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
[{'content': 'Earliest Ocular sign in acoustic neuroma is: \nSelect and explain. \nA. Diplopia, B. Ptosis, C. Loss of corneal sensation, D. Congestion of conjunctiva', 'role': 'user'}, {'content': 'Answer: C \nExplanation: 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"', 'role': 'assistant'}]