Understanding glaucoma

If you've actually been diagnosed with glaucoma — a condition that can lead to blindness — count yourself lucky. You can take action and these guidelines will show you how.

Having glaucoma means that the fibres of your optic nerve are beginning to die off, most likely due to excessive fluid pressure inside your eye. This problem, called increased intraocular pressure (IOP), is caused by a watery fluid (aqueous humour), which normally fills your eyeball and produces IOP in the same way that air from a pump creates pressure in a tire.

To keep the pressure at a safe level, some fluid constantly drains out through a sieve-like network of connective tissues called the trabecular meshwork, or through an alternate drainage system called the uveoscleral pathway. It then empties into a drainage channel, located where the iris and the cornea meet; this area of the eye is known as the drainage angle.

When anything prevents the aqueous fluid from draining, pressure increases in your eye and eventually kills nerve cells. If the condition isn't treated with medication or surgery, your peripheral vision — your ability to see objects at the very edge of your visual field — will begin to disappear. As even more cells die, your central vision will go as well. The final result is total, irreversible blindness.

In Canada, the most common type of glaucoma (some 90 percent of cases) is open-angle glaucoma, which occurs when the trabecular meshwork becomes partially blocked for reasons that are unknown. Although the drainage angle remains open, the aqueous humour drains out too slowly, leading to fluid backup and a gradual but persistent elevation in pressure.

You can have this condition for years before it becomes noticeable. Another, far rarer variation is called closed-angle glaucoma. This condition, which causes intense pain and other symptoms, can happen suddenly; it is a medical emergency, and you need to get immediate treatment.

Exactly which biological mechanism actually triggers glaucoma remains a mystery, but there are a few suspects. One is a natural body process called apoptosis, during which cells commit suicide. This may contribute to the pressure in open-angle glaucoma by reducing the number and activity of the cells in the eye’s drainage channel.  Another possibility is low blood pressure or other circulatory problems, which reduce blood flow to the optic nerve.

• Specialized tests to determine the level of pressure in your eyes and indicate how far the disease has progressed.
• Eyedrop medications to bring pressure inside your eyes under control.
• Surgery only if medications don't work or cause problematic side effects.

1. Try vitamin E. Although there is no evidence to show that it works directly on glaucoma, this nutrient is often recommended by doctors for its ability to clean up the destructive oxygen molecules known as free radicals, which roam through your circulatory system. Vitamin E may also help improve your visual field. The standard dosage, in capsule form, is 400 IU a day.
2. Sit still and relax. Meditation, biofeedback and other approaches to relaxation seem to have some therapeutic effects on glaucoma, although no one knows why.
3. Keep your head up. Anything that requires you to be in a head-down position, such as bending over to tie your shoes or practicing certain yoga poses like head or shoulder stands, may increase your IOP. Try to keep your forehead from dropping lower than your chin for any extended length of time.