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': 'Posterior staphyloma, most common cause – \nSelect and explain. \nA. Trauma, B. Myopia, C. Iridocyclitis, D. Glaucoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Staphyloma\nStaphyloma is an abnormal protrusion of uveal tissue through a weak and thin portion of cornea or sclera\n\xa0\nSo, a staphyloma is lined internally by uveal tissue and externally by weak cornea or sclera.\no Staphyloma is divided anatomically into : -\n\xa0\nAnterior staphyloma: - Protrusion and adhesion ofiris to ectatic cornea. The most common cause is a sloughing corneal ulcer which perforates and heals with the formation of pseudocornea by the organization of exudates and laying down of fibrous tissue. It is lined internally by iris.\n\xa0\nIntercalary staphyloma: - It occurs at the limbus. It islined internally by the root of iris and the anterior most portion of the ciliary body. The causes are perforating injuries to limbus, marginal corneal ulcer, anterior scterilis, Scleromalacia perforans, Complicated cataract surgery, secondary angle closure glaucoma.\n\xa0\nCiliary staphyloma : This affects the ciliary zone thatincludes the region upto 8 mm behind the limbus. The ciliary body is incarcerated in the region of scleral ectasia. Causes arc Developmental glaucoma. Primary or secondary glaucoma end stage, scleritis, trauma to ciliary region.\n\xa0\nEquatorial staphyloma : - This occurs at theequatorial region of the eye with incarceration of the choroid.\n\xa0\nCauses are scleritis, degenerative myopia and chronic uncontrolled glaucoma.\nPosterior staphyloma : - Occurs at posterior pole andis lined internally by choroid. Degenerative high axial myopia is the most common cause.', 'role': 'assistant'}]