Glaucoma (Open-Angle, Closed-Angle, or Congenital Glaucoma)

Glaucoma entails a buildup of fluid pressure in the eye's anterior chamber, which lies between the cornea and iris. The eye disease affects about one in 25 Americans, usually after the age of 40. About 85 percent of all cases are chronic open-angle glaucoma, in which the outflow of the clear fluid, called aqueous humor, gradually declines. As the pressure within the anterior chamber increases, the tiny blood vessels that nourish the optic nerve become pinched, causing the nerve to slowly wither and die. The eventual result is blindness. This type of glaucoma may start in one eye and then affect the other eye, with no early warning signs.

Closed-angle, or congestive, glaucoma, which accounts for less than 10 percent of occurrences, comes on rapidly when the iris is so expanded that it blocks the outflow of fluid. Within days, the eye becomes very red, hard, and painful, causing nausea, and severely disturbed vision, including blurring and halos. Such an attack must be treated as a medical emergency, because the high pressure quickly damages the retina and optic nerve, causing permanent blindness.

Congenital, or infantile, glaucoma, a rare birth defect, can also result in blindness if it is not treated early. In some unusual cases, glaucoma is secondary to an infection, tumor, injury, or other circumstance that blocks the outflow of aqueous humor.

Diagnostic Studies and Procedures

Because open-angle glaucoma generally has no obvious symptoms until it has already damaged the eye, about half of those with the disease do not know they have it. Early diagnosis, essential to prevent vision loss, is possible with a simple procedure called tonometry, in which a probe touches the eyeball to measure pressure in the anterior chamber. Tonometry should be part of a routine eye examination at least every other year after the age of 35. Although a puff of air may be used to measure eye pressure, this test is not as accurate as the probe. When pressure is abnormally high, further tests are necessary, including an evaluation of peripheral vision.

An ophthalmologist diagnoses acute congestive glaucoma on the basis of the sudden onset of symptoms, an eye examination, and tonometry. A doctor may suspect congenital glaucoma when a baby is born with or soon develops an enlarged, protruding eyeball.

Medical Treatments

Eye drops that keep the pressure at a safe level can usually control chronic open-angle glaucoma. The drops most often prescribed are timolol maleate (Timoptic), which reduces fluid production and increases its outflow, and pilocarpine (Pilagan and others), which increases outflow by reducing the size of the pupil. Alternatively, acetazo-lamide (Diamox), an oral medication, may be prescribed. Marijuana also reduces fluid pressure, but the medicinal use of this illegal substance is reserved for acute cases that cannot be treated by conventional means.

If medication alone fails or creates a problem with side effects, surgery may be performed, either traditionally or with a laser beam, to create an enlarged exit route for the aqueous humor. Or surgery may be used to implant a drainage valve. Sometimes a freezing probe is applied briefly to the portion of the eye that produces the fluid to decrease its output.

With acute glaucoma, the immediate objective is to reduce pressure. This is done with eye drops to constrict the pupil, thereby moving the iris away from the outflow ducts.

Massage of the eye may also stimulate fluid outflow.

These simple measures lend to provide only temporary relief. Usually another attack will occur unless surgery is performed. The most common operation is an iridectomy, in which a small hole is made in the iris to allow fluid to exit. A doctor may also advise this surgery for the unaffected eye, since anyone who has had an acute attack in one eye is likely to have one in the other.

Congenital glaucoma is also treated with surgery to correct the defect and preserve vision.

Alternative Therapies

Alternative therapies cannot cure glaucoma. People with chronic glaucoma should use alternate methods only to complement medical treatment.

Nutrition Therapy. Some studies indicate that vitamin C supplements and bioflavonoids, especially the antho-cyanidin compounds found in red and blue berries, may be useful adjunctive therapies for glaucoma.

Self-Treatment

The most important aspect of self-care with chronic glaucoma is to take all medications, including eye drops, precisely as prescribed. Avoid taking medications that raise intraocular pressure. These include tranquilizers and nonprescription cold and allergy pills and other drugs containing antihistamines or cortisone.

Other Causes of Vision Disturbances

Many disorders can cause halos, tunnel vision, blurred vision, and other symptoms similar to those of glaucoma. They include a detached retina, macular degeneration, a stroke or mini-stroke, and a tumor of the eye or brain. An eye injury or infection or the presence of a foreign object can also disturb vision.