Journal of Pediatric Ophthalmology and Strabismus

Accommodation in School Children With Music or Sports Activities

Maija I Mäntyjärvi, MD

Abstract

ABSTRACT

The accommodation of 324 school children aged 10 to 16 years was studied before and after a 12-minute reading session. One hundred and twenty children (81 girls and 39 boys) were wind instrument players in school bands, 93 children (48 girls and 45 boys) trained in an individual sport, and 111 children (65 girls and 46 boys) having no such activities were studied as a control group. At the end of the reading session, decreased accommodation (7 diopters or less) was found in 19 (15.8%) of the musicians, in six (6.5%) of the athletes, and in six (5.4%) of the control group. The difference was significant between the musicians and the control group, but not significant between the athletes and the control group. The majority of the children with low accommodation were girls; there was only one boy with decreased accommodation in each of the three groups.

Abstract

ABSTRACT

The accommodation of 324 school children aged 10 to 16 years was studied before and after a 12-minute reading session. One hundred and twenty children (81 girls and 39 boys) were wind instrument players in school bands, 93 children (48 girls and 45 boys) trained in an individual sport, and 111 children (65 girls and 46 boys) having no such activities were studied as a control group. At the end of the reading session, decreased accommodation (7 diopters or less) was found in 19 (15.8%) of the musicians, in six (6.5%) of the athletes, and in six (5.4%) of the control group. The difference was significant between the musicians and the control group, but not significant between the athletes and the control group. The majority of the children with low accommodation were girls; there was only one boy with decreased accommodation in each of the three groups.

INTRODUCTION

The accommodation of school children usually is considered very good, 10 to 15 diopters (D).1 However, the author, a school ophthalmologist, often finds the accommodative capacity of school children to be distinctly below the agerelated normal level.2 Usually these children complain of headaches or blurring of vision in reading or other near tasks and are sent for eye examination. Over 10 years, two prominent groups of children such as these have been observed. One group consists of children who play a wind instrument in the school band; the other group consists of children who are training for an individual sport, most often track and field or swimming. The children coming to the eye examinations are a select group, however, and we do not know if the accommodation really is decreased more often in children with sport or wind instrument playing activities than in other children. The purpose of this study was to find out if the accommodation in randomly selected groups of school children training in individual sports or playing in school bands is lower than in children with no such activities.

SUBJECTS AND METHODS

From the schools of Kuopio, Finland (population 76,000, with approximately 10,000 school children 7 to 16 years of age), eight randomly-selected classes were invited to participate in the study.

Four classes were music classes where all of the children play a wind instrument in the school band. These children had begun the music class program starting in the third grade, at the age of 9 years. Playing a wind instrument is a school subject until the sixth grade. Four classes were regular school classes with no extra training connected with the school. The children training actively in sports were randomly selected from the local track and field sports society and from the local swimming society, both of which compete in local or national championship tournaments. The children had been training in the wind instrument or sport for at least 1 year before the study began.

A total of 340 children aged 10 to 16 years were asked to participate in the study. Thirteen children did not come to the examination. Three children were training both to play a wind instrument and in competitive individual sports; thus, their examination results were not used. Altogether 324 children participated in the study: 120 children (mean age 12.1 years ± 1.7, SD; 81 girls, 39 boys) played a wind instrument, 93 children (mean age 12.7 ± 1.8; 48 girls, 45 boys) trained in sports (44 in track and field and 49 in swimming), and Ul children (mean age 12.1 ± 1.5; 65 girls and 46 boys) had no such activities. The music classes had a majority of girls, and in the sports societies the mean age was higher than in the music classes; this explains the greater number of girls and the slight age differences in the groups. None of the children in the three study groups had any disease or were taking any medications that could have affected their accommodation.

Table

TABLE 1Distribution of Age and Sex of Children With Decreased Accommodation

TABLE 1

Distribution of Age and Sex of Children With Decreased Accommodation

The eye examination consisted of testing the vision, phorias, and refraction (without cycloplegy), as well as biomicroscopy and ophthalmoscopy. No eye drops were used during the examination, to encourage as many children as possible to participate in the study. The accommodation was measured monocularly (right eye with corrected refraction) with the push-up method (near point rule, Clement Clarke Ltd.). Numbers were used as targets; the corresponding vision was 0.4/40cm (Jaeger 5 or point size 8). The target was brought closer until the numbers blurred and then taken backward until the numbers were clear again. The accommodation at this point wae recorded. Each child then read for 12 minutes. The book was age-relevant with a text of about 0.4/40cm. The child read silently using the reading distance he or she preferred. The examiner sat nearby to ensure that the reading was done. The accommodation was measured before the reading session and at the end of the session. An accommodation of 7 D or less was considered decreased.3

RESULTS

At the end of the reading session, decreased accommodation was found in 19 (15.8%) of the musicians, in six (6.5%) of the athletes, and in six (5.4%) of the control group. The difference was significant between the musicians and the control group (percent t-test: 0.005<p< 0.01; t = 2.61), but not between the athletes and the control group (p>0.1; t = 0.33). The distribution of age and sex in children with decreased accommodation is shown in Table 1. Only one boy had decreased accommodation in each of the three study groups. The percentage of girls with decreased accommodation was 22.2% among the musicians, 10.4% among the athletes, and 7.7% among the control group The difference also was significant between the musicians and the control group (0.01<p<0.02; t = 2.54), but not significant between the athletes and the control group (p>0.05; t = 1.83).

The mean accommodation of the musicians, athletes, and control group at the end of the reading session is shown in Table 2. The mean accommodation of the musicians was lower than that of the control group, and the difference was significant by t-test (0.001<p<0.005; t = 3.02). The mean accommodation of the athletes and the control group did not show a significant difference (p>0.1; t=1.30). The mean accommodation of 10- to 12-year-old musicians also was significantly lower than that of the corresponding control group (0.001<p<0.005; t = 2.91). The other corresponding age and sex groups in musicians and controls or athletes and controls did not significantly differ from each other. In all groups the mean accommodation of the girls was lower than that of the boys; this reached a significant level only in the groups of all musicians, all controls, and in musicians of 10 to 12 years of age. The distribution of the accommodations in each of the three study groups in girls and boys is shown in Figures 1-3.

The refractions in the musicians varied from -5.0 to +3.75 D, in the athletes from -5.5 to +1.0 D, and in the control group from - 5.5 to +4.5 D. The distributions of the refractions in the three study groups were not significantly different by two-way analysis of variance (F = 2.43). Myopia was found in 19% of the control group, 26% of the musicians, and 27% of the athletes. There was no significant difference between these percentages.

The mean change in accommodation during the reading session was positive in children with normal accommodation. In the children with decreased accommodation, this mean change was negative in the musicians and athletes (Table 3). The weekly regular supervised time of the three study groups for instrument playing and training in sports, as well as for other hobbies, is shown in Table 4.

The range of the mean of grades in the last school report card was the same in both musicians and athletes: from 6.8 to 9.6, mean 8.1 ±0.6 (from approximately C to A, mean B - ). In the control group it was from 6.0 to 9.0, mean 7.5 ± 0.7 (from C - to B, mean C). The mean of the report cards of girls and boys or children with normal and low accommodations was not significantly different in the respective study groups.

DISCUSSION

According to this study, significantly more school children playing wind instruments had decreased accommodation, compared with children in the control group. The accommodation of children in sports training did not significantly differ from that of the control group. An interesting finding in the children with decreased accommodation was the tendency of further decreased accommodation during the reading session (Table 3). Observations of decreasing accommodation during a visual task in patients with fatigue of accommodation also have been made earlier.4

What might be the reason for the decreased accommodation in school-aged children? Several studies have shown that the ciliary muscle has an autonomic nerve supply from both the parasympathetic and sympathetic nerve systems.5-7 With the former, the accommodative power increases, and the eye is able to focus near; with the latter the accommodative power decreases, and the eye can focus far. The resting point where both autonomic nerve systems are in equilibrium is about 1 to 1.5 D.8 If the balance is continuously on the sympathetic side (eg, in a stressful life situation), this might have a cycloplegic-like effect on accommodation.9,10)

Table

TABLE 2Mean Accommodation ± SD of the Musicians, Athletes, and Control Group at the End of the Reading Session

TABLE 2

Mean Accommodation ± SD of the Musicians, Athletes, and Control Group at the End of the Reading Session

FIGURE 1: Distribution of accommodation at the end of the reading session in children playing wind instruments (girls: black bars; boys: white bars).

FIGURE 1: Distribution of accommodation at the end of the reading session in children playing wind instruments (girls: black bars; boys: white bars).

FIGURE 2: Distribution of accommodation at the end of the reading session in children with sports activities (girls: black bars; boys: white bars).

FIGURE 2: Distribution of accommodation at the end of the reading session in children with sports activities (girls: black bars; boys: white bars).

FIGURE 3: Distribution of accommodation at the end of the reading session in children in the control group (girls: black bars; boys: white bars).

FIGURE 3: Distribution of accommodation at the end of the reading session in children in the control group (girls: black bars; boys: white bars).

Table

TABLE 3Change of Accommodation From the Beginning to the End of the Reading Session in Children With Normal and Decreased Accommodation

TABLE 3

Change of Accommodation From the Beginning to the End of the Reading Session in Children With Normal and Decreased Accommodation

Table

TABLE 4Weekly Hours Spent in Regularly-Supervised Hobbies

TABLE 4

Weekly Hours Spent in Regularly-Supervised Hobbies

School and various activities in sports and music training can be very demanding. Parents, teachers, and coaches press for better achievement, more training, and more learning. Often these activities are performed more for the satisfaction of these adults than for that of the children.11-24 Sports competitions or music performances can produce stress and anxiety reactions, and the initially interesting hobby becomes filled with unbearable situations. Simon showed in her thesis that the scores of state anxiety (anxiety connected with a stressful situation) were significantly higher in school-aged band players and individual sport athletes than in team athletes or in children with no such activities.15 Although the training hours and the grades were on the same level in the girls and boys of the present study (Table 4), the girls formed the majority of the decreased accommodation group. Are girls, especially 10 to 12 year olds, more committed to their involvement in school and activities? Are they thus more susceptible to stress than boys? At the beginning of the century, Duane found three times more decreased accommodation in boys than in girls at puberty.16 At that time, primarily boys were sent to school and perhaps they also had more demanding hobbies.

Although among the band players, the number of children with decreased accommodation was significantly higher, they did not seem to differ from the other groups of children in this study: the distribution of their refractions, the amount of myopia, the time spent in regular supervised hobbies, and their achievement at school was about the same as in the other groups. Children playing instruments other than wind instruments also would be interesting to study and compare with this study. The situation of these band players, however, may be more stressful than that of the other instrument-playing children: in the former, playing a wind instrument is a school subject in elementary school, while the latter voluntarily play an instrument in their free time.

In addition to the possible psychological reasons for decreased accommodation, physiological reasons also must be considered. In adult wind instrument players, the pulmonary function has been found to be on the same level as in other musicians.17 But a study of bagpipe playing18 states that it might produce greater intrathoracic pressures and hence more cardiovascular strain than previously recognized. Further research is needed to find any physiological connection between playing a wind instrument and decreased accommodation in children.

Child athletes have been studied more than musicians. Kinderman, Keul, and Lehmann reported on 11- to 14-year-old boys who competed in a 10 km run.19 At the beginning of the competition, levels of both adrenalin and noradrenalin in the blood were above normal. During the run, excretion of adrenalin remained constant, but that of noradrenalin increased further. In another study, considerably higher catecholamine increase was found after short (100 m) and long (1500 m) distance swims than after short (200 m) distance runs.20 According to Frey, the sympathetic activation increases with the degree of physical work load, but this endocrine response to physical activity diminishes as a result of further physical training.21 Thus, at the beginning of sports activities, the catecholamine level may rise and cause a cycloplegic-like effect on accommodation. These children, therefore, could experience accommodation difficulties. Later, after the child has trained longer, the sympathetic activity is no longer at a high level, and the accommodation works normally again. This could explain why the young athletes of the present study did not have more decreased accommodation than the control group; all of these children had trained regularly for at least 1 year.

REFERENCES

1. Duane A: Studies in monocular and binocular accommodation with their clinical applications. Am J Ophthalmol 1922; 5:865-877.

2. Mäntyjärvi MI: Accommodation in hyperopic and myopic school children. J Pediatr Ophthalmol Strabismus 1987; 24:37-41.

3. Eames TH: Accommodation in school children. Am J Ophthalmol 1961; 51:1255-1257.

4. Berens C, Sells SB: Experimental studies of fatigue of accommodation II. Am J Ophthalmol 1950; 33:47-58.

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6. Hurwitz BS, Davidowitz J, Chin NB, et al: The effects of the sympathetic nervous system on accommodation. Arch Ophthalmol 1972; 87:668-674.

7. Hurwitz BS, Davidowitz J, Pachter BR, et al: The effects of the sympathetic nervous system on accommodation. Arch Ophthalmol 1972; 87:675-678.

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10. Gawron VJ: Ocular accommodation, personality, and autonomic balance. Am J Optom Physiol Opt 1983; 60:630-639.

11. Smilkstein G: Psychological trauma in children and youth in competitive sports. J Fam Pract 1980; 10:737-739.

12. Martens R: The uniqueness of the young athlete: Psychologic considerations. Am J Sports Med 1980; 8:382-385.

13. Brown RS: Exercise and mental health in the pediatric population. Clin Sports Med 1982; 1:515-527.

14. Railo WS: The relationship of sport in childhood and adolescence to mental and social health. Scand J Soc Med 1982; 29(suppl):135-145.

15. Simon JA: Children's anxiety in sport and nonsport evaluative activities. Thesis, University of Illinois at Urbana-Champaign, 1977.

16. Duane A: Anomalies of the accommodation, clinically considered. Arch Ophthalmol 1916; 45:124-136.

17. Schorr-Lesnick B, Teirstein AS, Brown LK, et al: Pulmonary function in singers and wind-instrument players. Chest 1985; 88:201-205.

18. Gibson TM: The respiratory stress of playing the bagpipes. J Physiol 1979; 291:24P-25P.

19. Kindermann W, Keul J, Lehmann M: Auedauerbelastungen beim Heranwachsenden-Metabolische und kardiozirkulatorische Veränderungen. Fortschr Med 1979; 97:659-665.

20. Weicker H: Sympathoadrenergic regulation. Int J Sports Med 1986; 7(suppl):16-26.

21. Frey H: The endocrine response to physical activity. Scand J Soc Med 1982; 29:(suppl):71-75.

TABLE 1

Distribution of Age and Sex of Children With Decreased Accommodation

TABLE 2

Mean Accommodation ± SD of the Musicians, Athletes, and Control Group at the End of the Reading Session

TABLE 3

Change of Accommodation From the Beginning to the End of the Reading Session in Children With Normal and Decreased Accommodation

TABLE 4

Weekly Hours Spent in Regularly-Supervised Hobbies

10.3928/0191-3913-19880101-03

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