What are the two primary categories of glaucoma?

• A. Primary open-angle glaucoma and closed-angle glaucoma
• B. Primary angle-closure glaucoma and secondary glaucoma
• C. Secondary open-angle glaucoma and primary open-angle glaucoma
• D. Normal tension glaucoma and pigmentary glaucoma

Answer: (A)

The main idea is classification by how the eye’s drainage angle affects outflow. When the angle is open but drainage through the trabecular meshwork is slow, it’s primary open-angle glaucoma, a chronic and usually painless rise in intraocular pressure. When the angle is closed or blocked, outflow is abruptly restricted, leading to primary angle-closure glaucoma, which can present as an acute emergency with eye pain, redness, and vision changes.

This distinction matters because it shapes treatment and urgency: open-angle glaucoma is typically managed long-term with medications, laser therapy, or surgery to lower pressure, while angle-closure glaucoma often requires rapid pressure reduction and urgent intervention to prevent vision loss. There are other forms, like secondary glaucomas or normal tension glaucoma, but the two broad primary categories are open-angle and angle-closure glaucoma.