal dose adjustments - failure to adjust can cause toxicity 2, 3
• Approximately 50% of HZO patients develop ocular disease, with up to 25% developing chronic or recurrent disease - emphasizing the need for close follow-up 7

Prevention

The recombinant zoster vaccine is strongly recommended for all immunocompetent patients aged 50 years and older, with 96% efficacy in preventing herpes zoster and its complications. 2, 7