Commonest cause of posterior staphyloma is:

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.