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: Ophthalmology
Earliest Ocular sign in acoustic neuroma is: 
Select and explain. 
A. Diplopia, B. Ptosis, C. Loss of corneal sensation, D. Congestion of conjunctiva
C: Loss of corneal sensation
Answer: C: Loss of corneal sensation 
Explanation: Loss of corneal sensation REF: Harrison's 17th ed chapter 374 "The earliest ocular manifestation of CP angle tumors or acoustic neuroma is loss of corneal sensation"