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: Unknown
[{'content': 'The sign of retrobulbar neuritis is - \nSelect and explain. \nA. Optic atrophy, B. Papilledema, C. Circumciliary congestion, D. Impairment of color vision', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans- D Optic Neuritis A. Papilitis Most common causes : Multiple sclerosis. Ophthalmoscopic features: Swollen optic disc up to 2 D Hyperemic disc. Disc margins blurred. Clinical feature Usually U/L Sudden loss of vision. Pain on eye movement (retrobulbar neuritis) Marcus gunn pupil or RAPD (Relative Afferent Pupillary Defect) Centrocaecal scotomas. Impairment of color vision Uthoff sign-worsening of vision with increase in body temperature Pulfrich phenomenon-Abnormal depth perception (oscillating object seems to move in elliptical direction) Treatment (ONTT TRIAL) 1ST three days i/v methyl prednisofone Followed by tapering dose of oral Prednisolone over 11 days. Total = 3+11=14 days Investigation of choice : MRI (orbits + Brain) T2W with contrast Retrobulbar neuritis(Involvement of retro laminar part of optic nerve). Ophthalmoscopic feature-Normal optic nerve head and retinal nerve fibre layer. S/S- Similar to papillitis. Neuroretinitis Disc edema and Macular star.', 'role': 'assistant'}]