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
Most common etiolopathogenetic cause of glaucoma is: March 2012 
Select and explain. 
A. Raised pressure in episcleritic veins, B. Decreased outflow, C. Increased formation of aqueous humour, D. Increased scleral outflow
B: Decreased outflow
Answer: B: Decreased outflow 
Explanation: Ans: B i.e. Decreased outflow A sustained increase in intraocular pressure may be due to increased formation of the aqueous humour, difficulty in its exit, or a raised pressure in the episcleral veins of these, the first & last rarely occur, and it follows that raised intraocular pressure is essentially due to an increased resistance to the circulation of the aqueous at the pupil and/ or its drainage through the angle of the anterior chamber.