What Is Glaucoma?

Glaucoma is a disease of the optic nerve-the part of the eye that carries the images we see to the brain. When damage to the optic nerve fibers occurs, blind spots develop. These blind spots usually go undetected until the optic nerve is significantly damaged. If the entire nerve is destroyed, blindness results. Early detection and treatment are the keys to preventing optic nerve damage and blindness from glaucoma.

What Causes Glaucoma?

Clear liquid called aqueous humor circulates inside the front portion of the eye. To maintain a healthy level of pressure within the eye, a small amount of this fluid is produced constantly while an equal amount flows out of the eye through a microscopic drainage system. (This liquid is not part of the tears on the outer surface of the eye).

Because the eye is a closed structure, if the drainage area is blocked, the excess fluid cannot flow out of the eye. Fluid pressure within the eye increases, pushing against the optic nerve and causing damage.

Open-angle glaucoma is the most common form. The drainage becomes less efficient over time, and pressure gradually increases, which can damage the optic nerve. Treatment is necessary to prevent further vision loss. Closed-angle glaucoma is a true eye emergency. Symptoms include:

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

If you have any of these symptoms, call your ophthalmologist immediately. Unfortunately, two-thirds of those with closed-angle glaucoma develop it slowly without any symptoms prior to attack.

How Is Glaucoma Treated?

Glaucoma is usually controlled with eye drops taken daily. These medications lower eye pressure, either by decreasing the amount of aqueous fluid produced within the eye or improving the flow through the drainage angle.

Laser surgery treatments may also be recommended. Selective Laser Trabeculoplasty (SLT) is a laser procedure that works by using light to stimulate the body's own healing response to lower eye pressure, thus reducing your dependency on eye drops.

When surgery in the operating room is needed to treat glaucoma, fine microsurgical instruments are used to create a new drainage channel for the aqueous fluid to leave the eye. As with laser surgery, surgery in the operating room is typically an outpatient procedure.