A 33 years old male came with pain and watering in the right eye for 36 hours. On examination, a 3 x 2 cm corneal ulcer is seen with elevated margins, feathery hyphae, finger like projections and minimal hypopyon in cornea. What is the likely causative organism?
Aspergillosis
Pseudomonas
Acanthamoeba
HSV-1
Ans: A. AspergillosisRef: Yanoff & Duker 4/e p225; Parson 22/e p203, 21/e p199)Finding suggestive of fungal corneal ulcer. In the question, Aspergillus is the only fungus.Mycotic or fungal keratitis:Commonly due to Aspergillus, Fusarium or Candida albicans.Fungal ulcers are typically seen after injury with vegetable matter such as a thorn or wooden stick and are characterized by a relatively indolent course.Symptoms are much milder than the clinical signs would suggest.Dry slough with feathery borders, surrounded by a yellow line of demarcation, which gradually deepens into a gutter.An immune ring (Wessely) may be visible due to deposition of immune complexes and inflammatory cells around the ulcer.Marked ciliary and conjunctival congestion.Hypopyon is thick and immobile - Due to direct invasion into the anterior chamber of fungal hyphae enmeshed in thick exudates.