The trabecular meshwork is a specialised structure located between the iris and the base of the cornea. It regulates eye pressure by draining a type of fluid produced inside the eye called the aqueous humour. This is different from tears which is produced outside of the eye.
The aqueous humour provides nourishment to cells inside the eye and also to keep the eye inflated. The pressure to keep the eye inflated is what eye doctors commonly refer to as the eye pressure. The production of aqueous humour is constantly matched by the drainage to the trabecular meshwork to maintain normal eye pressure.
If the trabecular meshwork is not working properly, the eye pressure will increase to harmful levels that might damage the optic nerve, causing visual loss. This condition is known as glaucoma. It affects our field of vision (peripheral vision) and patients do not tend to notice any symptoms early on in the disease. However, patients will start noticing their field of vision getting smaller as the disease progresses, eventually leading to tunnel vision. Glaucoma that are present from birth are know as primary congenital glaucoma.