What are the different types of glaucoma?

Primary Open-Angle Glaucoma. This is the most common form of glaucoma in the United States.

The risk of developing primary open-angle glaucoma increases with age. The drainage angle of the eye becomes less efficient over time, and pressure within the eye gradually increases, which can damage the optic nerve. In some patients, the optic nerve becomes sensitive even to normal eye pressure and is at risk for damage. Treatment is necessary to prevent further vision loss.

Typically, open-angle glaucoma has no symptoms in its early stages, and vision remains normal. As the optic nerve becomes more damaged, blank spots begin to appear in your field of vision. You typically won’t notice these blank spots in your day-to-day activities until the optic nerve is significantly damaged and these spots become large. If all the optic nerve fibers die, blindness results.

Closed-Angle Glaucoma. Some eyes are formed with the iris (the colored part of the eye) too close to the drainage angle. In these eyes, which are often small and farsighted, the iris can be pushed forward, blocking the drainage channel completely. Since the fluid cannot exit the eye, pressure inside the eye builds rapidly and causes an acute closed-angle attack.

Symptoms may include:

• Blurred vision
• Severe eye pain
• Headache
• Rainbow-colored halos around lights
• Nausea and vomiting

This is a true eye emergency. If you have any of these symptoms, call your ophthalmologist immediately. Unless this type of glaucoma is treated quickly, blindness can result.

Two-thirds of those with closed-angle glaucoma develop it slowly without any symptoms prior to an attack.