A CHILD'S EYES
ForewardOne of the defining characteristics of medical care delivery in the coming era is restriction of access to specialized care. What this means to primary care physicians -- to pediatricians and family practitioners – is new responsibility to diagnose and to treat medical problems formerly the province of more specialized physicians. One of the new challenges is that they must decide who should be referred to specialists in pediatric ophthalmology. And increasingly, they must assume the role of educating the parents of their young patients with eye problems.
A Child's Eyes provides a quick desk reference for non-ophthalmological practitioners. It covers the multitude of disorders affecting the eyes of children and gives straightforward descriptions of all the common disorders encountered in pediatric ophthalmology. It is an ideal resource that belongs on the bookshelf of every pediatrician and family practitioner. The coverage is concise, yet complete, and the book is well illustrated to support the written descriptions. The excellent index and margin references will bring the subject needing review and the practitioner together in an instant.
Eye problems can be difficult for primary care providers, but they can be completely baffling to parents. When a physician is faced with the need to educate parents, A Child's Eyes will provide the needed information in layman's English.
Both authors are seasoned educators and renowned pediatric ophthalmologists and strabismologists. They have many years of practice in this field, providing care to untold thousands of children and, in the process, investing enormous time interacting with and educating their parents. Although they have addressed this book principally to primary care physicians, it is designed to be shared with interested parents, as well as with educators, occupational therapists, and the many other professionals concerned with children.
A Child's Eyes is a valuable tool for everyone who is interested in acquiring an understanding of this specialty.
Marshall M. Parks, M.D.
PrefaceDuring the course of our careers as pediatric ophthalmologists, we have encountered countless parents who are genuinely perplexed about their children's eye problems. We wrote this book with the realization that, more and more, it will be primary care practitioners who will have to provide answers to their questions. More importantly, these doctors will also be faced with treating certain patients that they previously referred, and will need the confidence to decide when a patient absolutely requires referral. Insurance administrators and others interested in medical care utilization will want to know this information as well.
We've tried to address this book on two levels: first, for primary care physicians, and second, for parents and other nonmedical professionals who have regular contact with our patients. It's not always been easy. There are doubtless some instances when the text will be too elementary for our medical readers and others when it will be too sophisticated for our lay readers. We trust both will be understanding.
Finally, a note about eye doctors. We're both ophthalmologists, which means we completed medical school, one year of post-graduate training in primary medical care, and three years of residency training in ophthalmology – before subspecializing in pediatric ophthalmology. There are also eye doctors of optometry. They have earned a professional degree (O.D.), in a college of optometry. In general, ophthalmologists do optical treatments (glasses and contact lenses), medical management, and surgery for eye problems. Optometrists spend more of their time on optical treatments, and may specialize in such fields as contact lenses and low vision. The differences in scope of practice between ophthalmology and optometry have narrowed in recent years, causing a certain amount of controversy. We want to side-step this controversy, and so have referred to "eye doctor" in many places, specifying "ophthalmologist" only when the issue is clearly surgical.
John W. Simon, M.D.
Joseph H. Calhoun, M.D.
IntroductionLittle Heather was an adorable two-year-old who had her dad – and almost everybody else – wrapped around her little finger. She also had an eye problem.
One day, for no apparent reason, Heather's right eye began to turn inward, or cross. At first Heather's parents weren't sure there really was a problem because her eye crossed only when she was very tired. But gradually the crossing became more pronounced and more frequent. Then it began to happen not only when Heather was tired, but almost all day long. Looking at her picture books made it worse, and she tended to close or cover her right eye.
Her parents began to panic. Her pediatrician referred them to an ophthalmologist, who said that Heather had strabismus. The doctor prescribed a pair of glasses and an eye patch for her left eye. Heather, of course, had no use for either one. Whenever her parents left the room she pulled off the glasses, and the patch came off soon after. Every time, her right eye immediately crossed in again.
Heather's parents were torn. They couldn't stand to see their little girl so uncomfortable. But they were afraid that if they didn't force her to wear the glasses and patch, her vision would be ruined for life. Maybe the doctor had made a mistake. A neighbor said that his son Samuel had once had the same problem as Heather, but a simple operation had corrected it. Surgery sounded awful. But maybe it was better than making Heather do something that made her unhappy and didn't seem to be doing any good.
Heather's story, with minor variations, is repeated every day. Parents are understandably confused and anxious. Eye problems can be complicated, and the technical jargon used to describe them makes them seem even more so. Many parents are afraid that any mistake on their part might damage their children's eyes for the rest of their lives.
It often comes as a surprise to parents that so many different problems can affect how their children see and that so many kinds of treatment may be recommended for problems that, at least at first glance, seem to be identical. When Heather's parents were told that Samuel had had "exactly the same problem" as Heather, the chances are good that the problems weren't really the same at all.
Myths and misconceptions about children's eye problems are widespread. All parents have heard stories about children with "lazy" eyes or "pink" eyes and even such diseases as glaucoma or cataracts. They hear about children who need glasses by age 2 and newborns who need eye surgery. They're convinced that sitting too close to the television or reading with a flashlight under the covers will do permanent damage to their children's eyes.
Parents are surprised to learn:
Before delving into the details of the various problems that can affect
children's eyes, we will begin by explaining the parts of the eye itself.
|THE NORMAL EYE. The transparent cornea reflects a small portion of the incoming light, for example from a camera's flash. That reflection is seen as a white spot at the 10:30 o'clock position in front of the iris and pupil.||THE NORMAL EYE IN CROSS SECTION. The outermost of the three layers includes the transparent cornea and the opaque white sclera. The middle layer is the vascular uvea, made up of the iris, the ciliary body, and the choroid. The innermost layer is the retina.|
PUPILLARY LIGHT REACTION. Both pupils dilate in dim light and constrict in bright light.
The iris and the pupil
Even though it's actually inside the eye, the first part people tend to look at is the iris (plural: irides). The iris is a muscular structure shaped like a doughnut. Its color is determined by pigment cells, which tend to darken during infancy. Generally by 6 to 12 months of age, the color of the iris is determined for life.
The black hole at the center of the iris is the pupil. In darkness it dilates and in light it constricts, due to the involuntary relaxation or contraction of the iris muscles. The pupils also change size in response to looking at things at close range, to different emotional states, and to various kinds of medications and eyedrops.
The optic nerve
Nerve impulses from the photoreceptors in all parts of the retina are passed to the optic nerve, which can be seen inside the eye as a pinkish-yellow disc.
You can "find" your own optic disc by doing a little experiment. Hold your two forefingers in front of you at arm's length. Now close your left eye, concentrate on the tip of the left finger, and move the right finger slowly to the right. When your fingers are about 6 inches apart, the right fingertip will disappear, only to reappear when the fingers are 7 or so inches apart.
You've just demonstrated the "blind spot" caused by the optic disc, which contains no photoreceptor cells. It does contain some one million nerve cells, however, which transmit all of the visual information from the eye to the brain. In fact, anatomists consider the optic nerve a part of the brain.
THE NORMAL OPTIC NERVE AND RETINA. Viewed through the indirect
opthalmoscope, the healthy optic nerve appears as a pinkish-yellow disc. The youthful retina reflects
light as a sheen, which in this picture nearly encircles the macula, partially seen about two and
one-half dissc-diameters to the right of the optic nerve.|