This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
An indication for therapeutic keratoplasty is: 
Select and explain. 
A. Progressive corneal ulcer, B. Keratoconus, C. Anterior staphyloma, D. High myopia
B: Keratoconus
Answer: B: Keratoconus 
Explanation: In keratoplasty the diseased corneal disc is replaced by a corresponding sized graft from a human cadaver eye. Penetrating (full thickness) keratoplasty Lamellar (paial thickness) keratoplasty Keratoconus Interstitial keratins Salzmann's nodular dystrophy Mycotic corneal ulcer Corneal abscess Corneal dystrophy Disciform keratitis Recurrent pterygia Complications of keratoplasty Anterior synechia Vascularization Secondary glaucoma Rejection of graft A corneal graft which be obtained within 4 hours of death carries good prognosis.