This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ocular trauma , Subject name: Ophthalmology
[{'content': "Berlin's edema is due to \nSelect and explain. \nA. Blunt trauma to eye, B. Extradural hemorrhage, C. Choroidal melanoma, D. Parsplanitis", 'role': 'user'}, {'content': "Answer: A \nExplanation: (Refer: AK Khurana Comprehensive Ophthalmology, 6th edition, pg no. 431)Berlin's edema (commotio retinae) is a common condition caused by blunt injury to the eye. It is characterized by a decreased vision in the injured eye a few hours after the injury. Under examination, the retina appears opaque and white in color in the periphery but the blood vessels are normally seen. Cherry-red' spot in the foveal region may be seen", 'role': 'assistant'}]