Objective: To analyze the status of outdoor activities on weekends among children and adolescents of different educational stages in Shanghai and their impact on myopia, so as to provide a basis for formulating more specific prevention and control protocol of myopia. Methods: From September to October 2022, a stratified cluster random sampling method was employed to select 84 schools (27 kindergartens, 21 primary schools, 15 junior high schools and 21 high schools) across Shanghai, enrolling a total of 28 654 children and adolescents aged 4 to 18 for the study. Ophthalmic examinations were conducted to ascertain the prevalence of myopia among children and adolescents. Additionally, a questionnaire survey was administered to collect data on outdoor activity duration and associated factors. Multivariate Logistic regression analysis was utilized to investigate the associated factors of outdoor activity levels on weekends. Results: The overall myopia detection rate among children and adolescents was 58.4%, with a higher rate observed in girls (59.2%) compared to boys (57.6%). The myopia detection rates for children and adolescents with an average daily outdoor activity duration of ≥2 h and <2 h on weekends were 54.6% and 68.8%, and the differences were statistically significant ( χ 2=8.12,460.89, P <0.01). Multivariable Logistic regression analysis revealed that girls ( OR =0.80), those with a myopic parent ( OR =0.68), schools from urban districts ( OR =0.72), higher education stages (primary school: OR =0.65, junior high school: OR =0.24, high school: OR =0.14) and spending≥2 h/d on homework during weekends ( OR =0.57) among children and adolescents were less likely to engage in outdoor activities for ≥2 h on weekends ( P <0.01). After incorporating gender, parental myopia status, educational stage, school location, average daily duration on weekends for spending on homework, electronic product usage and outdoor activities as dependent variables in a multivariate Logistic regression analysis, the results showed that children and adolescents with an average outdoor activity duration for ≥2 h on weekends had a lower risk of myopia ( OR =0.86, P < 0.01). Conclusions The level of outdoor activity among children and adolescents on weekends needs to be improved. Outdoor activities on weekends is an associated factor for myopia among children and adolescents. Particularly, girls, those with myopic parents, schools from urban districts, and spending long hours on homework during weekends among children and adolescents require increased attention.

Objective: To investigate the visual acuity and correction conditions of children and adolescents in Shanghai, so as to provide a scientific basis for developing intervention measures to prevent myopia and protect vision among children and adolescents. Methods: From October to December 2022, a stratified cluster random sampling survey was conducted, involving 47 034 students from 16 municipal districts in Shanghai, covering kindergartens (≥5 years), primary schools, middle schools, general high schools and vocational high schools. According to the Guidelines for Screening Refractive Errors in Primary and Secondary School Students, the Standard Logarithmic Visual acuity Chart was used to examine naked vision and corrected vision of students, and general information was collected. The distribution and severity of visual impairment in different age groups were analyzed, and χ 2 tests and multivariate Logistic regression were used to explore factors associated with visual impairment. Results: The detection rate of visual impairment among children and adolescents was 76.2%, with a higher rate among females (78.8%) than males ( 73.8 %), higher among Han ethic students ( 76.2 %) than minority students (71.2%), and higher among urban students (76.7%) than suburban students (75.8%), all with statistically significant differences ( χ 2=162.6, 10.4, 5.5, P <0.05). The rate of visual impairment initially decreased and then increased with age, reaching its lowest at age 7 (53.8%) and peaking at age 17 (89.6%) ( χ 2 trend = 3 467.0 , P <0.05). Severe visual impairment accounted for the majority, at 56.6%, and there was a positive correlation between the severity of visual impairment and age among children and adolescents ( r =0.45, P <0.05). Multivariate Logistic regression showed that age, BMI, gender, ethnicity and urban suburban status were associated with visual impairment ( OR =1.18, 1.01, 1.38 , 0.79, 0.88, P <0.05). Among those with moderate to severe visual impairment, the rate of spectacle lens usage was 62.8%, yet only 44.8 % of those who used spectacle lens had fully corrected visual acuity. Females (64.9%) had higher spectacle lens usage rates than males (60.6%), and general high school students had the highest spectacle lens usage (83.9%), and there were statistically significant differences in gender and academic stages ( χ 2=57.7, 4 592.8, P <0.05). Conclusions The rate of spectacle lens usage among students with moderate to severe visual impairment is relatively low, and even after using spectacle lens, some students still do not achieve adequate corrected visual acuity. Efforts should focus on enhancing public awareness of eye health and refractive correction and improving the accessibility of related health services.

AIM: To compare the agreement between the ARK Biometer Combo and OA 2000 in patients wearing orthokeratology lenses.METHODS: A prospective study. A total of 148 patients(148 eyes)who were wearing orthokeratology lenses and returned for follow-up at the Shanghai Eye Disease Prevention and Treatment Center from August to September 2024 were included. Biometric measurements were performed using both the ARK Biometer Combo and OA 2000. Parameters including axial length(AL), corneal central thickness(CCT), anterior chamber depth(ACD), lens thickness(LT), corneal curvature(Kf and Ks), astigmatism(AST), white-to-white corneal diameter(WTW)and pupil diameter(PD)were obtained. Differences in measurement parameters between the two biometers were compared, and agreement was assessed.RESULTS: There were no statistically significant differences in the measurements of Kf, Ks and AST between the two biometers(P>0.05). Statistically significant differences were found in the measurements of AL, CCT, ACD, LT, WTW and PD(t=2.559, P=0.012; t=16.771, P<0.0001; t=4.749, P<0.0001; t=-15.212, P<0.0001; t=-14.915, P<0.0001; t=-2.402, P=0.018). ICC ranged from 0.615 to 0.999. Bland-Altman analysis showed that the maximum absolute values of the 95% limits of agreement(LoA)of AL, CCT, ACD, LT, Kf, Ks, AST, WTW and PD were 0.07 mm, 35.07 μm, 0.07 mm, 0.12 mm, 0.66 D, 1.14 D, 1.00 D, 0.76 mm, and 0.98 mm, respectively.CONCLUSION: In orthokeratology patients, the ARK Biometer Combo and OA 2000 showed good agreement in measuring AL, CCT, ACD, Kf and LT, and can be used interchangeably.

Objective:To study the distribution and changes of dopamine transporter (DAT) in guinea pig eyes under different light patterns.Methods:Thirty-six 3-week-old white ordinary-grade guinea pigs were randomly selected and divided into groups of 10 000 lx, 5 000 lx, and 500 lx, with 12 guinea pigs in each group exposed to strong light, medium strong light, and normal light, respectively.Each group was randomly divided into 3 subgroups, with 4 guinea pigs in each subgroup.The 3 subgroups of 500 lx group received light exposure for 5, 20, and 40 minutes, respectively.The 3 subgroups of 5 000 lx group received light exposure for 2, 4, and 40 minutes, respectively.The 3 subgroups of 10 000 lx group received light exposure for 2, 5, and 20 minutes, respectively.After light treatment, each group of guinea pigs was injected with 99mTc-TRODAT-1 for SPECT DAT imaging, and image data were collected by Micro-SPECT.The region of interest (ROI) of guinea pig retinas was analyzed using Micro-CT software.The counts of ROI were expressed as Sum, which reflected the relative distribution or density of DAT.The DAT density between experimental and control eyes of guinea pigs after light exposure, the differences in DAT density between guinea pig eyes under different light intensities, the differences in DAT density between guinea pig eyes after different light durations, and the cumulative and interactive effects of light intensity and light duration on DAT aggregation in guinea pigs were compared.Another 3 guinea pigs were selected, and after light exposure, the 3 guinea pigs' eyes underwent continuous image acquisition for 6 hours at 20-minute intervals, and 18 images per guinea pig were acquired to analyze the trend of DAT density in guinea pig eyes over time.This study was approved by the Ethics Committee of Shanghai General Hospital (No.2020SQ196). Results:The DAT density (Sum value) of experimental eyes at 500, 5 000, and 10 000 lx were 5 598.97±3 159.38, 8 636.78±2 503.16, and 7 407.39±2 053.41, respectively, significantly higher than 4 388.89±2 902.90, 5 981.92±3 057.44, and 5 091.32±2 039.36 of control eyes ( t=5.31, 4.69, 11.80; all at P<0.001). At 500 lx, there was a statistically significant difference in DAT density between the experimental and control eyes of guinea pigs at different light exposure durations ( F=14.01, P<0.01), while no significant difference was found at other light intensities at different light exposure durations (both at P>0.05). When the light exposure time was 5 minutes, the difference in DAT density between the experimental and control eyes of guinea pigs was significantly greater in the 10 000 lx group than in the 500 lx group ( t=-13.22, P<0.001). There was no statistically significant difference between different groups at other light exposure durations (all at P>0.05). No cumulative or interactive effects of light intensity and light duration were found on the differences in DAT density (all at P>0.05). Continuous scanning after illumination showed that DAT density in guinea pig retinas first increased to a peak over time and then gradually returned to normal values. Conclusions:Light, even under moderate or normal light levels, can cause an increase in the secretion of DAT in the retina and stimulate the production of DAT.Light intensity and duration have no cumulative or interactive effects on the distribution and density of retinal DAT.

Objective: To explore the association between parental education level and time spent outdoors among children, so as to provide the scientific evidence for formulating policies of myopia prevention and control among children. Methods: The study was based on secondary analysis of data from outdoor intervention studies in Shanghai. The follow up period was from March to December 2018. It included control group children ( n =1 117) with complete questionnaire surveys, ocular examinations, and time spent outdoors. Generalized linear regression models and trend tests were used to analyze the effect of parental education level on time spent outdoors among children. Results: The median time spent outdoors was 76.4(59.7, 94.6) minutes. After adjusting for covariates including children s sex and age, generalized linear regression model suggested that there was no statistical significance between father s education level and outdoor activity time ( P >0.05). Compared with children whose mothers had a junior high school education or below, children whose mothers had high school/vocational high school education, college or above had shorter time spent outdoors ( β=-6.64, -8.84 , P <0.05). Trend tests revealed that time spent outdoors among children decreased with the increase of parental education level ( P trend <0.01). Conclusions The higher the education level of fathers or mothers, the shorter time spent outdoors of children. In addition to highlight outdoor activities at school, myopia prevention and control efforts should be focused on the role of parents in increasing children s outdoor activities.

OBJECTIVE: The current fertilization methods for Chinese yam are uneconomic and unfriend to environment. A rational one is very important to achieve desired balance of high yield of Chinese yam, economic and friend to environment. Here, we studied the effects of nitrogen (N), phosphorus (P), and potassium (K) fertilizers on the yield of 'Qinfeng' Chinese yam in shallow-groove directional cultivation. METHODS: The experiments were conducted in Dehua County, Fujian Province, China using a "3414" optimal design. Overall, three fertilizer factors (N, P, and K) were evaluated at the following four levels: 0, no fertilizer; 1, 0.5-fold the typical rate; 2, typical fertilization rate; and 3, 1.5-fold the typical rate. There were 14 different fertilization treatments. RESULTS: Treatment 6 (N₂P₂K₂) produced the longest (75.6 cm) and thickest tubers (4.9 cm) with the highest tuber fresh weight (1311.9 g) and yield (41 015.9 kg/hm²), whereas, treatment 1 produced the shortest (65.6 cm) and thinnest tubers (3.9 cm) with the lowest fresh weight (953.4 g) and yield (28 532.8 kg/hm²) among the 14 fertilizer combinations. The experimental data could be fitted to single-variable quadratic and binary quadratic models but not to a ternary quadratic polynomial model. Appropriate N, P, and K fertilizer application rates increased Chinese yam yield. However, excessive fertilization lowered the yield. Chinese yam yield was significantly and strongly correlated with the amounts of N, P, and K fertilizer applied. CONCLUSION Based on the single variable quadratic and binary quadratic models, we propose that the quantities of N, P, and K fertilizer used to grow 1 hm² 'Qinfeng' Chinese yam should be 360-388.3, 90-100.95, and 416.3-675 kg, respectively.

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 analyze the effect of sunlike spectrum LED illumination on retinal blood flow perfusion, and to explore the the correlation between sunlike spectrum LED illumination and eye health indicators in children and adolescents. Methods: A randomized control double blind trial was conducted. The ordinary LED table lamp in the control group(11) and the sunlike spectrum LED table lamp in the experimental group(12) had a fitting degree of 87% and 95% with the daylighting spectrum, respectively. Two sample independent t test and multivariable linear regression model were applied to compare the changes of retinal blood perfusion before and after the trial. Results: After near reading for 1 hour, the retinal capillary density in the superficial and deep layers of the subjects in the ordinary LED illumination group decreased (superficial layer: -3.05±2.04 , P <0.01; deep layer: -4.03± 4.94, P =0.02), no significant decrease was found in the sunlike spectrum LED illumination group (superficial layer: -0.59± 1.44, P =0.18; deep layer: -0.49±4.27, P =0.70). Multivariable regression analysis found that compared with ordinary LED illumination, sunlike spectrum LED illumination could significantly alleviate the decrease in capillary density in the superficial and deep retinal layers, respectively ( β =2.83, 95% CI =1.54-4.12, P <0.01; β =4.21,95% CI =0.58-7.84, P =0.02). Conclusion Sunlike spectrum LED illumination can alleviate the decrease in retinal blood perfusion caused by near work among children and adolescents, suggesting that it may delay the onset and development of myopia. Prevention and control of myopia needs to pay attention to the spectral power distribution of artificial illumination.

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.