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What Is Glaucoma?

Glaucoma is a common degenerative eye disease that is caused by damage to or excessive pressure on the optic nerve. Nearly 3 million Americans suffer from this disease, but only about half are even aware that they have the disease. The most common form of glaucoma is known as primary open angle glaucoma, or POAG. Closed angle glaucoma, a rare form of the disease, is very serious and requires emergency intervention. A third form of the disease is known as “low tension” glaucoma, a condition in which the patient may have optic nerve damage but have normal intraocular pressure. Without treatment, any form of glaucoma can result in vision loss or blindness.

Symptoms of Glaucoma
Although treatable when caught early, glaucoma has no early warning signs. Until its advanced stages, most patients have no indication that the pressure in their eyes may be elevated or that their optic nerve may be damaged. The disease affects peripheral vision first—meaning you could have “perfect” 20/20 vision but still have glaucoma. In POAG, peripheral vision is gradually lost, while central vision is usually spared. Those with POAG might notice excessive fluid in their eyes. Open angle refers to the eye’s drainage system being open, but it is still not able to drain the fluid as fast as it is produced. Although closed angle glaucoma is rare, its symptoms typically include red, painful eyes, blurred vision, headache, and nausea. This form of the disease is an ocular emergency requiring immediate treatment.

Who Is At Risk?
Those who are most at risk of having glaucoma are people with elevated intraocular pressure. The symptoms of glaucoma are not noticeable until the advanced stages, and the risk of having the disease increases with age. Anyone who is over the age of 60 is at risk of having glaucoma. Having a relative who suffers from glaucoma is another risk factor. Those who are of African descent, in addition to being over the age of 40, are at risk for having the disease. Anyone who has diabetes is also at risk for having glaucoma. People in these ‘at risk’ groups won’t experience any noticeable symptoms of the disease early on, so it is important to have regular eye examinations.

Diagnosing Glaucoma
Dr. Earle diagnoses glaucoma as part of a routine eye examination. The eye doctor will examine the optic nerve for damage and measure the intraocular pressure in the eyes, a painless procedure called tonometry. If glaucoma is suspected, the doctor typically gives the patient a vision test to determine visual acuity for central and peripheral vision. The test takes about 20 to 30 minutes to perform and consists of flashes of light that the patient sees or does not, with the patient pushing a button to alert the doctor when a flash is seen. This method allows the doctor to accurately map the patient’s visual acuity and find the areas where vision may be affected. Checking intraocular pressure alone is insufficient to diagnose glaucoma. To protect your vision, it is essential to have early and regular eye examinations.

Treating Glaucoma
Once a diagnosis of glaucoma has been made, treatment depends on the form of the disease and its severity. For primary open angle glaucoma, eye drops are often given to lower the intraocular pressure. Lowering the pressure in the eye may help slow damage to the optic nerve. For closed angle glaucoma, eye pressure must be reduced quickly, either by eye drops or intravenously. In addition, laser surgery may be required to open the eye’s drainage system to allow fluid to drain.
For those cases of glaucoma that have not responded well to other treatment methods, or for patients who are not candidates for laser surgery, traditional surgery is usually recommended. The most common type is filtering surgery, also known as trabeculectomy. During the procedure, a small flap is created in the sclera (white of the eye), allowing for fluid drainage. To keep the flap from healing and closing, anti-scarring medicine is also administered. More than 85 percent of patients find this surgical method successful. Another surgical option is valve implantation. During this procedure, a silicone tube is placed in the front chamber of the eye. Fluid then drains through the tube to a small reservoir on the side of the eye. This method has a success rate greater than 80 percent.

Preventing Glaucoma
The best way to keep glaucoma from robbing you of your eyesight is to have early and annual examinations with Dr. Earle. Simple and painless, an eye exam will alert you and your eye doctor early on so that an appropriate course of treatment can be taken. Early detection of glaucoma means more effective treatment of the disease. If you notice any of the following warning signs of glaucoma, please contact your eye doctor immediately:
• Loss of peripheral vision
• Blurred vision
• Red, painful eyes
• Halos around lights
• Headaches
• Nausea