Most common cause of posterior staphyloma -
Ans. is 'c' i.e.. Myopia [Ref: Parson 21st/ep. 223)Staphylomao Staphyloma is an abnormal protrusion of uveal tissue through a weak and thin portion of cornea or sclera,o So, a staphyloma is lined internally by uveal tissue and externally by weak cornea or sclera.o Staphyloma is divided anatomically into : -Anterior staphyloma : - Protrusion and adhesion of iris 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.Intercalary' staphyloma : - It occurs at the limbus. It is lined 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 scleritis, Scleromalacia perforans, Complicated cataract surgery, secondary angle closure glaucoma.Ciliary staphyloma : - This affects the ciliary zone that includes 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.Equatorial staphyloma : - This occurs at the equatorial region of the eye with incarceration of the choroid. Causes are scleritis, degenerative myopia and chronic uncontrolled glaucoma.Posterior staphyloma : - Occurs at posterior pole and is lined internally by choroid. Degenerative high axial myopia is the most common cause.
Trauma
Glaucoma
Myopia
Scleritis
Sclera