This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inflammations of the Cornea, Subject name: Ophthalmology
'Ischemic necrosis' in alkali burn is - 
Select and explain. 
A. Stage I, B. Stage II, C. Stage III, D. Stage IV
A: Stage I
Answer: A: Stage I 
Explanation: Ans. is 'a' i.e., Stage I o Alkali bums are among the most severe chemical injuries to eye.o Common alkalies responsible for bums are liquid ammonia (most harmful), lime, caustic potash or caustic soda,o Clinical features are divided into three stages.Acute ischemic necrosis (Stage I) In this stage there are signs in conjunctiva (edema, congestion, necrosis, copious discharge), cornea (sloughing, edema and opacity) and iris (iridocyclitis),Reparation (Stage II)Conjunctival and comeal epithelium regenerate, and there is comeal neovascularization. Complications (Stage III) Symblepharon, recurrent corneal ulceration, complicated cataract, secondary glaucoma.