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': 'A child presents with sudden loss of vision with painful ocular movements. The eye is white and there are no obvious signs on ophthalmoscopy. The most likely diagnosis is - \nSelect and explain. \nA. Optic nerve glioma, B. Retrobulbar neuritis, C. Craniopharyngioma, D. Papillitis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Information in this question are :-\n\n\nSudden loss of vision\nPainful ocular movement\nNormal fundus on ophthalmoscopy\n\n\nAll are seen in retrobulbar neuritis and last two features are more characteristics of retrobulbar neuritis and differentiate it from papillitis.\n\nPapillitis vs retrobulbar neuritis\n\nPapillitis and retrobulbar neuritis have almost same clinical features except :\n\ni) Painful ocular movement is more common in retrobulbar neuritis than papillis\nii)\xa0Fundus is normal in retrobulbar neuritis while papillitis has characteristic fundus abnormalities.', 'role': 'assistant'}]