Primary open-angle glaucoma is a hereditary disease which alters the evacuation of aqueous humor, in the trabecular area. This alteration causes an increase in the intraocular pressure at pathological rates, which after some time causes anatomical damage to the optic nerve and functional damage to the visual field: characteristic of glaucoma. I refer to the reader to read Chap. 2 where you will find many definitions of primary open-angle glaucoma.