A 32-year-old woman presents with a 5-day history of right eye pain, photophobia, and blurred vision. She reports a vesicular rash on the forehead and upper eyelid 3 days prior to ocular symptoms. On examination, visual acuity is 6/12, and slit-lamp biomicroscopy reveals multiple branching, dendritic ulcers with terminal bulbs on the cornea. Fluorescein staining is positive. What is the most appropriate next step in management?

Explanation

## Diagnosis **Key Point:** The clinical presentation of dendritic ulcers with terminal bulbs, positive fluorescein staining, and preceding vesicular rash on the forehead (V1 distribution) is pathognomonic for **Herpes Simplex Virus (HSV) keratitis**, specifically primary herpetic keratoconjunctivitis. ## Management Principles ### Systemic Antiviral Therapy **High-Yield:** Oral acyclovir 400 mg five times daily for 7–10 days is the gold standard for HSV keratitis. Systemic therapy: - Achieves therapeutic levels in the cornea and aqueous humour - Reduces viral shedding and recurrence risk - Prevents dissemination to the contralateral eye - More effective than topical agents alone ### Supportive Care **Clinical Pearl:** Topical lubricants (preservative-free artificial tears) are essential to prevent secondary bacterial infection and promote epithelial healing. Avoid topical anaesthetics for prolonged use (risk of neurotrophic keratopathy). ### What NOT to Do | Intervention | Reason for Avoidance | |---|---| | Topical corticosteroids monotherapy | Contraindicated — risk of **geographic ulcer** (expansion of epithelial defect) and stromal melting. Use only with concurrent systemic antivirals if stromal involvement present. | | Topical acyclovir alone | Insufficient corneal penetration; systemic therapy mandatory for epithelial HSV keratitis. | | Bandage contact lens without antivirals | Delays healing, increases infection risk, and allows unchecked viral replication. | ## Pathophysiology **Mnemonic: DENDRITIC = Herpes Simplex** - **D**endritic morphology (branching pattern) - **E**pithelial ulcer (superficial) - **N**ucleated cells (viral cytopathic effect) - **D**eep staining with fluorescein - **R**ecurrent (high recurrence rate ~25% per year) - **I**nfectious (viral shedding continues) - **T**erminal bulbs (pathognomonic) - **I**mmune-mediated (stromal disease in recurrent cases) - **C**orneal scarring (if untreated) [cite:Khurana Comprehensive Ophthalmology Ch 5]