GLAUCOMA: 'SILENT THIEF OF SIGHT'

Dixie Wilson of Sikeston was examined by the biomicroscope or slit lamp microscope that tests eye pressure and can examine the structure of the eye to determine how well the fluid in the eye is draining.

Dixie Wilson of Sikeston recently had a routine eye examination at the Regional Eyecare Center in Cape Girardeau.

Though it isn't unusual for Wilson to have an eye exam at this time of year, a past diagnosis made after her routine exam likely saved Wilson's sight.

Dr. Beverly Cleair of the eye center diagnosed Wilson with a rare glaucoma.

Glaucoma quietly steals a person's sight by slowly eroding the peripheral vision. The common or open-angle glaucoma generally has no symptoms and can only be detected during an eye examination.

There are some 67 million people with glaucoma -- 4 million Americans. So far, 100,000 Americans have gone blind in both eyes because of the disease. Another 50,000 people will be diagnosed with glaucoma this year, and 1,000 of them will go blind.

Wilson, who maintains a busy schedule managing the rental properties she and her late husband, Jim, had purchased over the years, was lucky. Her narrow-angle glaucoma was treatable through surgery.

Most open-angle glaucoma is treatable with eye drops and medicines, if it gets diagnosed early enough.

Glaucoma occurs when the normal fluid pressure inside the eye progressively increases, leading to optic nerve damage and reduced peripheral vision, according to the National Eye Health Education Program.

While common glaucoma can be controlled, there is no cure yet and the blindness that had occurred from glaucoma cannot be restored, Cleair said.

Several years ago Wilson had come to Cleair to get contact lens for a severe case of astigmatism, and Cleair had helped her adjust the contact lens. Since then, Wilson has regular eye examinations, usually every six months.

The regular eye examinations and the timing of her examination in late 1994 saved her from blindness, Cleair said.

That's when Cleair noticed Wilson's eye pressures, normally nine and 11, had jumped to 21 and 23. Normal eye pressures are in the mid-teens, 16 to 18.

In the normal eye, aqueous humor -- a clear, nutrient-rich fluid -- passes continuously through the pupil and into a small space at the front of the eye, called the anterior chamber, a handout said. As the fluid leaves the anterior chamber, the aqueous humor flows to the periphery of the chamber, or drains into blood vessels in and near the sclera, the white outer coat of the eye.

In open-angle glaucoma, the aqueous humor drains too slowly through the open channel system, creating a chronic rise in fluid pressure inside the eye. This elevated pressure may gradually interrupt the metabolic processes of cells in the optic nerve, leading to a progressive destruction of nerve fibers that are essential for vision.

In the narrow-angle glaucoma, part of the iris suddenly obstructs the angle and blocks the aqueous humor from reaching the drainage system. This often causes a very painful rise in eye pressure and emergency medical attention is needed.

The difference between open-angle and narrow-angle or closed-angle glaucoma is that in the open-angle glaucoma the drainage channels are open but the fluid does not drain properly. In closed-angle glaucoma, the drainage channels are blocked or closed and the fluid cannot go through the channels.

Cleair said it was the sudden jump in the eye pressure that led her to check for glaucoma. She used a biomicroscope or slit lamp microscope that told her Wilson had a rare form of glaucoma called narrow-angle glaucoma.

What Cleair found through the test was that Wilson's drainage channels in the eye were too narrow.

Wilson had no symptoms, and Cleair said she thinks it was caught in time because the pressure in Wilson's eyes hadn't gotten high enough to cause problems.

Cleair had helped Wilson set up an appointment with Dr. Richard Kies of Cape Girardeau whose own tests confirmed the narrow-angle glaucoma and who recommended laser surgery to correct the problem. The surgery was completed in February 1995.

Basically, in the laser surgery, a high-energy beam of light makes about 100 tiny burns on the meshwork of the anterior chamber's drainage system. The burns stretch the existing holes in the meshwork to allow for better fluid drainage.

Had Wilson's condition not been discovered when it was, her problem would have increased and she would have experienced fuzzy vision, seeing halos around objects and nausea, Cleair said.

Wilson, for the time being is cured of narrow-angle glaucoma. Her eye pressure has stabilized at about 20, which Cleair said is on the high side of normal.

Wilson is still a high risk for open-angle glaucoma, Cleair said.

Open-angle glaucoma is a risk to anyone, but certain groups are more susceptible. People who are more at risk are those with a family history of glaucoma, African-American, older than 45, have diabetes, have had a previous eye injury, have myopia and have had a long exposure to cortisone products.

Statistics show blacks are six times more likely to get glaucoma than whites, and blacks develop the disease at an earlier age, around 40, than whites. Whites generally develop the disease around age 60.

In blacks, the disease develops more rapidly and severely than whites. By age 70, 1 in 50 whites will develop glaucoma; in blacks, the rate is 5 in 100.

The age factor of people in developing glaucoma is dramatic. At age 45, the ratio is 1 in 100; by age 60, it's 2 1/2 in 100; and by age 75, it's 5 in 100.

That might be why the Regional Eyecare Center conducts glaucoma screenings for the elderly throughout the year.

Cleair said three tests in the general eye examination help determine if glaucoma is present. They are the eye pressure test, the check of the eye's drainage system, and the test to determine the health of the optic nerve. If there are problems with any of these areas, then a visual field test, side vision test, will be administered to determine if a patient has lost any peripheral sight.

January is Glaucoma Awareness Month, and the Regional Eyecare Center has mailed patients information about glaucoma and has given people who have come to the center a glaucoma questionnaire.

Because Wilson's father had glaucoma and because of her age, she remains at risk for open-angle glaucoma.

So, her doctor requires that she have an eye examination every six months, have at least one side vision examination a year and visits a glaucoma specialist in St. Louis once a year.

For now, though, Wilson is clear of any glaucoma and continues her busy schedule managing her rentals.