What is Glaucoma?

Glaucoma - Optic Nerve
The optic nerve

Glaucoma is a group of diseases that cause gradual vision loss that can lead to blindness. At first there may be no symptoms of the disease, and experts estimate over half of individuals affected by glaucoma may not even know that they have the disease.

Cut telephone wire
The optic nerve is like a cable cord

Glaucoma causes damage to the optic nerve. The optic nerve is like a cable cord that connects the eye to the brain. It is the information highway that relays the message of sight to your brain.

Glaucoma causes the intraocular pressure to rise inside of the eye. Treatment can prevent vision loss.

Types of Glaucoma

Narrow Angle Glaucoma

This type of glaucoma is also known as acute glaucoma or narrow angle glaucoma. It is much more rare and is very different from open angle glaucoma in that the eye pressure usually rises very quickly.

Glaucoma Fluid Outflow
Diagram of fluid outflow in glaucoma

This happens when the drainage canals get blocked or covered over, like a sink with something covering the drain.

With angle closure glaucoma, the iris is not as wide and open as it should be. The outer edge of the iris bunches up over the drainage canals, when the pupil enlarges too much or too quickly. This can happen when entering a dark room.

A simple test can be used to see if your angle is normal and wide or abnormal and narrow. Treatment of angle closure glaucoma usually involves laser surgery to remove a small portion of the outer edge of the iris. This helps unblock the drainage canals so that the extra fluid can drain. Usually surgery is successful and long lasting. However, you should still receive regular check-ups.

Symptoms of angle closure glaucoma may include headaches, eye pain, nausea, rainbows around lights at night, and very blurred vision.

Open Angle Glaucoma

Glaucoma Vision
Normal vision and Glaucoma vision

This is the most common form of glaucoma, affecting about three million Americans. It happens when the eye’s drainage canals wear out over time. The inner eye pressure (also called intraocular pressure or IOP) rises because the correct amount of fluid can’t drain out of the eye. With open angle glaucoma, the entrances to the drainage canals are clear and should be working correctly. The clogging problem occurs further inside the drainage canals, similar to a clogged pipe below the drain in a sink.

Most people have no symptoms and no early warning signs. If open angle glaucoma is not diagnosed and treated, it can cause a gradual loss of vision. Ultimately, patients can experience tunnel vison or become blind. This type of glaucoma develops slowly and sometimes without noticeable sight loss for many years. It usually responds well to medication, especially if caught early and treated.

What is the Treatment for Glaucoma?

Woman using eye drops
Eye drops can be a successful treatment

Most patients are successfully managed with topical eye drops—medications that they administer on a daily basis to prevent vision loss and lower their intraocular pressure. These patients come for frequent exams every 3-4 months to have their eye pressure checked.

Some patients benefit from laser surgery to lower the eye pressure and this allows them some freedom from frequent use of eye drops. Dr. Dealy will help each patient determine if they are a candidate or need laser treatment.

Diagram of Glaucoma Surgery
Diagram of glaucoma surgery

Other patients who have advanced glaucoma require surgical treatment of the disease. This is called a trabeculectomy and is an outpatient procedure done in the operating room. Again the aim of this therapy is to reduce eye pressure and preserve vision.

As of September 2013, Dr. Dealy will begin implanting the iStent, a new technology for the treatment of glaucoma


To schedule an appointment or for more information, please contact us.