A 30-year-old patient presents with recurrent episodes of painful red eye, blurred vision, and tearing. Slit-lamp examination reveals a geographic, map-shaped epithelial defect with dendritic borders that stains with rose Bengal at its edges but not with fluorescein at the centre. This morphology is characteristic of:
- A Herpes simplex stromal keratitis (disciform keratitis)
- B Acanthamoeba keratitis — pseudodendrites
- C Herpes simplex epithelial keratitis — geographic ulcer (advanced dendritic) ✓
- D Neurotrophic keratopathy — chronic epithelial defect
Explanation
A geographic (amoeboid or map-shaped) corneal ulcer with scalloped, dendritic-type edges is the advanced stage of herpes simplex epithelial keratitis, where the classic dendritic ulcer enlarges. The edges of the ulcer contain active virus (staining with rose Bengal) while the central base stains with fluorescein. Treatment is topical antiviral (acyclovir or ganciclovir) or systemic acyclovir. Disciform keratitis is a stromal immune reaction with disc-shaped oedema, Descemet's folds, and keratic precipitates without epithelial defect. Acanthamoeba produces pseudodendrites that are raised, have less defined branching, and lack the scalloped geographic pattern. Neurotrophic keratopathy shows a smooth-edged oval or round epithelial defect, not geographic branching.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.