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
The cause of decreased outflow of aqueous in a case of primary open angle glaucoma in diabetic: 
Select and explain. 
A. Block in episcleral veins, B. Lens lymphatic blockage, C. Block in trabecular meshwork, D. Infection of iris
C: Block in trabecular meshwork
Answer: C: Block in trabecular meshwork 
Explanation: Block in trabecular meshwork