How many categories of glaucoma are there?

Glaucoma is commonly classified into several categories based on the mechanism of increased intraocular pressure (IOP) and other clinical features. The primary categories include:

1. Open-Angle Glaucoma: This is the most prevalent form of glaucoma where the angle between the iris and the cornea is normal, but the drainage system of the eye is not functioning effectively.

2. Angle-Closure Glaucoma: This occurs when the iris is too close to the drainage angle in the eye, blocking the outflow of fluid. It can happen suddenly (acute) or gradually (chronic).

3. Normal-Tension Glaucoma: In this condition, optic nerve damage occurs despite normal IOP levels, indicating that other factors contribute to nerve damage.

4. Secondary Glaucoma: This category includes any form of glaucoma resulting from other medical conditions, eye injuries, or medications that affect intraocular pressure.

These classifications help in diagnosing and determining the appropriate treatment for the specific type of glaucoma. Understanding these categories is crucial for medical coding purposes, as they will dictate how conditions are classified and billed in healthcare settings.