Standard Logarithmic Visual Acuity Research Articles

Primary intraorbital inflammatory lumpy lesion: A rare case report.

Eosinophilic angiocentric fibrosis (EAF) is considered to be a kind of benign IgG4-related disease, and it is more often found in the nasal cavity. We present a pretty rare case of orbital EAF that is unlike any other reported case for this case is an IgG4 negative orbital EAF and successfully treated by the fronto orbitozygomatic approach surgery. This is a 68-year-old man from a rural area of Inner Mongolia Autonomous Region, went to our hospital for a 2-month history of vision loss with a local hospital orbital computer tomography which showed that there was a lesion in his left orbit. The inspection of the patient revealed that the patient left eye was protruding outward and the left eyelid unable to complete open or close. And his left eyeball movement had difficulty in all directions. Postoperative pathology diagnosed that this was a case of IgG4-negative EAF case. Orbital EAF. Surgical radical resection and postoperative glucocorticoid therapy. After surgery, the left eye vision of this patient increased to 0.6 tested in the standard logarithmic visual acuity chart. And his left eyeball movement dysfunction and eyeball outward protruding get a partially relief. EAF occurring in the orbit is a very rare disease and immunohistochemical results of EAF can be IgG4 negative.

Association between maternal fasting glucose levels throughout pregnancy and preschoolers' refractive errors.

We aimed to investigate the association between maternal fasting plasma glucose (FPG) trajectories during pregnancy and children's refractive errors at 6 years old. Based on the Ma'anshan Birth Cohort (MABC) in China, a total of 1987 mother-child pairs were included in this study. Using the group-based trajectory model, trajectory fitting was performed on fasting blood glucose levels during the first, second, and third trimesters of pregnancy. Children's vision was measured at 6 years of age using the standard logarithmic visual acuity E-chart and cycloplegic refraction examination. Logistic regression models and multi-informant generalized estimating equations were used to analyze the association between maternal blood glucose level and 6-year-old children's visual acuity. Children born of mothers with high level FPG trajectory had a higher risk of developing refractive error [OR=1.46 (95% CI 1.08 1.97)], hypermetropia [OR=1.64 (95% CI 1.09, 2.46)] and astigmatism [OR=1.60 (95% CI 1.06, 2.41)] at age six compared to those with low level trajectory. Maternal blood glucose level in the first [β=-0.012 (95% CI -0.024, -0.001)] and the second [β=-0.016 (95% CI -0.025, -0.006)] trimesters was associated with 6 year children's distance vision value. High level of fasting plasma glucose trajectories during pregnancy has been observed to be associated with 6-year-old children's refractive error, hypermetropia and astigmatism. The first and the second trimesters may be critical periods for the effects of maternal blood glucose on children's vision. The long-term effect of maternal glucose metabolism on children's visual development deserves further study.

Renal impairment may indicate postoperative low vision in young patients with proliferative diabetic retinopathy undergoing vitrectomy.

To innovatively evaluate the impact of renal impairment in young work age patients with proliferative diabetic retinopathy (PDR) on their visuality after vitrectomy. To find out whether it is possible to better predict the improvement of visual acuity after vitrectomy in working-age people without adding additional preoperative testing. In view of the fact that diabetic retinopathy and diabetic nephropathy are common diabetic complications of microvascular damage, it is considered whether preoperative renal function can be used as this evaluation index. This paper studies the design under this theme. This retrospective study included 306 patients (306 eyes) diagnosed with PDR and undergoing vitrectomy in our hospital from January 2016 to June 2023. Relevant baseline data were collected, including age, history of kidney disease and clinical laboratory test results. According to the International Standard Logarithmic Visual Acuity Checklist, the best corrected visual acuity was tested on the first day of admission and one month after surgery, and the difference between the two was subtracted. A difference >0 was defined as "vision improved". Patients were classified as vision-improved group (n=245) and non-improved group (n=61). The differences in baseline serum urea nitrogen, creatinine, uric acid, Cystatin C, estimated glomerular filtration rate (eGFR) and urine protein distribution between the two groups were statistically analyzed, binary regression analysis was performed for meaningful parameters, and random forest model ranked the characteristics in importance. 1.A higher level of serum cystatin C [1.02(0.80,1.48) mg/L vs 0.86(0.67,1.12) mg/L, P<0.001] and a lower eGFR [82.3(50.33, 115.11) ml/(min/1.73m²) vs 107.69(73.9, 126.01) ml/(min/1.73m²), P=0.002] appeared in the non-(vision-)improved group compared with the vision-improved group. 2. The occurrence of preoperation proteinuria history of nephropathy take a larger proportion in non-improved group. 3. Univariate regression analysis showed history of nephrology (OR=1.887, P=0.028), preoperative serum urea nitrogen (OR=0.939, P=0.043), cystatin C (Cys-C) concentration (OR=0.75, P=0.024), eGFR (OR=1.011, P=0.003) and proteinuria (OR=3.128, P<0.001) were influencing factors to postoperative visual acuity loss in young working age PDR patients. Excluding other confounding factors, preoperative proteinuria is an independent risk factor for postoperative vision improvement in working-age PDR populations (OR=2.722, P=0.009). 4. The accuracy of the prediction random forst model is 0.81. The model appears to be superior in terms of positive prediction. In young work aged PDR patients undergoing vitrectomy, preoperative urine protein can be an independent indicator of postoperative visual loss. Aggressive correction of kidney injury before surgery may help improve postoperative vision in patients with PDR.

Association between body stature and prevalence of reduced visual acuity in high school graduates in Hangzhou, China

ABSTRACT Clinical relevance The association between myopia and body stature is of great significance for understanding prevention and control of myopia. It has been extensively studied in previous studies but without consistent conclusions. Background The aim of this study is to investigate the association between body stature and prevalence of reduced visual acuity in high school graduates in Hangzhou, China. Methods 50,620 high school graduates who finished the physical examination of the national college entrance examination in 2020 were included. Data were derived from the database of physical examination of the national college entrance examination. Height and weight were measured, and body mass index (BMI) was calculated according to the general formula. Visual acuity was measured by the standard logarithmic visual acuity chart. Results The prevalence of reduced visual acuity was 90.38% in high school graduates. Girls had a higher prevalence of reduced visual acuity than boys (93.07% vs 87.60%, P < 0.001). Boys with normal visual acuity were significantly taller (P < 0.001) and heavier (P < 0.001) than those with reduced visual acuity. Girls with normal visual acuity were significantly taller than those with reduced visual acuity (P < 0.001). The prevalence of reduced visual acuity was significantly inversely associated with height in both boys (P < 0.001) and girls (P < 0.001). The risk of reduced visual acuity was the lowest in the fourth quartile of height. The prevalence of reduced visual acuity was significantly associated with BMI only in boys (P < 0.001). The risk of reduced visual acuity was the lowest in the third quartile of BMI. Conclusions The prevalence of reduced visual acuity was inversely associated with height in both boys and girls, and there was a U-shaped association with BMI only in boys.

Prevalence and influence factors for myopia and high myopia in schoolchildren in Shandong, China.

The aim of the study was to identify the prevalence and risk factors of myopia and high myopia in students from primary school and junior high school in Shandong. A total of 35,614 subjects completed the visual acuity test, refraction error measurement, and questionnaire in 2019. The visual acuity test was performed using the standard logarithmic visual acuity chart and the refractive error was measured by an automatic refractometer without cycloplegia. The average age was 12.38 ± 1.78 years, with 18,501 boys and 17,113 girls. The overall prevalence of myopia and high myopia was 68.02% and 5.90%, respectively, and reached up to 85.54% and 13.13% for the grade 9 students. The risk factors included girls, parental myopic history, time spent doing homework, and less sleep time. Performing eye exercise was significantly associated with a lower risk of myopia. Use of mobile devices and reading while lying down were only related to myopia, not high myopia. The prevalence of myopia and high myopia is at a high level. In addition to genetic factors, continuous close work and a lack of sleep was an important factor associated with children myopia and high myopia.

Associations between reading and writing postures and myopia among school students in Ningbo, China.

BackgroundWe conducted this study to investigate the prevalence of myopia among school students in Ningbo and to explore the associations between reading and writing postures and myopia.MethodsA population-based and cross-sectional study was conducted, and 3,256 school students aged 8–19 years were recruited. Each enrolled subject was assessed for uncorrected distance visual acuity (UDVA) using a standard logarithmic visual acuity E-chart and a non-cycloplegic autorefraction examination. Self-administered questionnaires were used to investigate myopia-related reading and writing postures and behavioral habits among school students.ResultsThe prevalence of myopia among primary school, middle school, and high school students was 61.49, 81.43, and 89.72%, respectively. Regarding the associations between reading and writing postures and myopia, we identified that a reading distance >33 cm is a protective factor for myopia in female students [odds ratio (OR) = 0.31, 95% confidence interval (CI) = 0.15–0.64], in both primary school (OR = 0.55, 95% CI = 0.30–0.99) and middle school (OR = 0.37, 95% CI = 0.15–0.90).ConclusionsA reading distance >33 cm can be used as an additional measure to prevent and control myopia. Proper postural measures for reading and writing may have educational and public health benefits.

Visual acuity of urban and rural adults in a coastal province of southern China: the Fujian Eye Study.

To evaluate the vision status and sociodemographic associations of visual acuity (VA) in an urban and rural population in a coastal province of southern China. The Fujian Eye Study, a population-based cross-sectional study, was performed from May 2018 to October 2019. Totally 10 044 participants over 50 years old from all nine cities in Fujian Province were enrolled, and underwent a questionnaire and a series of standard physical and ocular examinations. VA was measured by E Standard Logarithmic Visual Acuity Chart (GB 11533-1989). Data was double entered with EpiData v3.1 for data collation and Stata/SE statistical software v15.1 was used to analyze the data. Totally 8211 (81.8%) participants were finally included and were divided into urban populations (4678 subjects), rural populations (n=3533), coastal residents (n=6434), and inland residents (1777 subjects); 4836 participants were female. The mean age was 64.39±8.87y (median 64y; range 50-98y). The mean presenting VA was 0.61±0.30 (0.23±0.27 logMAR), and the mean best corrected visual acuity (BCVA) was 0.82±0.28 (0.08±0.19 logMAR). In the multiple regression analysis, BCVA was significantly correlated with several socioeconomic and biologic factors, including age (P<0.001), education level (P<0.001), income (P=0.005), rural residency (P<0.001), inland residency (P=0.001) and refractive error (P<0.001), while sex (P=0.194) was independent with BCVA. Accessible services and eye health policies targeting the elderly, people with high myopia and people living in rural or inland areas are needed.

The incidence of myopia and myopic progression from 2019 to 2020 in school-age children in Zhuozhou

Objective: To analyze the changes in refractive status and prevalence of myopia in 6-to 14-year-old children at 2 time points in Zhuozhou, Hebei Province. Methods: In the current cohort study, the visual acuity and refractive status of primary and secondary school students aged 6 to 14 years were examined from June to August 2019 and reexamined from June to August 2020. A total of 30 412 subjects with examination data were enrolled, including 15 861 males (52.2%) and 14 551 females (47.8%), with an average age of (10.0±2.7) years. The participants underwent autorefraction without cycloplegia and a naked eye visual acuity test with a standard logarithmic visual acuity chart. Myopia was screened by the standard of equivalent spherical refraction less than -0.75 diopter (D). The categorical data were analyzed by the Chi-square or Fisher's exact test. Clopper-Pearson was used to estimate the 95% confidence intervals for the incidence of myopia. Results: After the 1-year interval, the change of equivalent spherical refraction was(-0.67±1.11) D and(-0.76±1.11) D, respectively, in male and female participants, and their visual acuity decreased by 0.11±0.19 and 0.12±0.21, respectively. There were significant inter-group differences in the annual change of spherical power in different age groups (χ²=276.23, P<0.001). The naked eye visual acuity reduction was greatest in the 10-year-old students. The incidence of myopia was 42.2% (95% confidence intervals of 41.47% to 42.93%) during the 1-year follow-up period. The incidence of myopia was highest at the age of 14 (52.0% in males and 54.2% in females) and lowest at the age of 6 (31.0% in males and 33.1% in females). Conclusions: The 1-year follow-up revealed an obvious myopic shift in the refractive status of school students in Zhuozhou, with their naked eye visual acuity decreased. The incidence of myopia was higher in females than that in males.

Association of sedentary behaviors with visual acuity among primary school students: a cohort study

Objective To examine the association of sedentary behaviors with visual acuity among primary school children, and to provide a reference basis for the prevention and control of poor vision. Methods Using stratified random cluster sampling method, a total of 4 969 students in grade 1–4 were selected from 5 primary schools in Guangzhou in 2017, and then were followed up in 2019. A validated questionnaire was used to collect data on children’s sedentary behaviors, including doing homework, watching TV, playing computer/video games, and taking the bus/car between home and school. Visual acuity was measured in the baseline and the follow-up using a 5 m standard logarithmic visual acuity chart. Multiple linear regression and Logistic regression were conducted to analyze the relationship between sedentary behaviors and visual changes. Results The two-year cumulative incidence of poor vision was 48.74%. Homework time was inversely associated with visual acuity of left eye ( β = −0. 012, 95% CI = −0.023–−0.002). Homework time was positively correlated with poor vision ( OR = 1.16, 95% CI = 1.05–1.27). However, total sedentary time, screen time and bus/car time were not statistically associated with changes in visual acuity ( P>0.05). Conclusion Increased homework time was associated with poorer vision in primary school students. Interventions to reduce the academic burden should be taken. 【摘要】 目的 探究小学生静态行为与视力变化的关联性, 为学生视力不良防控工作提供参考依据。 方法 采用分层整群随机抽样的方法, 于 2017 年抽取广州市 5 所小学, 纳入一至四年级学生 4 969 名, 并于 2 年后进行随访。采用经信、效度检验的《广州市小学生体质健康监测系统问卷》收集小学生基线放学后做作业、看电视、用电脑/玩游戏、往返交通等静态行为时间。使用 5 m 标准对数视力表分别测量基线和随访的视力。分别采用多重线性回归和 Logistic 回归分析小学生静态行为与视力变化值以及视力不良的关联性。 结果 2 年期间, 一至四年级学生视力不良的累积发病率为 48.74%。放学后做作业时间与左眼视力变化值呈负相关 ( β = −0.012, 95% CI = −0.023~−0.002)。放学后做作业时长与视力不良的发生正性相关 ( OR = 1.16, 95% CI =1.05~1.27)。静态行为总时长、视屏时间、往返交通时间与视力变化相关均无统计学意义 ( P 值均>0.05)。 结论 静态行为中的放学后做作业时间增加与小学生视力降低相关, 合理减轻课业负担有利于视力保护。

A comparison of visual acuity measured by ETDRS chart and Standard Logarithmic Visual Acuity chart among outpatients

To compare the results of visual acuity (VA) measured by Early Treatment Diabetic Retinopathy Study (ETDRS) chart, 5 m Standard Logarithm Visual Acuity (5SL) chart, and 2.5 m Standard Logarithm Visual Acuity (2.5SL) chart in outpatients of age 12-80y. Each patient (totally 2000 outpatients) had both eyes tested with ETDRS chart at 4 m, 5SL chart at 5 m, and 2.5SL chart at 2.5 m in random order. The VA values of outpatients were categorized by ages. VA values were expressed by logMAR recording method. The mean VA results of ETDRS charts, 5SL, and 2.5SL chart were 0.52±0.28, 0.50±0.30, and 0.46±0.28 logMAR, respectively. There was a statistically significant difference in the three eye charts in the whole group (P<0.001). For all subjects, the correlation of VA tested with three charts was statistically significant (Spearman correlation coefficient=0.944, 0.937, 0.946, all P<0.001). Bland-Altman analysis shows the 95% limits of agreement between the 5SL and 2.5SL chart were -0.182 to 0.210, -0.139 to 0.251, and -0.151 to 0.235 logMAR, respectively). The agreement between the three eye charts is not high. The VA measured by 5SL chart is slightly better than that by ETDRS chart and 5SL chart would be a suitable alternative when ETDRS chart are not available in the clinical situation. The VA measured by 2.5SL chart is about 0.5 line better than VA tested with ETDRS chart, which may overestimate VA.

Associations between Poor Vision, Vision-Related Behaviors and Mathematics Achievement in Chinese Students from the CNAEQ-PEH 2015.

Purpose: Poor vision is prevalent in school-aged students, especially in East Asia. This can not only cause irreversibly physical health impairments like glaucoma and cataracts, but also the loss of individual education and employment opportunities and deterioration of the quality of life. The present study aims to investigate the associations between poor vision, vision-related risk behaviors, and mathematics achievement in youth from China. Methods: The present study included a total of 106,192 Grade 4 students and 70,236 Grade 8 students from the China National Assessment of Educational Quality-Physical Education & Health 2015 (CNAEQ-PEH 2015). We conducted a standard logarithmic visual acuity scale for vision screening, a self-reported questionnaire for vision-related risk behavior and a standardized mathematics assessment for mathematics performance. Poor vision is defined as the visual acuity below 5.0 by using the standard logarithmic visual acuity chart. Linear regression was conducted. Results: The prevalence rate of poor vision in China was 37.1% in Grade 4 and 66.2% in Grade 8 in 2015. Students who had poor vision were more likely to have better mathematics achievement than those with normal vision. Reading in bed, insufficient sleep, and screen time during weekdays and weekends were associated with higher odds of poor vision. Conclusions: Poor vision was positively associated with mathematics academic achievements, while vision-related risk behaviors such as screen time, homework time and reading in bed were associated with a high prevalence of poor vision in compulsory education cycle students.

Prenatal and neonatal factors for the development of childhood visual impairment in primary and middle school students: a cross-sectional survey in Guangzhou, China

ObjectivesIn this cross-sectional survey, we sought to determine the prevalence of and the influence of prenatal and neonatal factors on childhood visual impairment without correction (VIUC) in a paediatric population...

Poor eyesight in primary and middle school students in Beijing during 2010–2016

Objective To understand the prevalence and trend of the poor eyesight in primary and middle school students in Beijing, and to provide theoretical basis for eyesight protection and myopia prevention and control. Methods According to “Technical Standard for Student Health Inspection” (GB/T 26343–2010), students were examined with a standard logarithmic visual acuity E chart for naked eye vision. Results The prevalence of poor eyesight among primary and middle school students in 2010-2016 was 63.0%, 62.1%, 62.9%, 60.7%, 59.2% and 58.6% respectively, decreased by 7.0% in 6 years, primary school students dropped by 9.7%, and junior school students, senior high school students and vocational high school students increased by 5.5%, 3.3% and 14.1% respectively. Urban and suburban areas (61.2%, 54.3%) decreased by 9.6% and 2.9% respectively. Regardless of boys and girls, urban and suburb, between 2010 and 2016, the overall composition ratio of students in each school segment was expressed as primary school > junior school > senior high school students > vocational high school, and vocational high school students accounted for the minimum; the overall composition ratio of primary school has become more and more large. Conclusion Eyesight protection and myopia prevention among primary and middle school students in Beijing is still challenging. All departments should take active and effective measures to control the newly onset and progression of low vision and improve eyesight. 【摘要】 目的 了解北京市中小学生视力不良检出率及变化趋势, 为学生视力保护及近视防控提供参考依据。 方法 按照《学生健康检査技术规范》 (GB/T 26343—2010), 采用标准对数视力表对北京市全体中小学生进行裸眼远视力检査。 结果 2010—2016 年北京市中小学生视力不良检出率分别为 63.0%, 62.1%, 62.9%, 60.7%, 59.2% 和 58.6%, 6 年间下降了 7.0%。2015—2016 年小学生、初中生、普通髙中生、职业髙中生视力不良检出率分别为 45.5%, 78.4%, 89.4%和74.5%, 较 2010—2011 年小学生下降了 9.7%, 初中生、普通髙中生和职业髙中生分别增长了 5.5%, 3.3% 和 14.1%; 2015—2016 年, 城 区、郊区学生视力不良检出率分别为 61.2% 和 54.3%, 较 2010—2011 年分别下降了 9.6% 和 2.9%。不论男生、女生, 城区、 郊区, 2010—2016 年, 每年各学段学生总体构成比均表现为小学>初中>普通髙中>职业髙中, 职业髙中学生占比最小; 随着 年份的增加, 小学的构成比增大。 结论 北京市中小学生视力不良防控工作任务艰巨。各部门应采取积极有效的措施, 控 制视力不良新发和加重, 提髙中小学生视力健康水平。

Clinical study of modified Xuefu-Zhuyu decoction combined with conventional western medicine in the treatment of nonarteritic anterior ischemic optic neuropathy

Objective To evaluate the efficacy of modified Xuefu-Zhuyu decoction in the treatment of nonarteritic anterior ischemic optic neuropathy (NAION). Methods A total of 87 patients with NAION who met the inclusion criteria were divided into control group (43 cases) and study group (44 cases) by the random number table method. The control group was given the routine treatment combined with compound anisodine injection, while the study group was treated with routine treatment combined with modified Xuefu-Zhuyu decoction. Both groups were treated for 28 days. The standard logarithmic visual acuity chart was used to detect and record the best corrected visual acuity. The Visual field photosensitivity and visual field defect was recorded by visual field program(Oc-topus-101). The systolic peak blood flow velocity (PSV), end diastolic velocity (EDV), resistance index (RI) of the posterior ciliary short artery were measured by color Doppler ultrasound. The clinical effect was evaluated. Results The total effective rate was 97.7% (43/44) in the study group and 76.7% (33/43) in the control group. There were significant differences between the two groups (χ2=8.669, P=0.003). After treatment, the best corrected visual acuity (0.85 ± 0.21 vs. 0.72 ± 0.32 , t=2.245), visual field photosensitivity (18.71 ± 4.79 φ/db vs. 16.32 ± 5.22 φ/db, t=2.226) in the study group was significantly higher than those in the control group (P<0.05); the visual field defect (6.06 ± 1.52 φ/db vs. 8.13 ± 2.43 φ/db, t=4.775) in the study group was significantly lower than that of the control group (P<0.05); the PSV (10.03 ± 1.79 cm/s vs. 8.85 ± 1.88 cm/s, t=2.999), EDV (3.06 ± 0.37 cm/s vs. 2.67 ± 0.31 cm/s, t=5.323) in the study group was significantly higher than those of the control group (P<0.05), RI (0.61 ± 0.08 vs. 0.69 ± 0.09, t=4.385) in the study group was significantly lower than that of control group (P<0.05). Conclusions The modified Xuefu-Zhuyu decoction combined with conventional medicine can effectively improve the hemodynamics and visual function of posterior ciliary short artery in NAION patients and improve the clinical efficacy. Key words: Optic neuropathy, ischemic; Vision disorders; Xue Fu Zhu Yu Tang; Visual fields; Hemorheology; Integrated Chinese traditional and western medicine therapy

Using Decision Curve Analysis to Evaluate Common Strategies for Myopia Screening in School-Aged Children

ABSTRACTPurpose: To evaluate common strategies for screening myopia.Methods: A total of 2,248 children aged 6 to 12 years from five randomly selected primary schools were included for the screening. Enrolled study participants underwent distant uncorrected visual acuity (UCVA, Standard Logarithmic Visual Acuity E Chart) and non-cycloplegic auto-refraction (NCAR, Topcon KR-8800). Among them, 1,639 children (72.9%) accepted cycloplegic auto-refraction. Taking rejection of cycloplegia into account, receiver operating characteristic curves were drawn to compare the accuracies of the four strategies (I, Cycloplegic auto-refraction; II, NCAR; III, UCVA; IV, Combination of UCVA and NCAR). Decision curve analysis (DCA) was used to compare net benefits. Tenfold cross-validation was used for statistical analyses.Results: For myopia (spherical equivalent refraction, SE ≤ −0.5D) screening, the mean sensitivities were 73.79% (SD: 5.40%), 85.57% (6.84%), 59.71% (13.49%), and 85.06% (6.68%) for Strategy I to IV; with mean specificities of 100% (0%), 87.43% (4.27%), 89.74% (10.25%), and 88.65% (5.07%), respectively. For screening early myopia (SE ≤ −0.5D and ≥−1.0D), the mean sensitivities were 73.44% (7.69%), 82.39% (5.32%), 54.27% (14.58%), and 81.76% (9.60%) for Strategy I to IV; with mean specificities of 100% (0%), 79.13% (4.86%), 85.48% (9.86%), and 81.17% (4.16%). Based on DCA, the net benefits of Strategy IV were the highest, with the probability thresholds ranging from 12% to 50%, after adjusting the TestHarms. For early myopia, the net benefits of Strategy IV were the highest with the probability threshold ranging from 5% to 34%.Conclusion: Combination of UCVA and NCAR produced the highest net benefits for myopia screening.

Development of Corneal Astigmatism (CA) according to Axial Length/Corneal Radius (AL/CR) Ratio in a One-Year Follow-Up of Children in Beijing, China.

Purpose The correlations between the axial length-to-corneal radius (AL/CR) ratio and corneal astigmatism (CA) were studied by prospectively analyzing and comparing survey data from school children in the Beijing urban area from 2014 to 2015. Methods In this longitudinal study, a total of 2,970 students were enrolled in 2014, and 2,179 students were enrolled in 2015. The students were in grades 1 and 4 of primary schools located in the Yangfangdian district of Beijing. The students were examined using the standard logarithmic visual acuity chart for uncorrected visual acuity (UCVA) and IOLMaster for ocular components. Results From 2014 to 2015, the students from grades 1 and 4 had significantly worse UCVA results, longer axial lengths (AL), and greater AL/CRs (p < 0.001). The boys had a longer AL and corneal radius (CR) than the girls (p < 0.001). A significantly higher rate of increased CA was observed for the students with increased AL/CR than for those with decreased or unchanged ratios (AL/CR for grade 1, X2 = 12.304, p=0.001; for grade 4, X2 = 29.044, p < 0.001). In addition, with increased AL/CR over one year, the CA value of the students in grades 1 and 4 became significantly larger (grade 1, p=0.001; grade 4, p < 0.001); moreover, the UCVA became worse (p < 0.001). Conclusions We found that UCVA and AL growth were affected by aging. An increase in the AL/CR ratio is a risk factor for the progression of corneal astigmatism for school children.

Association between time spent on physical exercise, sleep, homework and suspected myopia among students

To investigate the prevalence of suspected myopia among students and to examine the relationship between time spent on physical exercise, sleep, homework and suspected myopia. A total of 8 030 primary and secondary school students from 4(th) to 12(th) grades were selected from the National Student Constitution and Health Survey (NSCHS) in Anhui province in 2014. Time spent on exercise, sleep and homework per day were collected using a self-administrated questionnaire. Visual acuity was examined using the Standard Logarithmic Visual Acuity Chart. The overall prevalence of suspected myopia was 69.03%. Prevalence rates of suspected myopia appeared higher in girls, in urban students, with the highest in the 16 to 18 year-old groups. RESULTS from the multiple logistic regression analysis showed that the amount of time spent on physical exercise, sleep and homework per day were all significantly associated with suspected myopia. Suspected myopia was associated with longer time on physical exercise among students aged 8 to 12 years (OR=0.80, 95%CI: 0.64-0.99), and longer sleep time among students in the age groups of 13 to 15 years and 16 to 18 years (OR=0.73, 95% CI: 0.56-0.94;OR=0.38, 95% CI: 0.21-0.68, respectively). Longer time spent on homework significantly increased the risk of suspected myopia among students in the age groups of 8 to 12 years and 13 to 15 years (OR=1.41, 95%CI: 1.11-1.79; OR=1.74, 95% CI: 1.36-2.23, respectively). Suspected myopia appeared common among students. Comprehensive intervention programs focusing on sufficient physical exercise and sleep but less homework might help to prevent myopia among students at different ages.

Prevalence and Causes of Visual Impairment and Blindness in Shanxi Province, China

Purpose: To estimate the prevalence and causes of visual impairment and blindness in Shanxi Province, China.Methods: Data were obtained from the Second National Sampling Survey of Disability conducted in 2006. Blindness and visual impairment were defined as best corrected visual acuity <3/60 and <6/18, respectively, in the better-seeing eye. Standardized ophthalmologic examinations were administered to participants aged 0–80 years in 2006. Visual acuity (VA) was measured using a Standard Logarithmic Visual Acuity E chart (Snellen) for subjects aged 7 years and older. Participants younger than 7 years were examined using special experiments or the Childhood Graphical Visual Chart.Results: The prevalence of visual impairment and blindness in Shanxi was estimated to be 0.6% (466/75,016) among persons up to 80 years old. The prevalence in rural areas (0.7%; 351/48,137) was significantly higher than that in urban areas (0.4%; 115/26,879) and was higher in females (0.8%; 298/36,933) than in males (0.4%; 168/38,083). The most common cause of visual impairment and blindness was cataract (44.9%), followed by retinopathy and choroidopathy (12.5%), hereditary and developmental disorders (10.3%), corneal disease (5.2%), and refractive error (4.9%).Conclusion: Prevalences of visual impairment and blindness in women and in rural areas were higher than in men and urban areas, and increased with age. Cataract was the most prevalent cause of visual impairment and blindness. Based on the findings from this study, we suggest that provision of support and welfare services should be organized.

Evaluation of transcranial surgical decompression of the optic canal as a treatment option for traumatic optic neuropathy

PurposeTraumatic optic neuropathy (TON) is a serious complication of head trauma, with the incidence rate ranging from 0.5% to 5%. The two treatment options widely practiced for TON are: (i) high-dose corticosteroid therapy and (ii) surgical decompression. However, till date, there is no consensus on the treatment protocol. This study aimed to evaluate the therapeutic efficacy of transcranial decompression of optic canal in TON patients. MethodsA total of 39 patients with visual loss resulting from TON between January 2005 and June 2013 were retrospectively reviewed for preoperative vision, preoperative image, visual evoked potential (VEP), surgical approach, postoperative visual acuity, complications, and follow-up results. ResultsAll these patients underwent transcranial decompression of optic canal. During the three-month follow-up period, among the 39 patients, 21 showed an improvement in their eyesight, 6 recovered to standard logarithmic visual acuity chart “visible,” 10 could count fingers, 2 could see hand movement, and 3 regained light sensation. ConclusionVisual evoked potential could be used as an important preoperative and prognostic evaluation parameter for TON patients. Once TON was diagnosed, surgery is a promising therapeutic option, especially when a VEP wave is detected, irrespective of the HRCT scan findings. Operative time between trauma and operation is not necessary reference to assess the therapeutic effect of surgical decompression. The poor results of this procedure may be related to the severity of optic nerve injury. The patient's age is an important factor affecting the surgical outcomes.

Association between elevated light levels in classrooms and change in vision acuity among elementary and secondary students

To explore the association between elevated light levels in classrooms and change in vision acuity among elementary and secondary students. A total of 4 elementary (grade 1-5) and secondary (grade 7-8) schools in urban and rural areas in Sujiatun, Shenyang, China were selected by cluster sampling as experimental schools, and lighting systems have been rebuilt to improve the ambient light levels in 56 classrooms in November 2012. The control schools were chosen for the comparable academic burden and adjacent location to experimental schools, 4 schools in all. Cluster sampling of all students in the selected schools as the subjects was carried out. A total of 2 092 students were chosen as experimental group and 1 595 students were in the control group. The luxmeter was used to measure illuminance of classrooms in two groups at baseline, and intervention for 1 month, respectively.Students in both groups were underwent 3 times for vision acuity examination by standard logarithmic visual acuity chart at baseline, intervention for 6 month and intervention for 1 year, respectively. The light levels of desk and blackboard in two groups were compared by Wilcoxon test. Multivariate analysis of covariance with repeated measures was performed to assess three vision acuity results between groups. After intervention, the average illuminance of desk (117.5 vs 532.5 lx, Z = -5.38, P < 0.001) and blackboard (75.6 vs 423.5 lx, Z = -5.38, P < 0.001) and uniformity of desk (Z = -4.28, P < 0.001) with new lighting were improved significantly than that with old lighting, however the uniformity of blackboard was lower than baseline significantly (0.64 vs 0.70, Z = -2.34, P = 0.019). The average scores of vision acuity in students at baseline, intervention for 6 month and intervention for 1 year were 4.87 ± 0.23, 4.84 ± 0.25 and 4.85 ± 0.23 in experimental group, and 4.88 ± 0.22, 4.84 ± 0.25 and 4.81 ± 0.27 in control group, respectively. The significant differences between groups were found and F values were 1.41, 0.13, 19.99, P values were 0.235,0.724, <0.001. At last the average vision acuity in experimental group were significantly better than that in control group either among elementary (4.90 ± 0.20) vs (4.87 ± 0.21) score, F = 13.61, P < 0.001 or secondary students (4.73 ± 0.28) vs (4.68 ± 0.32) score, F = 14.25, P < 0.001. Visual acuity loss could be decreased in students with elevated light levels which may slow the response to myopiagenic stimuli for eyes, therefore the ambient light levels of blackboard and desk in classroom should be improved.