Abstract In recent years, the state has paid greater attention to the prevention and control of myopia in children and adolescents, as well as to the issuance of corresponding policies, which means that this issue has once again become the focus of work in the fields of school health and ophthalmology. It should be noted that the prevalence of myopia has continued to rise for many years and it has reached a very high level. Therefore, reducing its prevalence requires long-term evidence-based prevention and treatment strategies, and a shift from “quantitative change” to “qualitative change”. However, there is still a lack of high-quality research evidence regarding many aspects of myopia prevention and control. This paper summarizes the existing evidence and identifies limitations, proposes a direction for future efforts, and puts forward some suggestions regarding key aspects, such as the selection of evaluation indicators for myopia prevention and control, interventions that aim to increase the time spent on outdoor activities, standardized screening and closed-loop management, and the exploration of effective prevention and control measurements, so as to provide a referential framework that can be used to scientifically develop and implement myopia prevention and control strategies, as well to evaluate their efficacy.

Objective: To understand the correlation between myopia related health belief and screen time of primary and secondary school students in Jing-an District of Shanghai, and to provide suggestions for reducing screen time and preventing myopia. Methods: Using the method of cluster sampling,1 585 students from grade one to grade eight of a primary school and a junior high school in Jing-an District were selected for a questionnaire survey regarding myopia related health belief, screen time and the correlation between them. Results: About 18.8%-44.4% of the students perceived themselves as myopia susceptible,which increased with grade (χ 2=33.25,P<0.01), 51.5%-78.0% of the students were aware of the adverse health impart of myopia, 39.3%-55.6% of the students were aware of unhealthy behaviors associated with myopia and 48.7%-77.5% of the students. More than 47.6% of the students daily screen time was more than 2 h/day, and daily screen time increased with grade (χ 2=12.18, P<0.01). Perceived susceptibility for myopia, awareness on adverse health impact of myopia and unhealthy behaviors associated with myopia, as well as self-efficacy associated with myopia prevention were associated with screen time of students. Conclusion The primary and middle school students in Jing an District show low lever of knowledge on myopia susceptibility and threat, but higher lever of knowledge on myopia severity and self-efficacy of preventing myopia. nearly half of the students use electronic screens too long or too close to their eyes. Awareness on myopia susceptibility, myopia-related behaviors and health impacts of myopia and self-efficacy, combined with screen time reduction might help myopia prevention.

Objective: To investigate the prevalence of myopia and sleep quality among adolescents in Baoshan District of Shanghai, and to further analyze the association between different degree of myopia on sleep quality. Methods: A total of 777 adolescents aged 9-16 years were selected by stratified cluster random method, and ophthalmology examination and Pittsburgh Sleep Quality Index (PSQI) Chinese version scale and related factors questionnaire were conducted. Results: The prevalence rates of myopia and sleep disorders were 68.08% and 13.77% respectively in Baoshan District of Shanghai. With the increase of age and grade, the prevalence of myopia and sleep disorder increased(χ 2=139.58, 114.17；58.00, 56.41, P＜0.01).There were significant differences in sleep disorders among different degree of myopia groups (χ 2=24.57,P<0.01), including sleep time, progressive function and PSQI total score were statistically significant (F=9.65, 7.22, 4.38, P<0.01). Logistic regression analysis showed that moderate to high and high myopia were risk factors for sleep quality of adolescents (β=0.87, 0.95, OR=2.38, 2.59, P<0.05). Conclusion The prevalence of myopia and sleep disorder among adolescents in Baoshan District of Shanghai is high, myopia shows impacts on sleep quality of adolescents at a certain level. Adolescents with high myopia have a higher risk of sleep disorders.

Abstract China has one of the world’s highest prevalence of myopia in children and adolescents, and children are developing myopia earlier. Myopia has become a important issues affecting children and adolescents health, as well as a significant public health concern. There has been continuing debate over the role of nature and nurture in the aetiology of myopia, growing evidence showed that environmental factors has a determine effect on myopia.The randomized controlled trials has assured the relationship between time outdoors and myopia. Based on reviewed published articles, survey and intervention studies and school health practices, according to the principle of school organization, student participation and family cooperation, the authors proposed outdoors activities as initiative for myopia prevention and control in children and adolescents. The detail recommendation contents, levels were list out.

Objective: To understand the referral rate in children with abnormal refractive error in screening programs and associated factors, aiming to provide evidence for improving the rate and myopia prevention and control in the future. Methods: Using cluster sampling, three primary schools and three junior middle schools in Huangpu District, Shanghai were selected. All students were archived for refractive development, including examinations such as visual acuity, non cycloplegic autorefraction and axial length. The follow up visit and related factor information were collected through questionnaire, and the influencing factors of referral rate were analyzed by multivariate Logistic regression. Results: A total of 2 104 high risk children and adolescents with suspected refractive abnormalities were suggested follow up visit, and the actual referral rate was estimated to be 60.4%; the rate of referral to designated hospitals was estimated to be 58.8%. Nonconditional Logistic regression analysis showed that myopic status before the screening( OR=1.37, 95%CI =1.08-1.72), wearing spectacles or ortho contact lens( OR=2.05, 95%CI =1.62-2.59), myopic degree ( OR below -0.5 D =2.08, 95% CI =1.48-2.92, OR -3.0~-0.5 D =1.86, 95% CI =1.47-2.36), parents familiarity with screening results( OR=2.92, 95%CI =1.89-4.50), parents satisfaction with suggestions after screening ( OR=3.54, 95%CI =1.16-10.79) were significant factors associated with the referral rate( P <0.05). Conclusion The actual referral rate among children and adolescents needs to be improved. It is necessary to further optimize the informatization of refractive archives, strengthen popular science education for key population, standardize the professional interpretation of preliminary screening refractive examination results, improve parents awareness, participation and satisfaction through health education, and achieve the whole process management of refractive archives.

Objective: To investigate the refractive progression and associated factors of children of different ages and refractive status, and to provide guidance on myopia prevention and control program formulation and work practice. Methods: A total of 20 kindergartens, primary schools, and secondary schools in 2 districts of Shanghai were selected based on the existing cohort, and baseline data in 2015 and one year follow up data in 2016 were collected from 1 510 children aged 4 to 14, including cycloplegic spherical equivalent refraction (SER), axial length (AL), and corneal curvature. The distribution and progression of SER and AL in children of different ages and refractive status were analyzed, and the influencing factors of SER progression (ΔSER) were explored using multiple linear regression. Results: ΔSER remained relatively stable at age 4 and 5 (average -0.08 to -0.07 D/year), and SER drifted significantly towards myopia (average -0.50 to -0.31 D/year) in all groups older than 6 years, dropping back to -0.44 to -0.33 D/year after age 11; Elongation of AL (ΔAL) was 0.27 to 0.35 mm/year in 4 to 10 years group, and decreased to 0.15 to 0.22 mm/year in 11 to 14 years group. The ΔSER and ΔAL were greatest in the new onset myopes [(-0.90± 0.05 )D, (0.51±0.02)mm], followed by the low myopia group [(-0.68±0.04)D, (0.36±0.02)mm], then followed by the moderate to high myopia group[(-0.49±0.06)D，(0.23±0.03)mm] and the lowest in the hyperopia group[(-0.21±0.02)D, ( 0.26 ±0.01)mm], with a statistically significant difference among these groups ( P <0.05). Age ( β =-0.07), baseline SER ( β = 0.05 ) and ΔAL ( β =-0.78) were independent influencing factors for refractive progression in the 4 to 10 years old group, while ΔAL( β =-1.55) was the only independent influencing factor in the 11 to 14 years old group ( P <0.05). Conclusion The elongation of AL in preschoolers is mostly physiologically and should be prevented from growing beyond the physiological range by increasing outdoor activities. The primary students, as well as students with pre myopia or low myopia are the priority groups for dynamic monitoring and intervention in myopia prevention and control.

Objective: To explore the effect of puberty on refractive development of children and adolescents and its interaction with outdoor activities, near work and the use of electronic products, so as to provide a reference for strategies for intervening myopia. Methods: Cluster sampling method was used to select 776 students aged 7-13 from a nine year consistent school in Shanghai to participate and were followed up for 2 years. All participants underwent cycloplegic refraction and ocular axial length measurement once a year, as well as pubertal development, average daily outdoor time, near work time and time of electronic products usage. The influencing factors and interaction effects of refractive parameters in different puberty stages were analyzed by generalized estimation equation. Results: At baseline, 634 children participated in cycloplegic refraction, of which 350 were myopic (55.2%). There were significant differences in axial length, average daily outdoor time, near work time and time of using electronic products at different stages of puberty ( F = 4.10 ，4.24，5.54，9.20， P <0.05). There was interaction between puberty and outdoor time on axial length development ( β =0.133, P < 0.05), and the interaction between puberty and the time of near work or using electronic products was not statistically significant ( P >0.05). Conclusion Puberty may play a regulatory role in the relationship between outdoor time and refractive development among Chinese children and adolescents.

Objective: To understand the online learning related screen use duration and screen types in school aged children in Shanghai during the COVID-19 epidemic. Methods: Random clustering sampling was used to select 5 591 parents of students from 8 primary and junior schools that are in the sampling pool of the national myopia survey in districts of Jiading, Pudong and Baoshan in Shanghai in April 2020. Electronic questionnaire was administered to parents regarding their child s online learning related screen use. Results: On average, the median weekly duration of online learning related screen use was 13.33 hours, the curricular and extracurricular parts of which were 10(8.75，16.67) and 0(0，3.33) hours, respectively. About 29.44% of investigated school aged children only used small size screen for online learning. Children in higher grades, being myopic and parents neither being myopic were associated with reporting higher weekly duration( P <0.05); children in higher grades of primary school and parents neither being myopic were associated with a higher likelihood of using small size screen for online learning( P <0.05). Conclusion At the early stage of the COVID-19 epidemic, the burden associated with online learning related screen use was high in school aged children in Shanghai. Health education regarding online learning related screen use should be addressed in parents to guide their children to use screen appropriately.