What are the different types of glaucoma?

Glaucoma is typically divided into two major types according to the appearance of the drainage system within the eye: open-angle glaucoma (i.e., the angle where the iris meets the cornea is as wide and open as it should be) and angle-closure (also called closed-angle or narrow-angle) glaucoma (i.e., the angle where the iris meets the cornea is narrower than it should be). Within each type, the condition can be primary (i.e., with no identifiable cause) or secondary (i.e., caused by an existing condition).^[1] This means that different types of glaucoma can fall under one of the following four categories:^[2]

1. Primary open-angle glaucoma. Examples include primary open-angle high-tension glaucoma, primary open-angle normal-tension glaucoma, and juvenile glaucoma.
2. Secondary open-angle glaucoma. Examples include pseudoexfoliative glaucoma, pigmentary glaucoma, and uveitic glaucoma.
3. Primary angle-closure glaucoma. Examples include acute primary angle-closure glaucoma and chronic primary angle-closure glaucoma.
4. Secondary angle-closure glaucoma. Examples include neovascular glaucoma and miotic-induced malignant glaucoma.