This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Special Senses, Subject name: Physiology
A 60-year-old woman visits the ophthalmologist because of eye pain. Tests show that her right eye has an intraocular pressure of 22 mm Hg and her left eye has an intraocular pressure of 25 mm Hg. Which of the following is the most likely cause of eye pain in this woman? 
Select and explain. 
A. Decreased hydraulic resistance of trabecular meshwork, B. Decreased production of aqueous humor, C. Increased hydraulic resistance of trabecular meshwork, D. Increased production of aqueous humor
C: Increased hydraulic resistance of trabecular meshwork
Answer: C: Increased hydraulic resistance of trabecular meshwork 
Explanation: This woman has open-angle glaucoma, which is the most common type of glaucoma. Glaucoma is the second leading cause of blindness worldwide after cataracts. Blindness occurs because of damage to the optic nerve. The high intraocular pressure causes blood vessels and axons of the optic nerve to be compressed at the optic disc, which leads to poor nutrition with possible death of the neurons. The main cause of open-angle glaucoma is reduced flow of aqueous humor through the trabecular meshwork because of tissue debris, white blood cells, deposition of fibrous material, and other factors that increase the hydraulic resistance of the meshwork