A 52-year-old farmer from rural Maharashtra presents with a 5-day history of right eye pain, photophobia, and purulent discharge. He reports a history of trauma with a vegetative matter (sugarcane leaf) 1 week ago. On examination, visual acuity is 6/60. Slit-lamp examination reveals a 4 mm central corneal ulcer with raised, irregular borders, satellite lesions, and a hypopyon. KOH mount of corneal scrapings shows branching septate hyphae. What is the most appropriate initial management?

Explanation

## Clinical Diagnosis **Key Point:** The clinical presentation—vegetative trauma, raised irregular borders, satellite lesions, hypopyon, and KOH-positive branching septate hyphae—is pathognomonic for **fungal corneal ulcer**, most likely *Aspergillus* or *Fusarium*. ## Antifungal Choice | Feature | Natamycin | Voriconazole | Itraconazole (oral) | |---------|-----------|--------------|---------------------| | **Spectrum** | Broad (Aspergillus, Fusarium, Candida) | Broad but variable corneal penetration | Systemic adjunct; poor corneal penetration | | **Corneal penetration** | Excellent (polyene; does not cross BBB) | Moderate; better for molds than natamycin | Poor; requires systemic dosing | | **Formulation** | Topical suspension 5% | Topical 1% solution | Oral only | | **DOC for fungal keratitis** | **YES** (gold standard) | Second-line if natamycin unavailable | Adjunctive systemic therapy | **High-Yield:** Natamycin 5% is the **first-line topical agent** for fungal keratitis because it achieves high corneal concentrations and covers *Aspergillus*, *Fusarium*, and *Candida*. Hourly application (initially 6–8 times daily) is essential. ## Systemic Adjunct **Clinical Pearl:** Oral itraconazole 400 mg daily (in divided doses) is added to natamycin for: - Deep stromal or descemetocele involvement - Immunocompromised patients - Severe or progressive ulcers Oral therapy alone is **insufficient** because corneal penetration is poor. ## Why This Case Requires Both 1. **Hypopyon** and **satellite lesions** suggest deep stromal involvement and aggressive infection. 2. **Vegetative trauma** (high fungal inoculum) warrants aggressive dual therapy. 3. Natamycin topical + itraconazole systemic is the **standard of care** for moderate-to-severe fungal keratitis [cite:Khurana Textbook of Ophthalmology Ch 4]. **Mnemonic:** **NAT-ITRA** = **NAT**amycin (topical) + **ITRA**conazole (systemic) for fungal keratitis.