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 age 5 years, presents with loss of vision and mild proptosis of left eye. On examination direct light reflex is absent but consensual is present in left eye. He is – \nSelect and explain. \nA. Optic nerve glioma, B. Optic sheath meningioma, C. Retinoblastoma, D. Optic disc angioma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Information in this question are :-\n\nAge 5 year\nLoss of vision and proptosis\nAbsent ispsilateral direct light reflex with present ipsilateral consensual reflex → Total afferent pupillary defect (amaurotic light reflex).\n\nAfferent pupillary defect can be seen in optic nerve glioma and optic nerve sheath angioma, amongst the given options. Both of these can cause loss of vision and proptosis. However optic nerve glioma occurs in first decade of life while optic nerve sheath mengioma occurs in adulthood. So, the best answer here is optic nerve glioma\nRetinoblastoma and optic disc angioma do not cause afferent pupillary defect.', 'role': 'assistant'}]