Pediatric Annals

Medical Management of the Child with Subnormal Vision

Andrea Cibis Tongue, MD

Abstract

Medical management of the child with subnormal vision begins at the time of diagnosis and continues for the rest of his or her life. Restoration and maintenance of vision are of paramount concern. Surgery, drugs, optical devices, and amblyopia treatment may be necessary. Equally important is the emotional assistance the physician can give the patient and family. Concerted efforts are necessary to encourage the child to become independent, accept his impairment, and be willing to overcome it.

Treatment of the child involves the family members intimately. Their understanding and action will have the greatest effect on the child's emotional development and ability to cope with his defect. The child's impairment and need for special attention and treatment frequently cause stress within the family, affecting not only the parents but siblings as well. This is particularly true if the child is multiply handicapped. Physicians must be sensitive not only to the child's needs but to the family's as well.

Once the diagnosis is established, the parents should be informed of the extent of visual impairment in understandable and meaningful terms. The disease and the prognosis must be outlined, along with the treatment available. Such terms as "legal blindness" and "20/200 vision" are best avoided. What the family needs and wants to know is whether the child can see toys, recognize faces, ride a tricycle or bicycle, cross streets by himself, learn to read, etc. They and teachers will need information concerning the child's ability to see certain print size, and at what distance, when the child attends school.

As the child gets older, it is essential that he or she understand the cause of visual impairment and prognosis. Teenagers may require advice concerning the feasibility of certain vocational choices. This is especially true if the visual loss is progressive. Efforts should be made to allow the child to become independently mobile. Since many of these children are unable to obtain driver's licenses, they have to depend on parents and friends to drive them. If they live in areas where public transportation is available, they should be encouraged and helped to take advantage of this type of transit. Choice of college may also be influenced by the ease of access of shops, theater, and other activities.

Unfortunately, many of the ocular conditions causing visual impairment in this age group are not curable or correctable. Even if surgery or drug therapy is not feasible, patients and their families should be seen at least once yearly. Many times the statement "There is nothing we can do to correct your child's vision" is taken literally. It is best not to make this type of statement, since there usually are things that can be done to help the child and the family. Many children with subnormal vision have no binocularity and develop strabismus and amblyopia. They should be examined frequently as infants, and amblyopia treatment should be instituted whenever there is a chance to equalize vision.

Refractive errors also occur frequently in this group of patients. Significant retractive errors should be corrected, since they may give the child sharper vision. This is particularly true for the visually impaired high hyperope.

Routine examinations also give the physician a chance to review the child's needs and his as well as the family's and school's ability to deal with them. Occasionally, commonsense suggestions will eliminate problem areas. For example, children with albinism, congenital achromatopia, aniridia, congenital glaucoma, or corneal opacities are extremely light-sensitive. Sunglasses are difficult and expensive to obtain for infants and toddlers. Many of them are helped by wearing a hat with a brim to protect their…

Medical management of the child with subnormal vision begins at the time of diagnosis and continues for the rest of his or her life. Restoration and maintenance of vision are of paramount concern. Surgery, drugs, optical devices, and amblyopia treatment may be necessary. Equally important is the emotional assistance the physician can give the patient and family. Concerted efforts are necessary to encourage the child to become independent, accept his impairment, and be willing to overcome it.

Treatment of the child involves the family members intimately. Their understanding and action will have the greatest effect on the child's emotional development and ability to cope with his defect. The child's impairment and need for special attention and treatment frequently cause stress within the family, affecting not only the parents but siblings as well. This is particularly true if the child is multiply handicapped. Physicians must be sensitive not only to the child's needs but to the family's as well.

Once the diagnosis is established, the parents should be informed of the extent of visual impairment in understandable and meaningful terms. The disease and the prognosis must be outlined, along with the treatment available. Such terms as "legal blindness" and "20/200 vision" are best avoided. What the family needs and wants to know is whether the child can see toys, recognize faces, ride a tricycle or bicycle, cross streets by himself, learn to read, etc. They and teachers will need information concerning the child's ability to see certain print size, and at what distance, when the child attends school.

As the child gets older, it is essential that he or she understand the cause of visual impairment and prognosis. Teenagers may require advice concerning the feasibility of certain vocational choices. This is especially true if the visual loss is progressive. Efforts should be made to allow the child to become independently mobile. Since many of these children are unable to obtain driver's licenses, they have to depend on parents and friends to drive them. If they live in areas where public transportation is available, they should be encouraged and helped to take advantage of this type of transit. Choice of college may also be influenced by the ease of access of shops, theater, and other activities.

Unfortunately, many of the ocular conditions causing visual impairment in this age group are not curable or correctable. Even if surgery or drug therapy is not feasible, patients and their families should be seen at least once yearly. Many times the statement "There is nothing we can do to correct your child's vision" is taken literally. It is best not to make this type of statement, since there usually are things that can be done to help the child and the family. Many children with subnormal vision have no binocularity and develop strabismus and amblyopia. They should be examined frequently as infants, and amblyopia treatment should be instituted whenever there is a chance to equalize vision.

Refractive errors also occur frequently in this group of patients. Significant retractive errors should be corrected, since they may give the child sharper vision. This is particularly true for the visually impaired high hyperope.

Routine examinations also give the physician a chance to review the child's needs and his as well as the family's and school's ability to deal with them. Occasionally, commonsense suggestions will eliminate problem areas. For example, children with albinism, congenital achromatopia, aniridia, congenital glaucoma, or corneal opacities are extremely light-sensitive. Sunglasses are difficult and expensive to obtain for infants and toddlers. Many of them are helped by wearing a hat with a brim to protect their eyes from overhead and direct glare. For older children, a tennis visor, baseball hat, or cap will be acceptable in addition to sunglasses or tinted lenses. When buying school supplies, parents of children with subnormal vision should look for bold-lined paper, rulers with well-contrasted markings, large protractors, etc. As simple and obvious as these solutions may seem, many non-vtsually oriented people never think of them.

Visual aids may also be helpful for the child with subnormal vision. Even though they do not restore normal vision, they allow visualization of objects that could not be seen otherwise. All optical aids work by producing a magnified retinal image. The basic devices are accommodation (ability to decrease the focal distance of the lens), special plus lenses, hand-held and stand magnifiers, telescopes, video projection systems, and large print.

Most preschool or grade-school youngsters use accommodation to help them focus on an object at close range. By bringing the object closer, they increase the retinal image and thus gain magnification. The markedly visually impaired (20/400 or less) or the extremely hyperopic child may not be able to accommodate sufficiently and require an additional lens. The highly myopic child, on the other hand, may do better if he takes his glasses off for near visual tasks. This is often a cause for puzzlement, since glasses are prescribed to improve his vision.

The myopic child who wears his distance correction for near tasks needs to exert the same amount of accommodation as the emmetrope or normal child - and more than if his vision were uncorrected. Highly myopic children may be able to attain up to 10 times magnification at near visual tasks without their glasses Figure 1). Parents and teachers should be informed and reminded that the myopic child with subnormal vision should be allowed and even encouraged to take his glasses off when experiencing difficulty with close work. Many times these youngsters prefer to go without correction as infants or toddlers, since they prefer the ability to view objects clearly at close range.

In my opinion, it is futile to force a small child to accept glasses for visual purposes. If the child sees better with the glasses and appreciates a difference in optical quality, he will wear the glasses. The only time I vigorously encourage parents to enforce the wearing of glasses is for children with vision in one eye only. These children should wear glasses for protective reasons. As the child gets older, the protective lenses can be worn selectively when risk for eye injury is greatest. Wearing of glasses may also need to be enforced when the child is a candidate for strabismus-correction surgery. Glasses may decrease or eliminate esotropia or exotropia in some patients - a factor of vital importance in planning the proper amount of surgical correction.

In general, the device that provides the most useful vision and is the least conspicuous will be the most used by a child. Interestingly, video systems that are bulky and not easily moved are the low-vision aids most readily accepted by schoolchildren and young adults. Most likely this is due to the widespread use of audiovisual equipment in our school systems. Video systems are versatile in that any object can be placed under the camera and instantly replayed on the TV monitor. Magnification up to 45 times can be achieved. Further magnification is obtained when the child moves closer to the screen. These systems can be used for typing, writing, reading, etc. The biggest disadvantages are cost and bulk.

Figure 1. Child with -14.00 myopia utilizing accommodation and uncorrected myopia to read book. Distance acuity, corrected, is 20/400. Near vision is 20/40 equivalent at 2 inches from eye. Child has also spontaneously learned the additional benefit of creating a pinhole with his fingers.

Figure 1. Child with -14.00 myopia utilizing accommodation and uncorrected myopia to read book. Distance acuity, corrected, is 20/400. Near vision is 20/40 equivalent at 2 inches from eye. Child has also spontaneously learned the additional benefit of creating a pinhole with his fingers.

Spectacles or magnifiers are portable and can be used anyplace. However, spectacles have the disadvantage of short focal distances. Many teenagers and adults are extremely self-conscious about having to read at a very close range. Furthermore, many will not wear thick lenses in class. Small magnifiers may be more acceptable. Figure 2 shows several low-vision aids. Older patients with senile macular degeneration almost always prefer the larger magnifiers with handles. Teenagers usually choose the small folding pocket magnifier or the stand magnifier. Small children like the stand. Physicians need to understand and be willing to find a low-vision aid that is acceptable to the child while trying to encourage him to overcome his self-consciousness.

It is for the latter reason that I like to prescribe visual aids for children before they go to school. They are much less self-conscious and willing to adapt at this age than they are during the teen or adult years. Aids also allow them and their parents to experience what magnification can do. The need for large-print books is often circumvented by the use of reading glasses, bifocals, or a magnifier.

Distance telescopes are particularly appreciated by the visually impaired child. The child shown in Figure 3 wears his telescope on a string so that it is available at all times. His mother reported that when he first got it he ran from window to window in their house and described with glee all he could now see outside. Many older children take their telescopes to school, and adults use them for viewing bus numbers, street signs, aisle markers in grocery stores, etc. More sophisticated spectaclemounted telescopes are available but are of very limited use in children because of their appearance and weight. Since telescopes severely restrict the visual field, they are obviously of limited use for walking, driving, etc. and are used predominantly for sighting.

It is important to remember that visual aids are static devices with a limited focal range. Some children, particularly those with aphakia, may need several devices for different visual tasks. Occasionally, such non-optical aids as adjustable music stands, which can be brought close to the child, talking calculators, and self-threading sewingmachine needles allow the child to function without a special optical aid. Illumination adjustments are also often helpful. Depending on the basic disorder, vision may be helped or hindered by bright illumination. Children with retinal dysfunction, albinism, corneal opacities, or cataracts may perform better in dim light. Unfortunately, all too often, wellmeaning adults will seat them under the brightest fluorescent light in the room. Usually the child knows best, and he should be asked about his lighting preference.

It is beyond the scope of this article to outline specific surgical procedures or drug therapies, since use of these depends on the basic defect. Children who require surgery for restoration or maintenance of vision are often subject to more than one operation. Many become hospital veterans at an early age. Every effort should be made to make their hospital stays as short and pleasant as possible. And advances in instrumentation, suture material, and surgical techniques have decreased postoperative complications of many eye operations, allowing the patient (and family) to resume normal activity much sooner.

Drug treatment in children is problematic because of poor compliance. Children with glaucoma, for example, may require drops for years. Efforts should be made to prescribe drugs with prolonged action when possible. Directions as to the time of administration must be specific. Drops meant to be given every six hours but ordered q.i.d. may be given by the parent at four convenient times of the day - i.e., before school (7 A.M.), after school (3 P.M.), before dinner (6 P.M.), and at bedtime (8 P.M.). Many schools do not have nurses, and special arrangements may be necessary for drug administration by teachers or other personnel. In some cases, the parent may have to go to school to administer the drops.

Figure 2. Various optical aids, including hand-held, fixedfocus stand magnifiers, folding pocket magnifier, clip-on jeweler's loupe, and distance monocular telescope.

Figure 2. Various optical aids, including hand-held, fixedfocus stand magnifiers, folding pocket magnifier, clip-on jeweler's loupe, and distance monocular telescope.

Parents should be warned about the potential lethal effects of eye drops or other eye medication. The least amount possible should be carried by the child to school, and bottles or containers should be marked to identify the contents. Parents often do not consider the possible toxicity of the drug their child is taking routinely. One of my nine-year-old glaucoma patients took a bottle of 100 Diamox pills to school to keep in her desk! Her mother had never considered the possibility that another child might take them.

Figure 3, Child with monocular distance telescope of 8x power.

Figure 3, Child with monocular distance telescope of 8x power.

Figure 4. Child with bilateral microphthalmos. Right eye is markedly affected, with ptosis and smaller horizontal palpebral fissure.

Figure 4. Child with bilateral microphthalmos. Right eye is markedly affected, with ptosis and smaller horizontal palpebral fissure.

Figure 5. Same child as in Figure 4 after prosthesis has been inserted. Glasses were prescribed for protection of the only seeing eye.

Figure 5. Same child as in Figure 4 after prosthesis has been inserted. Glasses were prescribed for protection of the only seeing eye.

The importance of correcting cosmetic defects whenever possible cannot be overemphasized. This is true even if the child is totally blind. Initially the child is oblivious to his defects; parents and other adults are not. Well-meaning or curious strangers may come up to the parents in grocery stores and ask them what is wrong with the child, whether something can be done about it, whether they have taken the child to the doctor, etc. Later, the child is subject to peer ridicule and, often, cruelty. It is important that family and teacher support the child and assist him in dealing with this problem.

Figure 6. Child with bilateral retinoblastoma and enucleation of left eye. Normal appearance with prosthesis.

Figure 6. Child with bilateral retinoblastoma and enucleation of left eye. Normal appearance with prosthesis.

Figure 4 shows a child with bilateral microphthalmos secondary to dominantly inherited mesodermal dysgenesis. His right eye was blind and much smaller than the left. He was unable to elevate the lid because of the decreased volume of the globe. Figure 5 shows the same child after he was fitted with a prosthetic shell. His pleasure is obvious.

The child in Figure 6 had enucleation of the left eye for advanced retinoblastoma. Unfortunately, the right eye also had a large tumor in the macular area. She is wearing a prosthetic eye, which allows her to appear totally normal. Regrettably, thirdparty carriers in some instances still refuse to pay for ocular prostheseis and consider them purely cosmetic. One of my patients was recently denied payment for a prosthesis by a state agency because the physician reviewer believed that a child that age would not wear a prosthesis anyway.

Prostheses in case of anophthalmos or marked microphthalmos are necessary in the young for optimal orbital growth as well as for psychologic benefit. Congenital anophthalmos should be treated during the first few weeks of life. Increasing-size plastic conformers are placed in the empty socket to mechanically stretch the tissues. This type of treatment may need to be carried out for many months until the optimal-size prosthesis can be inserted. During the first years of life, artificial eyes need to be enlarged or changed every one to two years to keep up with the child's growth.

Finally, I would like to emphasize the need for early diagnosis of the child's visual disorder. Many times, early detection is essential for restoration or maintenance of sight. This is particularly true for infantile-glaucoma patients and patients with retinoblastoma. However, the eye disease may often be the first manifestation of other disorders. Furthermore, many of the disorders causing subnormal vision in childhood are genetic. Family studies are imperative, as are examinations of parents and siblings. Dominantly inherited disorders may have variable penetrance and expressivity and therefore be unrecognized in some persons. Carriers of X-linked disorders may have minor but readily identifiable abnormalities.

Obviously, genetic disorders cannot be ruled out by the absence of disease in other family members, since autosomal-recessive disorders are usually never manifest in previous generations. X* linked disorders may not be manifest for generations either. New germinal mutations producing dominantly inherited conditions will not affect preceding generations but will affect subsequent ones. In my experience, this has been particularly true for congenital cataracts, retinoblastoma, and aniridia. It is not unusual to see children with congenital cataracts whose affected parent was told that his or her cataracts would not be passed on since "they were due to rubella."

Many retinoblastoma patients do not know the statistical risk for passing the gene to their offspring. This is especially true for unilateral-retinoblastoma victims. Retinoblastoma is a dominantly inherited disease with variable penetrance. The risk for recurrence in case of bilaterally affected patients is approximately 10 percent for their siblings and 40 to 50 percent for their children. In case of unilateral retinoblastoma, the risk for affected offspring is much less. No matter how small the risk, however, the potentially affected child should be examined for the disease from the time of birth. Small tumors can often be eradicated by photocoagulation, laser, or cryotherapy. Larger lesions require irradiation or enucleation and decrease the life expectancy. In the past year I have treated offspring of two unilateraJ-retmoblastoma patients. Both children had bilateral tumors detected at a few months of age.

Bilateral-retinoblastoma patients are also at risk for developing other cancers. In most cases these are fatal.

Many young adults with genetically determinedeye diseases have no idea how the disease is inherited or how it may or may not be passed on. This information should be made available to them so that they can make an informed decision regarding reproduction. It is equally important that they understand the prognosis for vision, since a number of diseases - such as retinitis pigmentosa, cone-rod dystrophy, and aniridia - may lead to markedly impaired vision or blindness later in life.

CONCLUSION

Only a few aspects of medical care of the visually impaired have been discussed. Emphasis was placed on the need for continuing care even for those children and adults who have stationary or noncurable diseases. The pediatrician and the ophthalmologist must make a concerted effort to inform first the parents and then the child of his or her visual impairment and prognosis. This must be done in terms easily understood by the patient. Optical aids are often helpful in maximizing vision. The preponderance of generic disorders in this group of children is important to keep in mind.

GENERAL REFERENCES

Aids and Appliances for the Blind and Visually Impaired, 26th Edition. New York: American Foundation for the Hind (catalogue). 1980.

Corn, A., and Martinez, I. When You Haoe a Visually Handicapped Child in Your Classroom: Suggestions for Teachers. New York: American Foundation for the Hind (pamphlet), 1977. Goldberg, M. F. (ed.): Genetic and Metabolic Eye Disease. Boston: Little, Brown and Company, 1974.

Harley, R. D. (ed.): Pediatrie Ophthalmology. Philadelphia: W. B. Saunders Company, 1975.

10.3928/0090-4481-19801101-08

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