This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sclera, Subject name: Ophthalmology
[{'content': 'Commonest cause of posterior staphyloma is: \nSelect and explain. \nA. Glaucoma, B. Retinal detachment, C. iridocyclitis, D. High myopia', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. d (High myopia). (Ref: Ophthalmology by AK Khurana 2nd ed. 151)POSTERIOR STAPHYLOMA# It refers to bulge of weak sclera lined by the choroid behind the equator.# Common causes are:- Pathological myopia,- Posterior scleritis and- Perforating injuries.# Diagnosed best on ophthalmoscopy# It is seen as an excavated area with retinal vessels dipping in it.Excessively progressive degenerative myopia leads to sclerectasia circumscribed behind or posterior staphyloma. This is a sharply demarcated bulging of the entire posterior pole, which is associated with massive chorioretinal atrophy.', 'role': 'assistant'}]