Treatment of Double Vision Following Shingles
For double vision (diplopia) following shingles, initiate oral valacyclovir 1 gram three times daily or famciclovir 500 mg three times daily immediately, continuing until all lesions have completely scabbed, with urgent ophthalmology referral to assess for cranial nerve involvement and potential vision-threatening complications. 1
Immediate Antiviral Therapy
- Start antiviral treatment immediately upon diagnosis, even if beyond the typical 72-hour window, as facial and ophthalmic zoster requires urgent intervention to prevent permanent neurological and visual complications 1
- Valacyclovir 1000 mg three times daily for 7-10 days is the preferred first-line agent due to superior bioavailability and less frequent dosing compared to acyclovir 1
- Famciclovir 500 mg three times daily is equally effective and represents an appropriate alternative 1
- Continue treatment until all lesions have completely scabbed, not just for an arbitrary 7-day period—this is the critical clinical endpoint 1
Escalation Criteria for Intravenous Therapy
Double vision following shingles suggests cranial nerve involvement (likely cranial nerves III, IV, or VI), which may indicate more severe disease requiring escalation:
- Switch to intravenous acyclovir 10 mg/kg every 8 hours if there is suspected CNS involvement, severe ophthalmic disease, or if the patient is immunocompromised 1, 2
- Disseminated herpes zoster (multi-dermatomal involvement, visceral complications) mandates IV acyclovir 1, 3
- Continue IV therapy for a minimum of 7-10 days and until complete clinical resolution 3
Urgent Ophthalmology Consultation
- Immediate ophthalmology referral is essential when shingles affects the face, as ophthalmic involvement can lead to keratitis, anterior uveitis, or acute retinal necrosis—devastating complications requiring specialized management 2
- Cranial nerve palsies causing diplopia require assessment for extent of neurological involvement 2
- Monitor for vision-threatening complications including decreased visual acuity, eye pain, photophobia, or red eye 2
Special Considerations for Immunocompromised Patients
- If the patient is immunocompromised (HIV, cancer, transplant, chronic steroids), start IV acyclovir immediately due to high risk of dissemination and CNS complications 1, 3
- Consider temporary reduction of immunosuppressive medications in consultation with the prescribing specialist 1, 3
- Immunocompromised patients may require treatment extending well beyond 7-10 days as lesions develop over longer periods (7-14 days) and heal more slowly 1
Monitoring and Follow-Up
- Assess daily for new lesion formation, progression of neurological symptoms, or worsening diplopia 1
- Monitor renal function closely during antiviral therapy, with dose adjustments needed for renal impairment 1
- If lesions fail to begin resolving within 7-10 days, suspect acyclovir resistance and obtain viral culture with susceptibility testing 1
- Watch for bacterial superinfection (extensive erythema, purulence, worsening pain) 2
Common Pitfalls to Avoid
- Do not rely on topical antiviral therapy—it is substantially less effective than systemic therapy and not recommended 1
- Do not discontinue treatment at exactly 7 days if lesions are still forming or have not completely scabbed 1
- Do not use short-course therapy designed for genital herpes (such as 5-day courses)—this is inadequate for VZV infection 1
- Avoid topical anesthetics as primary therapy—they provide minimal benefit for acute zoster pain 1
Prevention of Transmission
- Isolate the patient until all lesions have crusted over 2, 3
- Avoid contact with non-immunized pregnant women, immunocompromised individuals, and newborns 2
- Varicella zoster immunoglobulin should be administered within 96 hours to non-immunized contacts at risk 1, 2