| Objective:In the past twenty years, with short-sightedness and myopia increasingly being reported among the child and adolescent students, questions arise as how the genetic and environmental factors involve in the development and progression of myopia, and how to perform useful interventions. Actually, short-sightedness and myopia are hazardous to the health and development of the children and adolescents.Regarding the high prevalence of myopia among the students of Shanghai, a series of interventions have been conducted jointly by the Shanghai Municipal Education Committee and Shanghai Health Bureau. However, with the greater near work demands as well as computers and electronic devices longer using hours, the nearwork-induced myopia seems more common. On this basis, a relatively healthy visual environment is indispensable in terms of reducing the risk of myopia development. In Shanghai, however, school exercise books with very narrow ruling width being used in elementary and secondary schools are regarded as one of the risk factors relating to myopia development and progression, for which the visual fatigue is being induced. Up to now, there is no health specification for ruling width in China, so as to school exercise books with very narrow ruling width appear on the market. The increasing prevalence rate of myopia possibly attributes to a rise in reading activity with the unhealthy visual environment, and then a hypothesis is that the narrow ruling width of school exercise books exacerbates the development and progression of myopia but there is no extensively study in either cross-sectional studies or cohort studies.So the aim of this study is to figure out the writing small character habit in relating to the occurrence and development of child and adolescent students’ myopia, so as to provide epidemiology evidence for changing the rulings width of school exercise books for the prevention of the development and progression of myopia. To utilize quantitative research method for formulating the ruling width standard scientifically in the Health Specification for Elementary and Secondary School Exercise Books in terms of eye protection and healthy development. Methods:As to quantitative research, a total of3498students,3399student parents as well as166school teachers of2nd,3rd,4th and7th grade of12elementary and secondary schools in Shanghai were surveyed by self-administered questionnaire for grasping the current situation of writing habit in school exercise books. Data of routine vision screening of the respondents’from2009till2010had been used. The chart light illumination was500lx and the distance between the subjects and the chart was5-meter far. After vision examination, the students were organized to take computerized refractive examination. And data analysis was using SPSS Package for Windows (Version15.0).On the basis of optical study findings along with actual ruling width of foreign school exercise books, three kinds of exercise books with different ruling width were on trail among the students, parents and school teachers, so as to decide which kind of ruling width was preferred in terms of visual comfort.Results:Of the3498participant students, the habit of writing small character habit is common relied on both self-administrated questionnaire and objective assessment performed by investigators. The prevalence rate of writing small characters is as high as30%and nearly40%relied on self-administrated questionnaire and objective assessment, respectively.Comparisons of bare visual acuity, spherical equivalent, axial length, the prevalence rate of suspected myopia index during the routine vision screening in2010between writing-small-character participants and non-writing-small-character participants were conducted. In7th grade students, it was found that bare visual acuity index was significantly lower for writing-small-character participants than those of non-writ ing-small-character group, and the prevalence rate of suspected myopia index was significantly higher for writing-small-character participants, but the difference of either of them was not significant in other three grades. In2nd grade students, there was statistically significance of spherical equivalent index between two groups of writing-small-character and that of non-writing-small-character.Comparisons of the difference of bare visual acuity, spherical equivalent, axial length, the incidence rate of suspected myopia index during past two vision screening checkups in2009and2010between writing-small-character participants and non-writing-small-character participants were conducted. In3th grade students, it was found that the incidence rate of suspected myopia index was significantly higher for writing-small-character participants than those of non-writing-small-character group, but the difference of the incidence rate of suspected myopia index was not significant in other three grades. And there was not statistically significance of the difference of bare visual acuity, spherical equivalent, axial length index of the two vision screening checkups in all of the four grades.Secondly, independent impact of writing small character on the development and progression of suspected myopia was examined by using multiple logistic regression analysis with the covariation effect of gender, study stress, myopia of the parents, near work habit, sleep duration time, electronic device duration time, and outdoor activity duration time being controlled. Odds ratio of writing small character towards the prevalence of suspected myopia and the incidence of suspected myopia were1.717(1.045-2.821)and1.819(1.076-3.075) in7th grade and3th grade students, respectively.Three kinds of exercise books with different ruling width were on trail among the students, parents and school teachers. The results show that the ruling width of2#books was preferred in terms of visual comfort among the students of3rd,4th and7th grade and all the parents and teachers. That is to say, the specification of ruling width formulated could be applied in the Health Specification for the Elementary and Secondary School Exercise Books.Conclusion:The low vision and suspect myopia show a high prevalence rate among the primary and secondary school students in Shanghai. Due to the specific characters of the growth and development of the children and adolescents, it is really easy for them to feel visual stress after close visual work. As a matter of fact, if the students are used to writing the small characters and identifying these smaller signals that will always push their ciliary muscle into an intense contraction. Therefore, the government is supposed to present some specifications for the ruling width of school exercise books, and help to create a favorable close visual environment for the students’eye health. Moreover, the health educations of eye care are supposed to be delivered to the students, parents and teachers which will be beneficial and helpful for their eye health. |
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