Types of glaucoma at a glance
There is not just “one” glaucoma but several forms. The four most important:
Open-angle glaucoma (most common)
the drainage angle is open, but the fine drainage system works poorly. Pressure rises slowly and painlessly over years.
Normal-tension glaucoma
a subtype of open-angle glaucoma. The optic nerve is damaged even though the measured pressure is in the “normal” range. Here the nerve is especially pressure-sensitive; blood flow and blood pressure may also play a role.
Narrow-angle or angle-closure glaucoma
the drainage angle is narrow or blocked. This can develop slowly or occur suddenly as a painful emergency (see the page “Emergency: acute angle closure”).
Secondary glaucoma
a result of another cause, e.g. inflammation, injury, certain medicines (cortisone) or other eye diseases.
Rarer are congenital / childhood glaucomas. Your ophthalmologist determines which form you have; treatment depends on it.