Ординатура / Офтальмология / Английские материалы / The Eye Care Sourcebook_Lavine_2001

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adhesions, which we call synechiae. The formation of synechiae is undesirable because they not only distort the pupil but also can form in a continuous band around the entire pupil. This prevents the aqueous humor from being able to travel through the pupil into the anterior chamber of the eye, where it can drain out in the normal manner. If this happens, a severe pressure rise, a form of glaucoma, occurs. Synechiae can also form in the front of the eye in the angle where the iris meets the cornea. This is where the drainage channels of the eye are, so synechiae in this region can also cause glaucoma.

We check the lens for the presence of cataract. Both the uveitis itself, if left unchecked, as well as the treatment for it—corticosteroid medication—can cause cataracts.

We also examine the vitreous to detect the presence of cells. If we see cells, then we know that vitritis is present. Sometimes vitritis can coexist along with iritis, and sometimes it may be present by itself.

The pressure in the eye with iritis is frequently lower than in the normal eye. This occurs because inflammation suppresses the formation of aqueous humor. However, the cellular inflammatory debris created by the iritis can sometimes clog up the eye’s drainage channels. If this occurs to a significant degree, then the pressure may actually be higher in the involved eye.

We then examine the retina closely. Some forms of infection, such as toxoplasmosis or cytomegalovirus, may cause retinitis, which is usually easy to discern. The blood vessels coursing over the retina are also examined for signs of vasculitis. Finally, we examine the macula for the buildup of fluid that can be seen with moderate to severe uveitis.

Determining the Causes of Uveitis

In someone who (1) has iritis in both eyes, or (2) has iritis that has recurred in one eye, or (3) has vitritis along with iritis, or (4) has the chronic, insidious form of uveitis, we generally do special testing to look for the cause, guided by the patient’s past medical history.

Does the person have any symptoms of arthritis in the spine, such as stiffness on getting up in the morning? An X ray of the spine may yield subtle clues about the presence of arthritis. Genetic testing can also determine whether the person has a tendency for this form of arthritis, as well as for iritis. Does the person have any symptoms suggesting urinary tract inflammation? Reiter’s

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syndrome is a disease of uncertain cause marked by iritis, occasional conjunctivitis, arthritis, and urethritis (inflammation of the urethra). Is there any chance the person could have acquired a venereal disease? Syphilis is easy to test for and easy to treat should it be present. Is there a history of tuberculosis? A skin test for TB and a chest X ray may provide important information. Does the person have a form of colitis, such as ulcerative colitis? Are there any skin lesions suggestive of psoriasis, another cause of iritis? Could sarcoidosis be present? This is a poorly understood inflammatory disease that can affect many parts of the body. A blood test and X rays can help in the diagnosis. Does the person have an immune system problem, either from a disease like AIDS or as a result of chemotherapy or organ transplant medication? Cytomegalovirus is a cause of infection of the retina and uveitis in patients with immune system disorders. Are there scars on the retina characteristic of old toxoplasmosis infection? (Toxoplasma is a one-celled parasitic organism acquired prenatally from one’s mother, from infected cat litter, from eating meat, and so on.) It is important to diagnose any underlying medical problem causing the uveitis, because eradication of the uveitis may depend on appropriate treatment of the causative medical condition.

Treating Uveitis

Two types of treatment exist: nonspecific treatment to quell the inflammation, and specific treatment of any underlying medical problem.

Nonspecific treatment invariably involves dilation of the pupil with eyedrops. These drops are called cycloplegic eyedrops. They temporarily paralyze the sphincter muscle of the iris, thereby allowing the pupil to dilate.

They also temporarily paralyze the ciliary body, which contains the muscle the eye uses for near focusing. These actions accomplish two things: (1) They put the eye at rest, reducing the pain and light sensitivity caused by muscle spasm; and (2) they can break synechiae (adhesions) that have formed between the iris and the lens and can hopefully keep new synechiae from forming. Cycloplegic eyedrops vary in strength and duration of action, but their bottles always have red caps for easy identification. Cycloplegics commonly used include atropine, scopolamine, homatropine, cyclopentolate, and tropicamide.

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Nonspecific treatment also includes corticosteroid (cortisone) medication. Corticosteroids inhibit the inflammation by a number of mechanisms. They are available in both eye drop and ointment form, and they come in different strengths. Prednisolone acetate 1 percent is one of the most potent, while predisolone acetate 1⁄8 percent is a weaker preparation. Ointment tends to be used only at bedtime to avoid blurring of vision during the day. Initially, the drops may be prescribed anywhere from three times a day to hourly.After the inflammation has responded, the drops must be slowly tapered rather than stopped suddenly to avoid rebound inflammation. Eyedrops or ointment such as this is used when iritis is present. If the uveitis consists of vitritis only, these medications are generally not effective because they don’t penetrate into the back areas of the eye.

When vitritis is present, the corticosteroid medication is delivered by other means. One way of accomplishing this is to give an injection right next to the eye. We call this a subconjunctival injection, because the medication is injected under the conjunctiva. The corticosteroid medication is gradually released from this location and reaches all parts of the eye. Some studies indicate that this is the most effective way of getting corticosteroid drugs into the vitreous. A subconjunctival injection causes just mild discomfort at the time it is given, but the eye usually feels quite sore over the next twenty-four hours. People sometimes say it feels as if they had been kicked in the eye by a mule (or at least what they imagine that would be like).

The alternative to a subconjunctival injection is to take the corticosteroid medication by mouth, something occasionally done if the uveitis involves both eyes or if the patient refuses to have an injection. This approach not only delivers the medication to the eye but also subjects the entire body to significant amounts. Corticosteroid medication can

cause numerous side effects. In the eye, it can raise the intraocular pressure, causing secondary glaucoma that can damage the optic nerve, and it can cause cataracts after months

of use. All forms of corticosteroids, whether given as eyedrops or delivered into the body as a whole, can cause these eye problems. However, systemic corticosteroids (given by mouth or by intramuscular or intravenous injection) impair the immune system, increasing the risk of serious infection, especially after prolonged use. An inactive tuberculosis infection in the lungs can suddenly become active. Corticosteroids delay and interfere with healing. Psychological

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effects, including depression, may occur. People sometimes eat ravenously and gain weight. Fluid retention can develop. The blood sugar may become elevated in susceptible people, blood pressure may rise, and peptic ulcers may recur. In rare cases, the hip joints or the kidneys may be severely damaged.

Because of this multitude of possible side effects, we never prescribe large doses of corticosteroids without carefully evaluating the benefit/risk ratio. However, in many cases, corticosteroids are definitely indicated, especially when losing an eye is a possible consequence of not using them. If you are taking corticosteroids, report promptly any symptoms you think you may be having to your doctor.

In some people, the uveitis does not resolve completely with treatment, or it recurs as soon as the medication is tapered down. These individuals may need to continue corticosteroid treatment at the lowest possible dosage indefinitely. Obviously, it would be nice if we had a safer long-term alternative to corticosteroids. The nonsteroidal anti-inflammatory drugs (NSAIDs), commonly used for arthritis, have been tried, but without much success.

One patient of mine suffered from a chronic uveitis (primarily vitritis) in one eye that was presumably caused by her sarcoidosis, an inflammatory disease that can also cause lung problems, among other things. She required corticosteroids by mouth, and whenever I tapered her below a certain level, the uveitis surfaced again—very frustrating. Finally, I suggested she take some ginkgo biloba extract at 80 milligrams three times a day—double the usual dose, in addition to her corticosteroid. This extract has a mild inhibiting action on platelet-activating factor, a substance involved in inflammation. I slowly tapered her off her corticosteroid, except that this time, her uveitis did not flare up again! One day, she returned to the office complaining of symptoms in her eye along with a flare-up of her lung problems from the sarcoidosis. The uveitis had returned. On questioning her, I found that she had absentmindedly stopped taking the ginkgo biloba on her own, and the recurrence of both of her problems followed soon thereafter. I put her back on the same regimen, and once more I was able to taper her off the corticosteroids by maintaining her on the ginkgo biloba.

Obviously, the previous anecdote is simply that—an anecdote. We can’t say for sure that the ginkgo biloba had a beneficial effect. But it might have,

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and it certainly deserves further study. Ginkgo biloba certainly does not have the anti-inflammatory strength of corticosteroids and should not be used in place of them. But simply to try the ginkgo

biloba as a supplement seemed warranted, considering the potential hazards associated with long-term corticosteroid use.

While we’re talking about “natural” treatment modalities, we should talk about general supportive measures for the patient with uveitis. Avoidance of any stress, physical or emotional, is important. A major physical stressor is lack of adequate rest. Make sure you get enough sleep every night. Eat a balanced diet with plenty of fruits and vegetables. I have seen many patients with immune-mediated inflammatory disorders who suffered a major setback when their bodies became stressed for one reason or another.

Treating Specific Causes of Uveitis

When someone is found to have a previously undetected medical problem that is now causing uveitis, the internist or family physician must often share in the care with the ophthalmologist.

Treating the uveitis may not always necessitate treatment of the underlying problem. Ankylosing spondylitis, a form of arthritis in the spine, affects 1 out of every 500 to 1,000 people and is more common in men than in women. The iridocyclitis (both iritis and cyclitis) is treated nonspecifically with cycloplegic and corticosteroid eyedrops. Psoriasis affects primarily the skin but can also cause arthritis and uveitis. Again, nonspecific treatment of the uveitis is all that is necessary. The same applies to Reiter’s syndrome (arthritis, urethritis, conjunctivitis, and iridocyclitis) and inflammatory bowel disease (ulcerative colitis and Crohn’s disease).

Syphilis is a venereal disease that has always been much less common than others, such as gonorrhea or chlamydia infections. But the bacterium responsible for syphilis causes a chronic infection in the body that can affect many organ systems, including the brain, spinal cord, eyes, and heart. Congenital syphilis causes a number of deformities in the newborn infant, but syphilis acquired during life is quite serious as well. A syphilis infection can go through several stages, termed primary, secondary, and tertiary syphilis. Primary syphilis can cause a sore on the genitals that eventually resolves. Secondary syphilis

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includes other manifestations that occur as the bacterium spreads throughout the body. Tertiary syphilis involves the late, most serious complications. Uveitis is a common manifestation of secondary syphilis, and a blood test for syphilis is almost always part of the medical testing done for uveitis. If the blood test is positive, then additional confirmatory tests, sometimes including a spinal tap, are done. Penicillin or another antibiotic is then administered in high doses.

Although we generally do not see uveitis associated with rheumatoid arthritis in adults, it is a common feature of juvenile rheumatoid arthritis. Interestingly, those children who only have a few joints involved have a much higher risk of developing iridocyclitis than do those whose arthritis involves many joints. Often, the iridocyclitis occurs in what seems to be a quiet eye, causing no symptoms at all, and a significant amount of damage can occur to the eye by the time the iridocyclitis is diagnosed. Therefore, children who are felt to be at high risk should undergo routine screening eye examinations.

Sarcoidosis is a chronic inflammatory disease that affects the lungs, bones, eyes, and other tissues. It can cause a chronic uveitis, often primarily involving the vitreous of the eye, and may occasionally affect the optic nerve or retina. Chest X rays sometimes show large, calcified lymph nodes between the lungs. A blood test may show a high level of angiotensin-converting enzyme. Other blood test abnormalities are occasionally found as well. If the eye appears to be involved, the inside lining of the lower eyelid can be biopsied, especially if any small nodules appear to be present there. The biopsy result may support a diagnosis of sarcoidosis. Treatment of any uveitis is nonspecific, however, as corticosteroids represent the only form of treatment for sarcoidosis.

Toxoplasmosis, a parasitic infection caused by Toxoplasma gondii, is a cause of retinochoroiditis, an infection primarily of the retina and secondarily of the choroid layer of the eye. (See “Toxoplasmosis,”page 224.) Pregnant women can transmit it to their offspring, and it is most commonly acquired by eating undercooked meat or by coming into contact with the litter of infected cats. In some cases, a marked uveitis can accompany the retinochoroiditis, sometimes severe enough to obscure the view of the retina. The uveitis and retinal inflammation are treated by high doses of oral corticosteroids, while the infection of the retina is treated with combinations of antitoxoplasmosis drugs, which include sulfa drugs, pyrimethamine, clindamycin, and the tetracyclines. The corticosteroids impair the immune system, of course, but their use is essential if the sight and the eye itself are to be saved.

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Headaches

Eye problems cause headaches less frequently than most people think. In most people, the mild blurring of vision that necessitates a change in glasses does not cause headaches. Eye muscle problems may occasionally cause headaches. The most common of these would be a convergence insufficiency, a weakness of the muscles that turn the eyes inward. (See page 107.) Many headaches feel as though the pain is located in or behind the eyes, but that does not necessarily mean that there is an eye problem. Also, rest assured that a feeling of pressure in the eyes is not a sign of glaucoma (unless the eye pressure is extremely high, which is rare).

Headaches may result from a number of causes, including migraine, allergy, elevated fluid pressure around the brain, circulation problems to the brain, and head injuries. But the most common cause of headache, by far, is muscle tension.

Muscle Tension Headaches

Muscle tension headaches often result from stress. Some people handle stress better than others do. For people who have no outlet for their stress, the stress may become localized in the muscles of the head, including those that surround the eye. Muscle tension headaches are

not associated with any particular activity, such as reading (unless the reading material is very stressful!). In fact, people often wake up with the headache. So much for restful sleep.

Sometimes a stressful event causes a headache, but even after the stressful event is gone, the headache remains. This type of chronic headache may persist until the vicious cycle is broken.

One form of muscle-related headache is called greater occipital neuralgia. This is a kind of headache pain that follows the distribution of certain nerves on the head. People who have greater occipital neuralgia typically complain of pain in or behind the eye, but on examination, they have an area of tenderness on the back of the head right at the base of the skull. Why should muscle tension in the back of the head cause eye pain? It has to do with a phenomenon called referred pain. This means that when people experience a problem along

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one branch of a nerve, they often experience and localize the pain as though it were coming from a location in the territory of one of the other branches of that nerve. In the case of greater occipital neuralgia, the same nerve that sends a branch to the muscles at the back of the skull also sends a branch to the muscles near the eye. When the muscle in back goes into spasm and pinches the nerve, the person feels it in the eye. Greater occipital neuralgia can be caused by stress-related muscle tension, although it may sometimes be associated with arthritic problems in the neck.

Eliminating muscle tension headaches may not be easy,but you can try a number of approaches. Obviously, if there is a source of stress in your life, such as jobrelated stress, you can take steps to eliminate it. You can also work at reframing things in your mind so that they don’t bother

you as much. For example, if you are stressed out by having to wait in lines or in rush hour traffic, try to look at it positively. Think of it as

an opportunity to improve yourself by developing the attribute of patience. Or consider it an opportunity to think through in your mind some dilemma you’ve been facing. Things are stressful only if you allow them to be stressful to you.

Muscle relaxation techniques are very useful. Many of us walk around with tensed muscles without even being aware of it. The remedy for this is to get in touch with your body and become aware of how it is behaving. Try this. Lie down in bed on your back with your legs uncrossed, or just sit back in your chair, and breathe slowly and deeply, in and out. Try to relax completely. Begin with your toes and your feet. Are they completely limp? If not, allow them to relax. Then mentally move up to your ankles, legs, and thighs. Allow them to loosen up and become completely relaxed. Then concentrate on your abdomen. Allow it to follow the pattern of your breathing. Allow the outward movement of your abdomen to draw in your every breath. Then relax your fingers, hands, arms, and shoulders. If they are tense, become aware of that tension and learn to recognize when those muscles are tense and when they are not. Then concentrate on your neck and head. Let them completely relax. Is your forehead drawn into furrows? If so, relax your forehead muscles and note the difference. This type of muscle relaxation exercise should be done not only whenever you are showing signs of tension, but also routinely, to keep yourself from tensing up.

Massage, biofeedback, even acupuncture—many other techniques may be worth trying. Should you take pain medication? You should when necessary, as it

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may also help break the cycle of pain and muscle spasm.Avoid addictive prescription medications,however. Learning to become aware of tight muscles and to relax them is more effective in the long run and certainly a healthier alternative.

Migraine

Migraine is a common disorder, affecting one out of six women and about one in twenty men. Migraine headaches are sometimes called vascular headaches, referring to the fact that they involve both constriction and dilation of blood vessels of the brain during the headache’s various phases. Many forms of migraine exist. In classical migraine, the person experiences visual changes, called an aura, followed by a headache. Some people can get the headache without experiencing the aura, while others may have the aura but not get a headache. Migraine without a headache? Exactly. We call this acephalgic migraine. (Cephalgia is the medical term for headache.) Some people have the aura followed by headache when they are younger, but then have the aura without a headache when they become middle-aged or older.

When I see people who I suspect may be suffering from migraine, I always ask them two questions. First, do you have car sickness now, or did you as a child? For some reason, a history of motion sickness is somewhat more common in migraine sufferers. Second, do you

get a headache when you eat something that is very cold? Experiencing pain, usually on the forehead between the eyes, after eating

something cold is strongly correlated with migraine. They are often termed ice-cream headaches. What I have found to be very interesting is that most people who answer yes are puzzled about why I asked. They assume that everyone who eats ice cream gets a pain in the head! Apparently, it is not a common topic for discussion. In my experience, it is unusual to find someone with migraine who does not give a history of ice-cream headaches.

Symptoms of Migraine The aura of migraine may be difficult to understand for people who have never experienced it. Visual changes are the most common manifestation of the migraine aura because the arteries that supply the part of the brain that controls vision are the ones most likely to constrict. However, other parts of the brain can occasionally be affected, producing tran-

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sient paralysis of one side of the body or perhaps involving one of the nerves that controls eye movement, causing double vision. In any case, the aura usually lasts less than an hour.

Visual auras usually involve blind spots in either the left or right half of the field of vision of each eye. The auras often include what we call scintillations, jagged lines or abstract figures of varying configurations that may not be too noticeable at first but then become more prominent while enlarging and flickering wildly. People who experience the aura often have to stop what they are doing and just close their eyes. The blind spots can be quite frightening, especially the first time they are experienced. Although the vision generally returns to normal at the conclusion of the aura, rarely one may find permanent damage as one would see in someone who has suffered a stroke. For example, one might occasionally see a Horner’s syndrome in someone who has suffered repeated attacks of migraine. Horner’s syndrome refers to nerve damage that causes a mild drooping of the upper eyelid and a slightly smaller pupil in the eye on that side. Rarely, people may also complain of small, permanent blind spots.

I had a patient, a smoker, who suffered from migraine. During the aura of one attack, the vision completely blacked out on the left side of his vision in each eye. Unfortunately, it never returned. He was left with this disabling loss of vision, possibly because the blood vessel spasm associated with smoking prolonged the constriction of his arteries and resulted in a stroke in the vision part of his brain. A word to the wise is sufficient.

Some physicians are puzzled when they see the occasional patient who has the migraine aura but no headache thereafter. Although this phenomenon, acephalgic migraine, is well known to oph-

thalmologists and neurologists, the average physician may not be aware of its frequency or the fact that it even exists. But what about the middle-aged or elderly patient who

develops what sounds like a migraine-related aura, even though that person has never experienced a migraine in the past? Migraine usually begins in children or young adults. To occur for the first time in older people is unusual.

Visual changes that may be very similar to the auras of migraine may be seen in adults experiencing circulation problems to the brain because of hardening

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