This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cornea, Subject name: Ophthalmology
Percentage of endothelial loss in Descemets stripping automated endothelial keratoplasty 
Select and explain. 
A. 5%, B. 10 - 20%, C. 30 - 40%, D. 50 - 60%
C: 30 - 40%
Answer: C: 30 - 40% 
Explanation: Ans. (c) 30 - 40%Ref: Cornea: July 2007- Volume 26 - Issue 6 p. 670 - 674)Reported mean endothelial cell loss (usually at 6 months post op) varies from 24-59% (with standard deviations) across the studies.