The Pediatric Low-Vision Patient

The Pediatric Low-Vision Patient

Anne Frances Walonker

T he American Academy of Pediatrics states that 75% of learning during the early years is processed through vision;

because vision is a learning sense, children with visual impair- ment may not learn to perform many tasks as quickly as those with normal vision. Children with subnormal vision often look and act like any other child in the classroom and on the play- ground making it difficult to distinguish them from normally sighted children. Children with low vision may wear thick glasses or even dark glasses, but they will run and jump as fear- lessly as their playmates.

Never having known any other vision, these children are often unaware that their vision is less than that of other chil- dren, and the majority adapt quite well to their environment.

Only a few children with low vision need special schools or a protected environment. The majority of these low-vision chil- dren function much better in a standard school system with the help of a resource teacher for some part of the school week. As much as is possible, these children need to be mainstreamed.

They need to be expected to perform the same tasks and to assume the same responsibilities as normally sighted children of the same age.

INCIDENCE

According to the Centers for Disease Control (CDC), nearly 1 in 1000 children in the United States has some degree of low vision or is legally blind.

Not being able to see can alter how a child understands and functions in the world. Impaired vision can

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affect a child’s emotional, neurological, and physical develop- ment by potentially limiting the range of experiences and the kinds of information to which a child is exposed.

CLINICAL FEATURES

Decreased vision in a child can be caused by many different processes, each one requiring a different method of treatment:

either medical, surgical, or optical. If normal vision cannot be restored, then the use of both optical and nonoptical aids to enhance the remaining vision is necessary.

Whatever the cause of the decreased vision, early interven- tion is of the utmost importance for the child to adapt to the environment and to continue the learning processes without interruption. The clinical features that could alert a parent to signs of a visual problem in their child include, but are not limited to, nystagmus, strabismus, random eye movements, leukocoria, and corneal opacity.

CLINICAL ASSESSMENT

Clinical assessment of a child with a suspected visual impair- ment always consists of a very detailed clinical evaluation by a pediatric ophthalmologist, with ancillary testing such as elec- trophysiology and ultrasonography when appropriate.

The measurement of visual function should be done with targets appropriately sized for both the age of the child and the level of vision suspected, moving the child closer to the testing targets both for near and for distance. The visual requirements for each child should also be assessed because the various ther- apeutic modalities are age and task appropriate.

The importance of early diagnosis of the child’s visual disability cannot be overstated. The earlier the disability is diagnosed, the earlier treatment intervention can begin. Early treatment may produce a better outcome by allowing a stepwise approach to planning the use of aids, both visual and nonvisual, for the short and long term. For those children with an inher- ited process, early diagnosis makes it possible to provide expe- dient and appropriate counseling for the families involved.

Innumerable low-vision aids of various types are available for

enhancing both distance and near vision. The type of device that

is appropriate will change as the child becomes older and their visual requirements change and increase. The low-vision devices that are useful for children bear no relationship to those used by most adults.

Because reading is the child’s access to learning, a visual aid that makes this task possible is one of the most important devices for these children. The phakic school-age child has an enormous range of accommodation. These children find that reading can be a simple matter of bringing the print close enough to their faces to magnify the image. A fixed-stand low-power magnifier (Fig. 3-1) to enhance these images is probably the most useful low-vision aid for these young children. When the mag- nifier is placed directly on the page, its fixed focus keeps the

FIGURE 3-1. Low-power stand magnifier.

print clear at all times and lets the child run the device along the page. Even very young children learn to manipulate these devices, and they have been found more useful than many of the more technically sophisticated and costly aids available today.

The aphakic child has different needs. However, glasses or contact lenses with reading additions and the same fixed-focus stand magnifiers can be of great help to these children. The other aid that is exciting to young children with decreased vision is a monocular telescope (Fig. 3-2). It takes a little longer to master this device, but, once the child learns to use it, it opens up a whole new world. The small size of these telescopes makes

FIGURE 3-2. Monocular telescope.

them highly portable. A child can use this device anywhere and can share it with normally sighted friends, thus erasing the stigma associated with the use of a low-vision aid.

The social and academic success of a child with a visual dis- ability depends largely on the expectations of the family and the understanding of the teachers and the school administrators; the focus should not be on the limitations that the visual disability creates but on the heights that these children can achieve.

Teachers, classroom aides, and playground supervisors should be encouraged to treat these children no differently than they treat the others in the class. However, staff need to remain aware of the children’s special needs and address these needs appropri- ately. Where these children are seated in the classroom, the dis- tance between them and the blackboard, the size of the letters on the board, the color of the chalk used, and the angle of the glare from the windows are all as important as any optical or nonoptical visual aid being used.

Furnishing the family and the teachers with a detailed report of the size of print that the child can see for both near and dis- tance work is most helpful. When there are problems with con- trast on homework assignments (some copies are so poor that enlarging the print makes them impossible to read), a different type of copy for these children is important. For some children, a closed-circuit television (Fig. 3-3) facilitates reading when increased magnification is required, as the magnifying glass of increased power decreases the field of view. These devices are expensive, but an older child will find them very useful. Most schools with resource centers make them available, as do public libraries.

With increased awareness of and attention to those things that make schoolwork easier to handle, most children will adapt well to their less-than-normal vision, which will do more for their self-confidence than any expensive magnifier or compli- cated reading machine can possibly do. However, as the child becomes older and reading demands increase, these more sophis- ticated instruments will become appropriate and should be added to the armamentarium. Newer instruments include closed-circuit television cameras that can be used with com- puters and portable handheld devices that scan curved surfaces and have large-print readouts on the handles. There are many headborne devices, used for both distance and near reading, that are appropriate for adults who need them to maintain a career.

These newer devices are not really necessary in the elementary

and high school classroom, but they may be more useful to college students who sit in large classrooms and who may find it necessary to copy notes from distant blackboards or screens.

There are some points to remember when evaluating a child for visual aids:

• Amblyopia can occur in the presence of another visual abnormality and should be treated vigorously. The better the vision, the less magnifying power needed.

• It is acceptable for moderate to high myopes to remove their glasses for near work.

• The accommodative range will decrease as these children get older, and a change in vision does not necessarily mean a worsening of a previously stable condition.

• There is no limit to the amount of reading aid that can be prescribed so long as this aid improves near vision.

• Only those visual aids that are needed for the currently per- formed tasks should be prescribed. For the young child, this will probably mean a stand magnifier for near tasks and a telescope for distance tasks.

FIGURE 3-3. Closed-circuit television.

RESOURCES

Bibliography from Pediatric Ophthalmology Consumer Resources

Madelyn Hall

Good Samaritan Hospital and Medical Center 1040 N.W. 22nd Avenue

Portland, OR 97219

“Vision and Vision Impairment” (a bibliography of books for children)

Pediatric Projects Incorporated P.O. Box 1880

Santa Monica, CA 90406

“Selected readings for parents of preschool handicapped children”

National Library Service for the Blind and Physically Handicapped

Library of Congress 1291 Taylor Street NW Washington DC 20542 1-800-424-8567

Additional Resources

National Association for the Visually Handicapped (NAVH) 305 East 24th Street

New York, NY 10010

American Foundation for the Blind Customer Service Division 15 West 16th Street New York, NY 10010

Reference

1. Centers for Disease Control. NECH Publ no 99-0444. National Center for Environmental Health, Centers for Disease Control.

Washington, DC: 1999.