Acanthamoeba keratitis is characterised on confocal microscopy by which finding?
- A Bright, round, double-walled cysts within the corneal stroma ✓
- B Fungal hyphae with 45° branching
- C Dendritic cells with long cytoplasmic projections
- D Amorphous hyaline deposits at Bowman layer
Correct answer: A. Bright, round, double-walled cysts within the corneal stroma
Explanation
Confocal microscopy in Acanthamoeba keratitis shows highly reflective, round double-walled cysts (10–25 µm diameter) within the corneal stroma; trophozoites may also be seen. This is the most sensitive non-invasive diagnostic method and can be used to monitor treatment response. Fungal hyphae appear as filamentous structures with variable reflectivity. Dendritic cells are normal resident corneal cells visible on confocal microscopy. Acanthamoeba cysts are a pathognomonic finding when identified in the clinical context.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.