What is open angle glaucoma?

In most cases, glaucoma is caused by increased pressure in the eye. In a healthy eye, a balance exists between the fluid produced, and the fluid that leaves the eye. Primary open angle glaucoma occurs when the drainage channels are open, but do not drain fluid properly. In order to maintain a healthy balance, the eye has a built-in drainage system. Primary open angle glaucoma occurs due to a deeper issue, that impacts the eyes natural drainage system. The eye's drainage system works like a sink. If a blockage develops, or if fluid is produced faster than it can escape, an overflow will occur. In the eye, this overflow causes the pressure to elevate. The optic nerve is the structure most vulnerable to damage from elevated pressure. Continuous elevated pressure or spikes in pressure, can damage the optic nerve. If left untreated, glaucoma can lead to blindness, which is irreversible.