Ординатура / Офтальмология / Английские материалы / The Eye Book A Complete Guide to Eye Disorders and Health_Cassel, Billig, Randall_2001

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pretty good understanding of the illnesses that can befall the rest of your body, and the ramifications of such ailments (diabetes, for instance) for your eyesight. Ophthalmologists can also be doctors of osteopathic medicine (D.O.). In addition, a board-certified ophthalmologist must have completed at least three years of residency training beyond the M.D. degree and passed extensive written and oral examinations in diseases and surgery of the eye.

Many ophthalmologists provide total eye care, beginning with the comprehensive medical eye examination: they prescribe glasses and contact lenses, diagnose eye diseases and disorders, and perform the appropriate medical, surgical, and laser procedures necessary to treat them. Other ophthalmologists perform eye exams and diagnose and treat diseases of the eye but limit themselves to a fairly narrow range of surgical procedures, referring patients needing different procedures to other ophthalmic subspecialists. And some subspecialists— doctors who concentrate on treating specific diseases and performing certain procedures (literally, they’re specialists within a specialty)—don’t perform routine eye exams at all.

Like many other branches of medicine, ophthalmology has become increasingly subspecialized over the last twenty years. Although some policymakers are fond of making the blanket statement that “there are just too many specialists,” the undisputed fact is that anyone (even, one suspects, those policymakers) who needs a surgical procedure wants the operation to be done by a

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surgeon who has performed that very same procedure many times—someone who does it every day, or at least several times a week, someone who is deeply familiar with every detail of the operation, and with every nook and cranny of that particular body part—rather than by a generalist whose job is to know a little bit about everything, who might have done that procedure only a few times before. (Which means, and we’ll make this point again in later chapters, that if and when you need a surgical procedure, consider getting a second opinion, and find the best, most experienced physician you can to perform it. Think about it: it’s your precious vision at stake here, and your one chance to get the job done right.) It’s also true that most surgeons want to do only the operations that they do really well. The situation is complicated, and it keeps changing.

Optometrists

An optometrist is someone who has earned a doctor of optometry (O.D.) degree after completing four years of post-graduate-level optometry school, following a four-year undergraduate college degree. Optometry school covers the structure and function of the eye, mechanisms of vision and optics, and the diagnosis and treatment of eye disease. Some optometry schools have even developed collaborative arrangements with medical schools to give optometry students the opportunity to develop a better understanding of how the eye relates to the human body and its overall condition.

Optometrists traditionally limited their scope of prac-

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tice to nonmedical treatment of eye problems. This included prescribing glasses and contact lenses to improve the quality of vision and the use of vision therapy to improve the overall functioning of the visual system. Optometrists were taught how to diagnose eye diseases and look for signs of associated systemic (“whole body”) diseases so that the patient could be referred to the appropriate physician. Currently, however, many optometrists are learning how and being licensed to treat noncomplicated eye disease and how to manage surgery patients along with ophthalmologists.

Opticians

An optician is an eye care professional licensed to fit, adjust, and dispense eyeglasses and other optical devices following the written prescription of an ophthalmologist or optometrist. In some states opticians can also fit and dispense contact lenses.

Recently, controversial legislation in many states concerning the use of diagnostic and therapeutic eye drops and procedures by optometrists has heightened the public’s awareness of the differences in training among ophthalmologists, optometrists, and opticians. Most eye care professionals, however, agree that each of these specialists has a separate yet complementary role in eye care— and in the future, you’re likely to see these three groups settling their differences and working more closely together. This will allow for a more comprehensive ap-

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proach to eye care, one that can also be cost-efficient for patients and their insurance companies, as well as for eye care providers.

How Often Should You Get Your

Eyes Checked?

This is what the American Academy of Ophthalmology recommends.

If you’re between ages forty and sixty-five: If everything’s fine—if you have no symptoms and are at low risk for eye disease—you should get a comprehensive baseline medical eye examination, to establish a point of reference for future checkups, and then go back for fol- low-up checkups every two to four years.

If you’re over sixty-five: Again, if everything’s fine—if you have no symptoms and are at low risk for eye dis- ease—you should have a comprehensive eye exam every one to two years. Why the need for more frequent checkups as you get older? Because, as with other ailments, your risk of developing certain eye problems such as cataracts, glaucoma, and macular degeneration goes up slightly with each passing year, and your best odds of maintaining good vision lie in catching any problems early, at the first signs of trouble.

If you have any symptoms of eye trouble: Even if you’ve just had your regular eye examination, it’s very important to get any new symptoms checked out right away. Symptoms of blurred vision, for example, can mean

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much more than that you just need to change your eyeglass prescription. Therefore, waiting for the next routine examination—especially if it’s two years away—is not a great idea. By then you might have some permanent vision damage from a problem that could have been much less serious if caught in time.

If you have other health problems or a family history of eye disease: In this case you’ll probably need more frequent eye exams. Remember, the eye isn’t immune from the repercussions of systemic medical conditions (hypertension and diabetes, for instance, can be particularly hard on the eyes). Also, if you have a family history of eye disease—glaucoma, cataracts at an early age, retinal detachment, or macular degeneration, for example—then your own risk of developing these is higher, and your doctor will want to be on the lookout for early signs or symptoms as you get older.

What You Can Expect at a Routine

Eye Examination

To begin the exam, the doctor or a member of the staff will take your medical history, asking a series of basic questions, beginning with your age (see box).

Visual Acuity Tests

After taking your medical history, the doctor will usually test your distance visual acuity and near visual acu- ity—how well you’re able to read letters correctly across the room, and how well you read them up close. (In years

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Your Medical History: Ten Important Questions about Your Health

Your eye examination will begin with your ocular history, followed by a few basic, important questions about your general health, beginning with your age. Although the questions may vary, you can probably expect to answer at least the following:

•What eye problems are you having now?

•What eye problems have you had in the past?

•How is your vision?

•Do you wear glasses? If so, do they work?

•Have you ever had eye surgery?

•How old are you, and how is your general health?

•What medical problems do you have?

•Do you take any medicines?

•Do you have allergies?

•Has anyone in your family had eye trouble or eye disease such as glaucoma?

•Has anyone in your family had diabetes, hypertension, heart disease, or thyroid disease?

past, the distance test was always done at a length of twenty feet, but today the test chart distance is generally downsized with mirrors, and visual acuity can be measured at a distance of sixteen or even fourteen feet, so don’t worry if the examining room seems small!) The

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classic “20/20” visual score measure means that at twenty feet, with or without corrective lenses, you can read the same letters that a person lucky enough to have perfect vision can read at twenty feet (see chapter 2). So a score of 20/40 on this test means that you see less well than normal (you must stand at twenty feet to read the same letters a person with perfect vision can read from forty feet), whereas 20/15 means your vision is better than normal (you can read from twenty feet away the same letters a person with perfect vision can only read at fifteen feet).

Usually, visual acuity, both distance and near—near acuity is measured at the usual reading distance of fourteen to sixteen inches—is recorded for each eye separately and for both eyes together. Some of these measurements may be skipped, depending on how much the doctor already knows about you. For example, in someone young enough to have normal accommodation, or focusing power, who has no trouble reading, recording near acuity may not really be useful.

Refraction

Refraction is the process by which the doctor determines the lens combination that helps you to see the best. Refraction can be done in several ways. One is for the doctor to hold up lenses and ask you questions (this is called subjective refraction or manifest refraction). Another is to shine a light into your eye and neutralize the movement of the light with lenses (a process called retinoscopy). Or your doctor may prefer to use one of several types of automatic refractors—computerized

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machines that estimate the lens combination that’s best for you. Subjective refraction is then often used to finetune your prescription, using your response to questions. After all, you are the best judge of how you really see.

All of these methods of refraction are useful under certain conditions, but none of them can be counted on in every circumstance or for every patient, which means that your doctor will need to determine which one is most accurate for you. For example, retinoscopy is invaluable for determining proper corrective lens strength for children or adults who cannot cooperate in subjective refraction. While most twelve-year-old children can participate in subjective refraction, only some ten-year- olds, and fewer still eight-year-olds, can do so. Automatic refractors are wonderful time-savers and do almost as good a job as subjective refraction. However, most of us who use the subjective refraction process are sure we do at least a little better than the machines. (And most of us are more interesting to talk to!)

Note: Just because the eye doctor can find a lens combination that provides the best possible visual acuity for you does not automatically mean that you must wear those lenses—or any lenses. Other than children with lazy-eye problems, no one has to wear glasses just because the doctor says so. People need to wear glasses only in order to correct the problems that bother them. Eye doctors are often surprised by the vision problems that people will tolerate in order to avoid wearing glasses. Going without glasses may seem silly to some people, but after all, they’re your eyes; even though you may squint a lot