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Zoster Ophthalmic Involvement (Herpes Zoster Ophthalmicus)

What is Zoster Ophthalmic Involvement?

Zoster ophthalmic involvement, also called herpes zoster ophthalmicus (HZO), occurs when the varicella‑zoster virus (VZV) reactivates in the ophthalmic (V1) branch of the trigeminal nerve. This branch supplies the forehead, scalp, upper eyelid, conjunctiva, cornea, and portions of the nose. When VZV spreads along these sensory fibers, it can cause a painful rash and inflammation of ocular structures, ranging from mild conjunctivitis to sight‑threatening keratitis, uveitis, or retinal necrosis.

The condition is a medical emergency because permanent vision loss can develop within days if treatment is delayed. Early recognition and antiviral therapy dramatically improve outcomes.<sup>1</sup>

Common Causes

While the direct cause is reactivation of latent VZV, several factors increase the risk of ophthalmic involvement:

• Age ≥ 50 years – immune surveillance declines with age.
• Immunosuppression – HIV/AIDS, organ transplantation, chemotherapy, or chronic steroid use.
• Previous chicken‑pox infection – the virus remains dormant in dorsal root and cranial nerve ganglia.
• Stress or trauma – physical or emotional stress can trigger reactivation.
• Systemic diseases – diabetes mellitus, malignancy, or autoimmune disorders.
• Vaccination status – lack of shingles vaccine (Shingrix) in eligible adults.
• Neurological conditions – prior trigeminal neuralgia or facial nerve palsy.
• Radiation therapy to the head/neck – damages local immunity.
• Chronic ocular surface disease – dry eye or blepharitis may predispose to secondary infection.
• Medication-induced immunomodulation – biologics (e.g., TNF‑α inhibitors) used for rheumatoid arthritis or psoriasis.

Associated Symptoms

Patients with HZO often experience a combination of skin, nerve, and eye findings:

• Prodromal pain – burning, throbbing, or stabbing pain in the forehead or upper eyelid preceding any rash.
• Vesicular rash – clusters of fluid‑filled blisters following the V1 dermatome (forehead, scalp, tip of the nose – “Hutchinson’s sign”).
• Conjunctival injection – redness of the white of the eye.
• Keratitis – pain, photophobia, tearing, and decreased visual acuity due to corneal involvement.
• Uveitis – eye redness, floaters, and blurred vision from inflammation of the iris and ciliary body.
• Eyelid edema or ptosis.
• Dry eye or excessive tearing – due to impaired lacrimal gland function.
• Headache – often localized to the same side as the rash.
• Neuropathic itch or dysesthesia – lingering after the rash resolves (post‑herpetic neuralgia).

When to See a Doctor

Seek medical attention promptly if you notice any of the following:

• Unilateral facial pain or burning before a rash appears.
• A rash on the forehead, scalp, or tip of the nose, especially if it involves the eye.
• Redness, swelling, or pain in the eye accompanied by sensitivity to light.
• Sudden change in vision—blurred, double, or loss of vision in one eye.
• Persistent fever or feeling unwell along with the rash.
• Any sign of eye discharge that is thick, yellow, or green.

Because antiviral therapy is most effective when started within 72 hours of rash onset, do not wait for symptoms to worsen.

Diagnosis

Evaluation of HZO involves both clinical examination and targeted investigations:

1. Detailed History

• Onset and progression of pain, rash, and visual changes.
• Immune status, vaccination history, and recent illnesses.

2. Physical Examination

• Inspection of the skin for vesicular lesions in the V1 distribution (including “Hutchinson’s sign”).
• Comprehensive ocular exam – visual acuity, pupillary reactions, slit‑lamp biomicroscopy to assess cornea, conjunctiva, iris, and anterior chamber.
• Fundoscopic exam for retinal involvement (e.g., acute retinal necrosis).

3. Laboratory Tests

• Polymerase chain reaction (PCR) of vesicular fluid or conjunctival swab – highly specific for VZV.
• Serology for VZV IgM/IgG (useful if PCR unavailable).

4. Imaging (when indicated)

• Ocular ultrasound or OCT (optical coherence tomography) – evaluates corneal thickness, edema, or retinal lesions.
• MRI of the brain/orbits – reserved for suspected orbital cellulitis, optic neuritis, or central nervous system spread.

Diagnosis is primarily clinical; laboratory confirmation is helpful for atypical cases or immunocompromised patients.

Treatment Options

Management focuses on rapid antiviral therapy, control of inflammation, and protection of the ocular surface.

1. Antiviral Medications (First‑line)

• Acyclovir 800 mg orally five times daily for 7–10 days.
• Valacyclovir 1 g orally three times daily (more convenient dosing).
• Famciclovir 500 mg orally three times daily.
• Intravenous acyclovir (10 mg/kg every 8 h) is recommended for severe ocular disease, immunocompromised patients, or those unable to tolerate oral meds.

Therapy should begin within 72 hours of rash onset; however, treatment beyond this window still benefits patients with active ocular inflammation.<sup>2</sup>

2. Corticosteroids

• Topical prednisolone eye drops (e.g., 1 % prednisolone acetate) to reduce stromal keratitis or anterior uveitis.
• Oral prednisone (0.5 mg/kg) may be added in severe inflammation, tapering over 2–3 weeks.
• Use only under ophthalmologist supervision because steroids can worsen viral replication if given alone.

3. Pain Management

• Acetaminophen or NSAIDs for mild to moderate pain.
• Neuropathic agents (gabapentin, pregabalin, or tricyclic antidepressants) for post‑herpetic neuralgia.
• Topical lidocaine ointment for surface pain (short‑term use).

4. Ocular Surface Support

• Preservative‑free artificial tears every 2–4 hours.
• Therapeutic contact lenses (bandage lenses) if there is epithelial defect.
• Topical antibiotics (e.g., moxifloxacin) if secondary bacterial infection is suspected.

5. Surgical Intervention

• Penetrating keratoplasty for progressive corneal scarring causing vision loss.
• Vitrectomy for retinal detachment or necrosis.

6. Follow‑up Care

Patients require close ophthalmologic follow‑up—initially within 24–48 hours, then weekly until the inflammation resolves, and subsequently as needed for visual rehabilitation.

Prevention Tips

• Shingles vaccination – Recombinant zoster vaccine (Shingrix) is >90 % effective in preventing HZO and is recommended for adults ≥50 years and for immunocompromised individuals ≥18 years.
• Maintain a healthy immune system: balanced diet, regular exercise, adequate sleep, and stress management.
• Control chronic diseases (diabetes, hypertension) to reduce immune compromise.
• Avoid close contact with individuals who have active chicken‑pox or shingles lesions if you are immunosuppressed.
• Promptly treat any primary varicella infection in children; it reduces later viral load.
• If you have a history of shingles, discuss prophylactic antiviral therapy with your doctor during periods of intense immunosuppression.

Emergency Warning Signs

Key Take‑aways

• Herpes zoster ophthalmicus is a reactivation of VZV in the V1 trigeminal branch and can threaten vision.
• Early antiviral therapy (within 72 hours) and ophthalmology‑guided anti‑inflammatory treatment are essential.
• Vaccination with Shingrix is the most effective preventive measure for adults.
• Do not wait for symptoms to worsen—any ocular involvement warrants urgent evaluation.

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