Aplicativos por los que deberias empezar.

Chronic open angle glaucoma is treated with medication for as long as the medication keeps the pressure under adequate control. However, if the pres- sure does not hold at a safe level despite all attempts to control it with med- ication, or if a patient does not take the eyedrops as prescribed, then surgery is necessary. (Some ophthalmologists may perform laser or other surgery before this point is reached, but I don’t recommend it.)

The first approach is generally argon laser trabeculoplasty. In this simple office procedure, the laser is used to create multiple tiny burn spots all around the trabecular meshwork, the area of the drainage channels inside the eye. The burned areas contract as they heal, and this stretches open the drainage chan- nels, thereby allowing fluid to drain out of the eye more easily. On the average, the pressure is lowered about 7 millimeters of mercury, and the results may be long lasting. Generally, only about half of the trabecular meshwork is treated

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at a session, so the procedure can be repeated at least once if necessary. The results are usually better in people who have not undergone cataract surgery in the past. Only rarely may the pressure end up worse in the long term. In the short term, a pressure rise is a common complication. If the ophthalmologist checks the intraocular pressure an hour or two after the procedure, a high pressure can be detected right away and treated. Instilling a drop of apra- clonidine (Iopidine), a pressure-lowering medication, at the time of the surgery is also helpful in blunting any pressure spikes.

If the pressure cannot be controlled even with laser trabeculoplasty, some- thing more needs to be done. If a significant cataract in the eye is affecting vision and it is clear that cataract surgery would have

been required in the not-too-distant future anyway, then doing cataract surgery at this point is a way of lowering the pressure further. When done correctly, cataract surgery alone

often produces a striking reduction in intraocular pressure, and one or more of the glaucoma medications being used can often be discontinued. In many cases, this is preferable to combining cataract surgery with glaucoma surgery, because the risks associated with the combined procedure are definitely higher.

Conventional surgery for open angle glaucoma is called a trabeculectomy or filtering procedure. This operation is performed in the operating room, usu- ally under local anesthesia (an injection through the skin below the eye to numb the nerves going to the eye). A very narrow piece of sclera is removed close to the point where the cornea of the eye begins. This creates a passage- way through which the fluid inside the eye can bypass the usual drainage channels and exit the eye. The fluid forms under the conjunctiva, forming a shallow, blisterlike elevation called a bleb. From there, the fluid is gradually absorbed into the circulation. If the surgery is completely successful, the intraocular pressure remains under good control without medication. If it is partially successful, glaucoma medication may still be needed later on, but the pressure is much lower than it was before the surgery.

As with all surgery, complications can occur. Infection inside the eye is a rare problem but threatens the vision and the eye itself. Sometimes the surgery may not work because a good bleb does not form, and in this situation, the pressure in the eye remains high, just as it was before the surgery. In other cases, fluid may leave the eye too readily, resulting in a pressure that is too low

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Cataract surgery by itself often produces lasting reductions in pressure.

accompanied by a shallowing or even flattening of the anterior chamber of the eye. This problem may be caused by creating a surgical opening that is too large or by a leak through the conjunctiva. Of course, procedures exist for han- dling these problems, but sometimes additional surgery is necessary. Suffice it to say, filtering procedures should be done only on people who really need it. When filtering procedures are unsuccessful or cannot be done for one reason or another, procedures that partially destroy the ciliary body, which produces the aqueous humor, can be performed. One of these, cyclocryotherapy, involves appli- cation of an extremely cold probe to the outside of the eye over the area of the cil- iary body. This procedure can cause a fair amount of inflammation in the eye, and there is the danger that too much of the ciliary body will be destroyed, result- ing in an eye with little or no pressure, which can cause the demise of the eye.

Summary

Glaucoma is a chronic degeneration of the optic nerve, whose main risk fac- tor is a high IOP. Although the cause of glaucoma is unknown, it can be treated by drugs, usually in the form of eyedrops, which lower the pressure. These drops have an array of possible side effects. Very little research has been done to explore nutritional and other lifestyle factors that can affect IOP or that can prevent damage to the optic nerve more directly.

Engaging in aerobic exercise, the kind that gets you huffing and puffing, on a regular basis can cause a moderate decline in IOP and possibly reduce the need for medication. It may also reduce blood viscosity and thereby improve circulation to the area around the optic nerve. Therefore, exercise is good for your eyes as well as for your heart and lungs.

A few studies have suggested a relationship between smoking and glaucoma, but proof is lacking. Nevertheless, poor blood circulation to the optic nerve may predispose it to damage, so anything that can lead to poor circulation (includ- ing smoking) should be discouraged. Although chronic alcoholism is associated with nutritional deficiencies that cause the optic nerve to deteriorate, alcohol consumption in moderation is not considered a risk factor for glaucoma. In fact, drinking an alcoholic beverage can cause a transient lowering of IOP.

Drinking a large quantity (over a pint) of any liquid all at once can raise IOP, especially in people with higher pressures. The need for glaucoma patients to keep their IOP under good control at all times makes this an important consid-

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eration. Caffeine consumption in the form of coffee produces only a minimal rise of IOP in the average person, although some people may be more suscepti- ble to its effects than others. Caffeine can also reduce the circulation to the eye, an action that could have a negative impact on the health of the optic nerve.

Vitamin C in moderately high doses causes just a slight lowering of IOP in the average person. As with caffeine, though, we have to consider the possi- bility that a small percentage of people may show a very good response, so it may be worth trying. One study found that glaucoma patients had lower blood levels of vitamin B1than did people without glaucoma, but the signifi-

cance of this finding is unknown. We do not know whether taking thiamin supplements would be of any benefit. Rutin, which is not a vitamin but a flavonoid found in certain plants, may help lower IOP in some but not all patients taking pilocarpine or related drugs for their glaucoma.

People with glaucoma may have higher blood viscosity (thickness) than people without glaucoma. Therefore, substances that reduce blood viscosity and increase the flow of blood to the optic nerve may be useful. Omega-3 fatty acids (from flaxseed oil, fish oil, and other sources) and the herbal extract ginkgo biloba are both able to lower blood viscosity and may eventually prove useful in protecting the optic nerve from glaucomatous damage. A healthy diet and exercise can do the same. Ginkgo biloba was recently shown to increase blood flow to the eye.

The IOP over the course of a day may be affected by the timing of meals. The pressures are often higher just before meals and lower afterward. This tempts us to speculate that small, frequent meals might be more beneficial than the usual two or three large meals a day. An ultralow-fat diet may lower intraocular pressures, but how restrictive the fat intake needs to be to accom- plish this remains to be determined.

Surgery, by either laser or conventional means, is the treatment of choice for angle-closure glaucoma (iridotomy) but is more of a last resort in open angle glaucoma (laser trabeculoplasty and filtering procedures).

Recommendations

Since glaucoma is a silent disease whose incidence increases with age, regular examinations by a competent ophthalmologist are necessary both for detec- tion and for control. Prescribed medications should be used exactly as

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directed, and any adverse reactions should be reported to your physician. Other recommendations are as follows:

1. Avoid drinking more than two cups of water or other liquid over a short time.

2. Limit or avoid consumption of caffeine-containing coffee.

3. Alcohol consumption is all right in moderation, but try to avoid it for sev- eral hours before a pressure check.

4. Don’t even think about smoking!

5. Try taking vitamin C, 500 milligrams four times a day, and continue it only if a pressure check shows that the pressure has been significantly lowered.Avoid vitamin C, however, if you have a history of calcium oxalate kidney stones. 6. If you use pilocarpine in any form as treatment for glaucoma, try taking rutin,

50 milligrams three times a day, and continue it if it lowers your pressure. 7. Consider taking ginkgo biloba extract (Ginkgold), 60 milligrams twice a day.

Do not take it if you have a bleeding tendency or if you take the drug Coumadin. Aspirin and vitamin E can also increase your bleeding tendency. 8. Begin a program of aerobic exercise, such as stationary bike riding, if your

physical condition permits it and your physician approves it.

9. Make the transition to a low-fat (maximum 15 percent of calories), plant- based diet, rich in fresh fruits and vegetables, whole grains, and occasional nuts and seeds. Multiple, small meals over the course of a day are ideal.

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c h a p t e r e l e v e n

Diabetes

D

IABETES MELLITUS

,

A DISEASE MARKED BY HIGH BLOOD SUG

-

ars, is caused by either a lack of insulin or resistance to its action. It takes its toll on the entire body by affecting the blood vessels of the heart, kidneys, brain, and legs. It can also affect nearly every part of the eye. Diabetes has become an epidemic in Western countries.

We generally recognize two main types of diabetes. Insulin-dependent dia- betes mellitus (IDDM) usually begins in childhood and requires insulin injec- tions. In some people, the blood sugar is relatively easy to control, while in others, so-called brittle diabetics, the blood sugars may be wild and unpre- dictable. This type of diabetes is caused by the destruction of the cells of the pancreas that manufacture insulin. An autoimmune type of reaction, in which the body’s immune system turns against itself, is felt to be responsible. Infants who are breast-fed appear to be at reduced

risk, and some studies have indicated that cow’s milk proteins may play a role in trigger- ing the disease.1,2

Non-insulin-dependent diabetes mellitus (NIDDM) is the adult-onset form and is usu-

ally treated by diet alone or in conjunction with pills. It is characterized by a resistance of the body to the effects of insulin. Some think of it as the milder of the two types of diabetes, but the same complications affecting life and limb

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Adult-onset diabetes is almost unheard of in countries where people

eat high-fiber diets.

(literally) occur in both forms of the disease. About 80 percent of people with NIDDM are obese. A high-calorie, high-fat, low-fiber, meat-based diet is the cause. Not surprisingly, the disease is often accompanied by high blood pres- sure and high blood cholesterol and triglyceride levels, since these problems have the same dietary risk factors as diabetes. This deadly combination greatly increases the risk of heart disease and stroke in the diabetic patient. It is inter- esting to note that in developing countries where a high-fiber, low-fat diet is still routine, adult-onset diabetes is virtually unheard of. Even in the United States, Seventh Day Adventists, about half of whom are vegetarian, are reported to have only half the death rate from diabetes as the rest of the population.

In document 1.2 Obj. Conéctate (página 86-89)