Closed-angle glaucoma and open-angle glaucoma

Closed-angle glaucoma and open-angle glaucoma are two main types of glaucoma, both involving an increase in intraocular pressure, but they differ in their anatomy and presentation. 1. **Open-Angle Glaucoma**: This is the most common type of glaucoma, accounting for about 90% of all cases. The drainage angle formed by the cornea and iris remains open, but the trabecular meshwork, which functions as the eye's drainage route for the aqueous humor, becomes less efficient over time. This leads to an increase in intraocular pressure, which in turn can cause optic nerve damage. The progression of open-angle glaucoma is usually slow and symptoms may not be noticed until the disease is advanced. Visual field loss in open-angle glaucoma typically begins peripherally and then progresses to tunnel vision in the advanced stages. 2. **Closed-Angle Glaucoma**: This form of glaucoma, also known as acute or angle-closure glaucoma, occurs when the iris bulges forward to narrow or block the drainage angle formed by the cornea and the iris, preventing the eye fluid (aqueous humor) from flowing out of the eye. This can lead to a sudden increase in intraocular pressure. Symptoms can be severe and may include sudden eye pain, nausea, headache, and visual disturbances like halos around lights. This is a medical emergency and requires immediate intervention to prevent permanent vision loss. In terms of management, open-angle glaucoma is usually treated with pressure-lowering eye drops, laser trabeculoplasty, or surgery. Closed-angle glaucoma typically requires immediate treatment, which may involve medications to lower intraocular pressure, a laser procedure (iridotomy), or surgery. Regular eye exams are crucial for early detection of both types of glaucoma.

Author

Paddy Kalish OD, JD and B.Arch