Ulcer serpens caused by:

Ans: a (Pneumococcus) Ref: AK khurana, 4th ed, p. 96Ulcer serpens:Hypopyon comeal ulcer by pneumococcusCreeping ulcer over cornea in serpeginous fashionUsually associated with violent iridocyclitisFormed due to iritis due to bacterial toxins causing outpouring of PMN cells; hence sterile( no invasion of bacteria)Organisms that can freely invade cornea:Corynebacterium diphtheriaNeisseria gonnorheaNeisseria meningitidesCharacteristics of fungal comeal ulcer1. Dry looking ulcer with elevated rolled out margins2. Multiple satellite lesions around the ulcer3. Delicate feathery fingerlike extensions4. Sterile immune ring5. Big hypopyon which may not be sterile