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A Technique for Visual Appraisal of Mentally Retarded Children
A T E C H N I Q U E FOR VISUAL A P P R A I S A L O F MENTALLY RETARDED CHILDREN LAWRENCE J. LAWSON, JR., M.D.,
AND GREG SCHOOFS,
M.D.
Evanston, Illinois
Because of their intellectual handicap, it is of utmost importance that visual deficiencies of retarded children be recognized and cor rected to provide maximum potential for learning. Unfortunately, many of these chil dren have never had a visual examination; further, if one is performed, reliable data may be difficult to obtain. The child may be difficult to deal with, and frequently the oph thalmologist does not have a satisfactory method of examination in this situation. In working with a group of children with men tal handicaps, we developed a practical sys tem for their visual evaluation which we have described in this paper. METHODS
A group of 103 day students was exam ined from the Orchard School for mentally handicapped children in Skokie, Illinois. These students, whose mental retardation re sulted from various causes (Table 1), ranged in age from three to 22 years; each child's intelligence quotient was 60 or less. The school nurse devised a routine for fa miliarizing the students with the general pro cedure to be used in the examination. This resulted in a definite reduction of apprehen sion and permitted the children to be more cooperative, thus allowing a more thorough and accurate appraisal. The tests were per formed in the Eye Clinic of Evanston Hos pital at a time when other activities were not scheduled in order to provide a quieter and less disturbing environment. Each child was examined alone, with the nurse from the school in attendance for identification and reassurance. Because these children generFrom the Departments of Ophthalmology of Ev anston Hospital and of Northwestern University Medical School. This work was supported by a grant from the Ben Levin Memorial for Retarded Children. Reprint requests to Lawrence J. Lawson, Jr., M.D., 636 Church Street, Evanston, Illinois 60201.
TABLE 1 CAUSES OF MENTAL RETARDATION Down's syndrome Unknown Brain damage Non-verbal 9 Verbal 4 Cerebral palsy Cerebral dysgenesis Postencephalitis Rh factor Cerebral ataxia Cranial dysostosis Microcephalos "Battered child" syndrome Total
33 29 13 11 3 4 3 3 2 1 1 103
ally have a short attention span and are eas ily distracted, the test procedures were per formed rapidly. When a test proved beyond the comprehension of a child, it was elimi nated and the next procedure presented. The initial approach was a general ap praisal of the eyes and adnexa. Visual acuity was then recorded. Lippmann 1 has stated that young children do not have the concept of direction and therefore the illiterate " E " is usually unreliable. He also reported that these children require identification of one symbol at a time. These statements were confirmed in our study. "Pictographs" utiliz ing symbols familiar to children, as, devised by Allen,2 were attempted, but these children were unable to recognize these symbols and so another method was developed. We at tempted the use of the Stycar test,3-* which employs cut-out symbols placed on a table to be matched with similar objects at a distance. This system did not prove successful because children with mental retardation frequently do not comprehend the concept of "likeness" or similarity. Since most of the children could recognize food items (and often no others), selected items from the Peabody series5 were photo-
622
VOL. 72, NO. 3
623
VISUAL APPRAISAL OF RETARDATES
graphed in color to provide a series of 2 X 2 slides to be used with a projector. Because of the resolution of the projected picture, smaller symbols could not be satisfactorily reproduced. We therefore designed a wall chart printed in color using the food items, (apple, banana, "hot dog," and ice cream cone) calibrated for the standard 20-foot distance.* Each symbol can be framed by an * The chart used in this study may be ordered as "Apple Chart" from Medical Contact Lens Service, 1225 Circle Tower, Indianapolis, Indiana 46204.
TABLE 2 METHODS OF DETERMINING VISION
Technique
No. Children
Snellen " E " game Food pictures Could not test
27 14 36 26
adjustable framer to stimulate attention. This method proved successful in a high per centage of cases. (Fig. 1) Ocular muscle coordination and the fusion status were then ascertained when possible, utilizing the Worth 4-dot, the Maddox rod and the Wirt Stereotest. Prism cover tests were also used. All of the children had retinoscopy performed under cyclopegia. The use of the refractor or trial frame was gen erally too frightening to the child. There fore, either the loose lenses or the Foster retinoscopy rack was used; these methods were preferred because of their rapidity, and a fairly accurate measurement was possible in the majority of cases. The ocular fundi were examined for defects by indirect ophthalmoscopy, which proved to be vastly superior to the direct method because it enabled us to perform the examination without touching the child. RESULTS
Fig. 1 (Lawson and Schoofs). Wall chart, printed in color and calibrated for the standard 20-foot dis tance, devised to test mentally retarded children.
With the system described above, we were able to determine the visual acuity of a sig nificant number of this group of mentally re tarded children. (Table 2) Unfortunately, there remain some children for whom no system yet devised is satisfactory. In our se ries there were 18 children who initially had less than 20/70 uncorrected vision in their better eye (sight-saving cut-off level), 15 of whom could be corrected to better acuity. These children had not previously been iden tified as having visual problems. Only 28% of our children were considered to be ophthalmologically normal, whereas in a general school population approximately 75% are usually found to be without visual motor or sensory difficulties. A total of 44 children had significant re-
624
AMERICAN JOURNAL OF OPHTHALMOLOGY TABLE 3
SUMMARY
T Y P E S OF REFRACTIVE ERRORS
Condition
S E P T E M B E R , 1971
No. Eyes
Hyperopia 1.00-2.00 diopters 2.25-4.75 diopters Over 5 diopters
6 24 9
Myopia 1.00-2.00 diopters 2.25-4.75 diopters Over 5 diopters
6 6 5
Astigmatism 1.00-2.00 diopters 2.25-4.75 diopters Over 5 diopters
9 21 2
Total
88
tractive errors (Table 3). In 25 of these the visual defects were unknown to the school or to the parents, and required corrective lenses. There were 19 children who were al ready wearing glasses, nine of whom needed significant changes in the power of their spectacles. There were 33 of the 103 children who had some degree of ocular muscle imbalance (Table 4). This incidence is almost 10 times that of a normal population of this age group. There were nine students with an am blyopic eye who had never received treat ment, and the majority of the parents had no previous knowledge of the condition. There were 18 with definite esotropia and four with significant esophoria. Six children had a constant exotropia, and four had an inter mittent exotropia. Two children had had previous eye surgery. CONCLUSIONS
The results of our study demonstrate the need for an ophthalmic appraisal of the men tally retarded child. These children have a high incidence of visual defects which may influence their level of functioning, espe cially in a learning situation. The need for treatment of a visual defect must be individ ually determined and the school alerted to the special problems and visual needs of the child.
A group of 103 mentally retarded children varying in age from three to 22 years were examined for visual difficulties. Because of the inability to determine the visual acuity in many of these children by any available tech nique, a chart was designed utilizing food items printed in color and calibrated for the standard 20-foot distance. By this method, a substantial number of children can be added to those in whom the visual acuity can be de termined. Only 28% of our children were considered ophthalmologically normal as contrasted to the approximately 75% in a normal school population. Among other ocu lar findings, 44 had significant refractive er rors, 33 children were found to have ocular muscle imbalance, and there were nine stu dents with an amblyopic eye. ACKNOWLEDGMENTS
W e thank Julia S. Molloy, Director of the Molloy Education Center, and Mrs. Peg Miller, R.N., for their invaluable assistance in this project. REFERENCES
1. Lippmann, O.: Vision of young children. Arch Ophth. 81:763, 1969. 2. Allen, H. F . : A new picture series for pre school vision testing. Am. J. Ophth. 44:38, 1957. 3. Sheridan, M.: Vision screening of very young or handicapped children. Brit. Med. J. 2:453, 1960. 4. Sheridan, M . : Stycar tests. Brit. Orthop. J. 20:32, 1963. 5. Dunn, L. M., and Smith, J. O . : Peabody Lan guage Development Kit. Circle Pines, Minnesota, American Guidance Service, 1965. TABLE 4 MISCELLANEOUS VISUAL FINDINGS
Nystagmus Partial blepharoptosis Marginal blepharitis Microphthalmos Iris atrophy Brushfield spots of iris Corectopia Zonular cataract Posterior lenticonus Cataracts Retinopathy Medullated nerve Optic atrophy Hemianopsia
fibers
10 2 20 1 1 18 1 1 1 2 1 1 1 1
AND GREG SCHOOFS,
M.D.
Evanston, Illinois
Because of their intellectual handicap, it is of utmost importance that visual deficiencies of retarded children be recognized and cor rected to provide maximum potential for learning. Unfortunately, many of these chil dren have never had a visual examination; further, if one is performed, reliable data may be difficult to obtain. The child may be difficult to deal with, and frequently the oph thalmologist does not have a satisfactory method of examination in this situation. In working with a group of children with men tal handicaps, we developed a practical sys tem for their visual evaluation which we have described in this paper. METHODS
A group of 103 day students was exam ined from the Orchard School for mentally handicapped children in Skokie, Illinois. These students, whose mental retardation re sulted from various causes (Table 1), ranged in age from three to 22 years; each child's intelligence quotient was 60 or less. The school nurse devised a routine for fa miliarizing the students with the general pro cedure to be used in the examination. This resulted in a definite reduction of apprehen sion and permitted the children to be more cooperative, thus allowing a more thorough and accurate appraisal. The tests were per formed in the Eye Clinic of Evanston Hos pital at a time when other activities were not scheduled in order to provide a quieter and less disturbing environment. Each child was examined alone, with the nurse from the school in attendance for identification and reassurance. Because these children generFrom the Departments of Ophthalmology of Ev anston Hospital and of Northwestern University Medical School. This work was supported by a grant from the Ben Levin Memorial for Retarded Children. Reprint requests to Lawrence J. Lawson, Jr., M.D., 636 Church Street, Evanston, Illinois 60201.
TABLE 1 CAUSES OF MENTAL RETARDATION Down's syndrome Unknown Brain damage Non-verbal 9 Verbal 4 Cerebral palsy Cerebral dysgenesis Postencephalitis Rh factor Cerebral ataxia Cranial dysostosis Microcephalos "Battered child" syndrome Total
33 29 13 11 3 4 3 3 2 1 1 103
ally have a short attention span and are eas ily distracted, the test procedures were per formed rapidly. When a test proved beyond the comprehension of a child, it was elimi nated and the next procedure presented. The initial approach was a general ap praisal of the eyes and adnexa. Visual acuity was then recorded. Lippmann 1 has stated that young children do not have the concept of direction and therefore the illiterate " E " is usually unreliable. He also reported that these children require identification of one symbol at a time. These statements were confirmed in our study. "Pictographs" utiliz ing symbols familiar to children, as, devised by Allen,2 were attempted, but these children were unable to recognize these symbols and so another method was developed. We at tempted the use of the Stycar test,3-* which employs cut-out symbols placed on a table to be matched with similar objects at a distance. This system did not prove successful because children with mental retardation frequently do not comprehend the concept of "likeness" or similarity. Since most of the children could recognize food items (and often no others), selected items from the Peabody series5 were photo-
622
VOL. 72, NO. 3
623
VISUAL APPRAISAL OF RETARDATES
graphed in color to provide a series of 2 X 2 slides to be used with a projector. Because of the resolution of the projected picture, smaller symbols could not be satisfactorily reproduced. We therefore designed a wall chart printed in color using the food items, (apple, banana, "hot dog," and ice cream cone) calibrated for the standard 20-foot distance.* Each symbol can be framed by an * The chart used in this study may be ordered as "Apple Chart" from Medical Contact Lens Service, 1225 Circle Tower, Indianapolis, Indiana 46204.
TABLE 2 METHODS OF DETERMINING VISION
Technique
No. Children
Snellen " E " game Food pictures Could not test
27 14 36 26
adjustable framer to stimulate attention. This method proved successful in a high per centage of cases. (Fig. 1) Ocular muscle coordination and the fusion status were then ascertained when possible, utilizing the Worth 4-dot, the Maddox rod and the Wirt Stereotest. Prism cover tests were also used. All of the children had retinoscopy performed under cyclopegia. The use of the refractor or trial frame was gen erally too frightening to the child. There fore, either the loose lenses or the Foster retinoscopy rack was used; these methods were preferred because of their rapidity, and a fairly accurate measurement was possible in the majority of cases. The ocular fundi were examined for defects by indirect ophthalmoscopy, which proved to be vastly superior to the direct method because it enabled us to perform the examination without touching the child. RESULTS
Fig. 1 (Lawson and Schoofs). Wall chart, printed in color and calibrated for the standard 20-foot dis tance, devised to test mentally retarded children.
With the system described above, we were able to determine the visual acuity of a sig nificant number of this group of mentally re tarded children. (Table 2) Unfortunately, there remain some children for whom no system yet devised is satisfactory. In our se ries there were 18 children who initially had less than 20/70 uncorrected vision in their better eye (sight-saving cut-off level), 15 of whom could be corrected to better acuity. These children had not previously been iden tified as having visual problems. Only 28% of our children were considered to be ophthalmologically normal, whereas in a general school population approximately 75% are usually found to be without visual motor or sensory difficulties. A total of 44 children had significant re-
624
AMERICAN JOURNAL OF OPHTHALMOLOGY TABLE 3
SUMMARY
T Y P E S OF REFRACTIVE ERRORS
Condition
S E P T E M B E R , 1971
No. Eyes
Hyperopia 1.00-2.00 diopters 2.25-4.75 diopters Over 5 diopters
6 24 9
Myopia 1.00-2.00 diopters 2.25-4.75 diopters Over 5 diopters
6 6 5
Astigmatism 1.00-2.00 diopters 2.25-4.75 diopters Over 5 diopters
9 21 2
Total
88
tractive errors (Table 3). In 25 of these the visual defects were unknown to the school or to the parents, and required corrective lenses. There were 19 children who were al ready wearing glasses, nine of whom needed significant changes in the power of their spectacles. There were 33 of the 103 children who had some degree of ocular muscle imbalance (Table 4). This incidence is almost 10 times that of a normal population of this age group. There were nine students with an am blyopic eye who had never received treat ment, and the majority of the parents had no previous knowledge of the condition. There were 18 with definite esotropia and four with significant esophoria. Six children had a constant exotropia, and four had an inter mittent exotropia. Two children had had previous eye surgery. CONCLUSIONS
The results of our study demonstrate the need for an ophthalmic appraisal of the men tally retarded child. These children have a high incidence of visual defects which may influence their level of functioning, espe cially in a learning situation. The need for treatment of a visual defect must be individ ually determined and the school alerted to the special problems and visual needs of the child.
A group of 103 mentally retarded children varying in age from three to 22 years were examined for visual difficulties. Because of the inability to determine the visual acuity in many of these children by any available tech nique, a chart was designed utilizing food items printed in color and calibrated for the standard 20-foot distance. By this method, a substantial number of children can be added to those in whom the visual acuity can be de termined. Only 28% of our children were considered ophthalmologically normal as contrasted to the approximately 75% in a normal school population. Among other ocu lar findings, 44 had significant refractive er rors, 33 children were found to have ocular muscle imbalance, and there were nine stu dents with an amblyopic eye. ACKNOWLEDGMENTS
W e thank Julia S. Molloy, Director of the Molloy Education Center, and Mrs. Peg Miller, R.N., for their invaluable assistance in this project. REFERENCES
1. Lippmann, O.: Vision of young children. Arch Ophth. 81:763, 1969. 2. Allen, H. F . : A new picture series for pre school vision testing. Am. J. Ophth. 44:38, 1957. 3. Sheridan, M.: Vision screening of very young or handicapped children. Brit. Med. J. 2:453, 1960. 4. Sheridan, M . : Stycar tests. Brit. Orthop. J. 20:32, 1963. 5. Dunn, L. M., and Smith, J. O . : Peabody Lan guage Development Kit. Circle Pines, Minnesota, American Guidance Service, 1965. TABLE 4 MISCELLANEOUS VISUAL FINDINGS
Nystagmus Partial blepharoptosis Marginal blepharitis Microphthalmos Iris atrophy Brushfield spots of iris Corectopia Zonular cataract Posterior lenticonus Cataracts Retinopathy Medullated nerve Optic atrophy Hemianopsia
fibers
10 2 20 1 1 18 1 1 1 2 1 1 1 1