What Everyone Should Know About Glaucoma

With more than two million sufferers nationwide, glaucoma is a leading cause of blindness in the United States. In fact, each year, glaucoma causes more than 12,000 Americans to lose their vision permanently and an additional 900,000 have experienced some form of vision loss or impairment. Moreover, it is estimated that fifty percent of those with glaucoma go undiagnosed.

Glaucoma comes without warning. Fluid buildup in the eye causes increased pressure, which can damage the optic nerve, the nerve responsible for sending visual images to the brain. Damage to the optic nerve usually occurs gradually and the effects are permanent.

Glaucoma is typically characterized by a loss in peripheral vision, followed by a loss in central vision and then, potentially, blindness. Although glaucoma often affects both eyes, it usually starts in one eye.

Glaucoma Has Many Types

There are three main types of glaucoma: open-angle, angle-closure and congenital. Open-angle glaucoma, the most common type, accounts for more than 90 percent of all glaucoma cases. Open-angle glaucoma progresses gradually and may go undetected because symptoms are typically mild until vision is lost. In most cases of open-angle glaucoma, early diagnosis and treatment can help prevent vision loss.

Angle-closure glaucoma is less common and is caused by a structural deformity in the eye. Angle-closure glaucoma is often inherited. Pressure within the eye builds rapidly because fluid is prevented from exiting the eye. Unlike open-angle glaucoma, angle-closure glaucoma causes more severe symptoms, which include severe pain, loss of vision and the appearance of rainbow rings around lights. If angle-closure glaucoma is left untreated, severe and permanent vision loss can occur within two to five days after the onset of these symptoms.

Congenital glaucoma, also caused by structural problems from birth, has genetic origins. Symptoms of congenital glaucoma include cloudy eyes, sensitivity to light and excessive tearing.

Risk Factors Associated with Glaucoma

Although glaucoma can affect anyone, there are certain groups who are at increased risk for the disease. African-Americans are at risk for glaucoma. In fact, this population is four to five times more likely than Caucasians to get the disease. Additionally, people over age 40, diabetics, people with high blood pressure and those with a family history of the disease are at increased risk.

People who have never been tested for glaucoma, are at increased risk for the disease, should get a glaucoma test from an eye care professional on a regular basis. The following timetable should be used as a guide for when glaucoma tests are suggested:

• At the ages of 35 and 40
• Every one to two years after age 35 for those in high-risk groups
• Every two to four years after the age of 40
• Every one to two years after the age of 55

Testing for Glaucoma

Because glaucoma has no signs in the early stages, regular eye screenings are the only way to find out if you have glaucoma. The tests usually take about ten minutes and are painless. Eye doctors check for the signs of glaucoma by measuring the level of pressure within the eye, checking the shape and color of the optic nerve disk (where the vision-carring nerves exit the back of the eye), evaluating the patient's field of vision and assessing the angle where the iris (colored part of the eye) meets the cornea. A comprehensive glaucoma screening includes three procedures:

• Tonometry begins by anesthetizing the eye. Eye pressure is then measured with a slit lamp that pushes a plastic prism lightly against the eye. Another version of the test uses a puff of air to measure pressure on the cornea; no anesthetic is needed.

• A Visual Field Test measures peripheral vision. Because loss of mid-peripheral vision is usually a first symptom of glaucoma, this test allows an eye doctor to diagnose the disease in its early stages.

• Ophthalmoscopy allows the eye doctor to look directly at the optic nerve. Using a hand-held flashlight-like instrument called an ophthalmoscope, an eye doctor can evaluate the color and appearance of the optic nerve.

Evaluated eye pressure is commonly treated with eye drops, which are taken daily. For the past 20 years, eye doctors have relied primarily on drugs called beta-blockers to reduce eye pressure. Although these treatments are effective, patients who suffer from asthma or certain heart problems cannot use them.

For patients who cannot tolerate other medications, doctors now have another option. XalatanÔ Solution (latanoprost ophthalmic solution) is the first of a new class of medications to treat open-angle glaucoma and ocular hypertension in patients who are either intolerant of other intraocular pressure-lowering medication or who do not respond sufficiently to another intraocular pressure-lowering medication. It appears to work by increasing drainage of fluid rather than slowing production of fluid in the eye. Xalatan is taken once daily at night. The most frequent reported side effects of glaucoma patients who were treated with Xalatan include blurred vision, burning and stinging, conjunctival hyperemia, foreign-body sensation, increased iris pigmentation, itching and punctate epithelial keratopathy.

In some cases, patients may require conventional surgery or laser therapy to improve fluid drainage from the eye.

Remember, early detection of glaucoma is key to managing the condition. A quick and painless glaucoma test can prevent the onset of blindness associated with this potentially sight-robbing disease.

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