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Zona (Herpes Zoster Ophthalmicus)

What is Zona (herpes zoster ophthalmicus)?

Zona, more commonly called herpes zoster ophthalmicus (HZO), is a reactivation of the varicella‑zoster virus (VZV) that involves the ophthalmic branch (V1) of the trigeminal (cranial nerve V) nerve. After a person recovers from chicken‑pox, VZV remains dormant in sensory ganglia. When the immune system is weakened—by age, disease, or medication—the virus can reactivate, travel along the V1 nerve, and cause a painful, vesicular rash on the forehead, scalp, and eye. The involvement of ocular structures can lead to complications ranging from mild conjunctivitis to sight‑threatening keratitis, uveitis, or optic neuritis.

HZO accounts for about 10‑15 % of all shingles cases, and its incidence rises sharply after age 50. Prompt recognition and treatment are crucial because eye damage can become permanent.

Common Causes

While the underlying trigger is the same—reactivation of latent VZV—several conditions increase the risk of developing HZO:

• Advanced age (especially > 50 years) – immune senescence reduces viral control.
• Immunosuppression – HIV/AIDS, organ transplantation, chemotherapy, or biologic agents.
• Chronic diseases – diabetes mellitus, chronic kidney disease, and chronic lung disease.
• Use of systemic steroids or other immunomodulatory drugs.
• Physical or emotional stress – can transiently lower immunity.
• Recent radiation therapy to the head or neck.
• Previous shingles episode – especially if it involved the V1 dermatome.
• Autoimmune disorders – e.g., systemic lupus erythematosus or rheumatoid arthritis.
• Malignancies – especially hematologic cancers like lymphoma.
• Vaccination status – lack of prior varicella‑zoster vaccination increases risk.

Associated Symptoms

In addition to the classic painful rash, patients with HZO often experience:

• Prodromal pain – burning, tingling, or itching in the forehead or eye that may precede the rash by 1–5 days.
• Conjunctival injection – redness of the eye.
• Photophobia – sensitivity to light.
• Decreased visual acuity – blurred vision or “shadow” over part of the visual field.
• Eye discharge – watery or mucoid.
• Corneal ulceration – painful erosions on the cornea.
• Uveitis – inflammation of the iris and ciliary body causing pain and light sensitivity.
• Hutchinson’s sign – vesicles on the tip of the nose, indicating involvement of the nasociliary branch and higher risk of ocular disease.
• Facial weakness – occasional involvement of the facial nerve (rare).
• Post‑herpetic neuralgia – persistent nerve pain lasting months after the rash resolves.

When to See a Doctor

Because ocular involvement can rapidly threaten vision, you should seek medical care promptly if you notice any of the following:

• Severe or worsening eye pain, especially if it does not improve with over‑the‑counter pain relievers.
• Redness, swelling, or discharge from the eye.
• Blurry or double vision.
• Presence of vesicles on the forehead, scalp, or tip of the nose (Hutchinson’s sign).
• Sensitivity to light that interferes with daily activities.
• Fever ≥ 38 °C (100.4 °F) accompanied by the rash.
• Any sign of a secondary bacterial infection (increasing pus, foul odor, rapidly spreading redness).

Even if the rash appears mild, involvement of the eye warrants urgent evaluation by an ophthalmologist or a health‑care provider experienced in ocular disease.

Diagnosis

Diagnosing HZO involves a combination of history, physical examination, and occasionally laboratory testing:

Clinical examination

• History taking – onset of pain, rash distribution, prior shingles, immunization status.
• Skin inspection – grouped vesicles on an erythematous base confined to V1 distribution; note Hutchinson’s sign.
• Slit‑lamp ophthalmic exam – evaluates cornea, conjunctiva, anterior chamber, and iris for keratitis, uveitis, or epithelial defects.
• Visual acuity testing – baseline measurement to monitor progression.

Laboratory tests (when needed)

• Polymerase chain reaction (PCR) of vesicular fluid – highly sensitive for VZV DNA.
• Direct fluorescent antibody (DFA) testing – rapid but less widely available.
• Serology – usually not required, as most adults are VZV‑IgG positive.

Imaging

• Anterior segment optical coherence tomography (AS‑OCT) – assesses corneal thickness and edema.
• Fundus photography or fluorescein angiography – if posterior segment involvement is suspected.

Treatment Options

Early antiviral therapy dramatically reduces the risk of ocular complications and post‑herpetic neuralgia. Treatment is a combination of systemic medication, topical eye drops, and supportive care.

Systemic antiviral therapy

• Acyclovir 800 mg five times daily for 7–10 days.
• Valacyclovir 1 g three times daily (more convenient dosing).
• Famciclovir 500 mg three times daily.

Guidelines from the CDC and American Academy of Ophthalmology recommend beginning antiviral treatment within 72 hours of rash onset, but therapy should still be started later if ocular disease is present.

Adjunctive corticosteroids

Topical steroids (e.g., prednisolone acetate 1 %) are often prescribed by ophthalmologists to control intra‑ocular inflammation, but they must be used under close supervision because they can increase the risk of secondary infection.

Topical antiviral eye drops

• Trifluridine 1 % ophthalmic solution – applied 5–6 times daily for 7 days.
• Penciclovir 1 % ointment – may be used for epithelial keratitis.

Pain management

• Acetaminophen or ibuprofen for mild‑moderate pain.
• Neuropathic pain agents (gabapentin, pregabalin, or duloxetine) if pain persists beyond the rash.
• Short‑course oral steroids may be considered for severe orbital or ocular inflammation, but only after antiviral therapy is underway.

Supportive home care

• Keep lesions clean and dry; avoid scratching.
• Apply cool compresses to reduce discomfort.
• Use artificial tears (preservative‑free) several times daily to relieve dryness.
• Wear sunglasses to minimize photophobia.
• Maintain good hand hygiene to prevent secondary bacterial infection.

Prevention Tips

Because HZO results from reactivation of a virus you already carry, the most effective preventive measures focus on strengthening immunity and vaccination:

• Shingles vaccine – The recombinant zoster vaccine (Shingrix) is > 90 % effective at preventing shingles and its complications, including HZO, for adults ≥ 50 years. The CDC recommends two doses administered 2–6 months apart.
• Maintain a healthy immune system – balanced diet, regular exercise, adequate sleep, and stress reduction.
• Control chronic diseases – keep diabetes, hypertension, and COPD well‑managed.
• Avoid unnecessary immunosuppression – discuss risks with your physician when starting steroids or biologics.
• Prompt treatment of initial shingles – early antiviral therapy reduces the risk of V1 involvement.
• Good eye hygiene – wash hands before touching eyes, especially during an active rash.

Emergency Warning Signs

Key Take‑aways

Herpes zoster ophthalmicus is a medical emergency for the eye. Early recognition, prompt antiviral therapy, and close follow‑up with an ophthalmologist are essential to preserve vision and reduce long‑term pain. Vaccination with Shingrix remains the most effective preventive strategy, especially for adults over 50 or those with weakened immune systems.

References: CDC. “Shingles (Herpes Zoster) – Prevention.” 2024; Mayo Clinic. “Herpes Zoster (Shingles) – Symptoms & Causes.” 2023; American Academy of Ophthalmology. “Herpes Zoster Ophthalmicus.” 2024; NIH. “Varicella-Zoster Virus.” 2022; WHO. “Varicella and Herpes Zoster Vaccines.” 2023.

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