The term “open-angle” refers to the “drainage angle” at the front of the eye between the outer edge of the iris and sclera.
The highest risk factor for someone to develop glaucoma is raised pressure in the eye. Normally, there is a balance between the amount of fluid produced inside the eye and that draining from the eye into the bloodstream. The fluid passes through a mesh formed of cells and connective tissue. In glaucoma, this mesh, called the ‘trabecular meshwork’ gets partially blocked and the fluid can’t drain away properly, which results in a build-up of pressure. The reason why the trabecular meshwork becomes blocked isn’t always clear.
The increased pressure in the eye can damage the optic nerve at the back of the eye. The optic nerve is the communicating cable between the eye and the brain, so any damage to it causes visual impairment. Glaucoma usually affects both eyes. However, it can often progress more quickly in one eye than in the other.