In a 30-year-old man with a unilateral vesicular rash over the left V1 distribution (forehead and periorbital area) diagnosed as herpes zoster ophthalmicus and started on oral acyclovir, what is the next essential management step?

Urgent Ophthalmology Referral for Slit-Lamp Examination

This patient requires immediate ophthalmology referral (within 24 hours) for comprehensive slit-lamp biomicroscopy to evaluate for ocular involvement, as herpes zoster ophthalmicus carries a high risk of vision-threatening complications including keratitis, uveitis, and secondary glaucoma. 1

Why Ophthalmology Referral is Essential

The presence of vesicular rash in the V1 distribution (forehead and periorbital area) indicates herpes zoster ophthalmicus, which affects the eye in up to 50-71% of untreated cases and can cause permanent vision loss. 2 Even though oral acyclovir has been initiated appropriately, this does not eliminate the need for specialized ocular examination because:

• Ocular complications occur frequently despite systemic antiviral therapy, with late inflammatory complications developing in approximately 29% of treated patients 2
• Early detection is critical for preventing permanent sequelae including corneal scarring, chronic uveitis, sectoral iris atrophy, and secondary glaucoma 1
• Slit-lamp examination is required to identify early keratitis (punctate or pseudodendritic), anterior chamber inflammation, elevated intraocular pressure, and corneal involvement that cannot be detected by routine physical examination 1

Specific Ophthalmologic Assessment Needed

The ophthalmologist should perform:

• Visual acuity measurement to establish baseline function 1
• Slit-lamp biomicroscopy with fluorescein staining to detect pseudodendritic keratitis (non-excavated, unlike HSV's excavated dendrites), punctate epithelial keratitis, stromal involvement, and anterior chamber inflammation 3, 1
• Intraocular pressure measurement to screen for acute angle-closure or inflammatory glaucoma 1
• Dilated fundus examination if there is concern for posterior segment involvement (retinitis) 3

Additional Management Considerations While Awaiting Ophthalmology

Topical Antibiotic Application

• Apply topical antibiotic ointment to vesicular eyelid lesions to prevent secondary bacterial infection and reduce risk of severe conjunctival scarring and cicatricial ectropion 1

Critical Corticosteroid Warning

• Never initiate topical corticosteroids during active epithelial viral infection, as they potentiate viral replication and worsen disease 1
• Corticosteroids may only be considered later by the ophthalmologist for inflammatory complications (stromal keratitis, uveitis) after epithelial healing is confirmed 1

Verify Antiviral Dosing

• Confirm the acyclovir dose is 800 mg five times daily for 7-10 days (not the lower HSV dosing of 400 mg five times daily) 1, 2
• Alternative preferred regimen is valacyclovir 1000 mg three times daily for 7 days, which has superior bioavailability though similar efficacy 1, 4
• Adjust dose for renal impairment based on creatinine clearance to avoid nephrotoxicity 1

Follow-Up Protocol

Initial Follow-Up (Within 1 Week)

Schedule ophthalmology follow-up within 1 week of treatment initiation to assess:

• Interval history focusing on pain, visual changes, and new ocular symptoms 1
• Visual acuity measurement 1
• Slit-lamp biomicroscopy to detect early complications 1

Long-Term Surveillance

Patients require ongoing monitoring for:

• Late sequelae including dry eye, corneal anesthesia leading to neurotrophic keratitis, chronic uveitis, and post-herpetic neuralgia 1
• Subepithelial infiltrates that typically appear one or more weeks after disease onset 1
• Cicatricial lid complications from scarring that may require surgical correction 1

Common Pitfalls to Avoid

• Do not delay ophthalmology referral based on absence of visual symptoms—ocular involvement can be asymptomatic initially 5
• Do not use topical antivirals alone—they are ineffective as monotherapy for VZV and should only be added if systemic therapy fails 1
• Do not assume treatment beyond 72 hours is futile—antiviral therapy initiated up to 7 days after rash onset still provides prophylactic benefit against ocular complications 6