Prevalence Of High Myopia Research Articles

Progression of Myopia in School-Aged Children After COVID-19 Home Confinement

Time spent in outdoor activities has decreased owing to home confinement for the coronavirus disease 2019 (COVID-19) pandemic. Concerns have been raised about whether home confinement may have worsened the burden of myopia owing to substantially decreased time spent outdoors and increased screen time at home. To investigate the refractive changes and prevalence of myopia in school-aged children during the COVID-19 home confinement. A prospective cross-sectional study using school-based photoscreenings in 123 535 children aged 6 to 13 years from 10 elementary schools in Feicheng, China, was conducted. The study was performed during 6 consecutive years (2015-2020). Data were analyzed in July 2020. Noncycloplegic photorefraction was examined using a photoscreener device. The spherical equivalent refraction was recorded for each child and the prevalence of myopia for each age group during each year was calculated. The mean spherical equivalent refraction and prevalence of myopia were compared between 2020 (after home confinement) and the previous 5 years for each age group. Of the 123 535 children included in the study, 64 335 (52.1%) were boys. A total of 194 904 test results (389 808 eyes) were included in the analysis. A substantial myopic shift (approximately -0.3 diopters [D]) was found in the 2020 school-based photoscreenings compared with previous years (2015-2019) for younger children aged 6 (-0.32 D), 7 (-0.28 D), and 8 (-0.29 D) years. The prevalence of myopia in the 2020 photoscreenings was higher than the highest prevalence of myopia within 2015-2019 for children aged 6 (21.5% vs 5.7%), 7 (26.2% vs 16.2%), and 8 (37.2% vs 27.7%) years. The differences in spherical equivalent refraction and the prevalence of myopia between 2020 and previous years were minimal in children aged 9 to 13 years. Home confinement during the COVID-19 pandemic appeared to be associated with a significant myopic shift for children aged 6 to 8 years according to 2020 school-based photoscreenings. However, numerous limitations warrant caution in the interpretation of these associations, including use of noncycloplegic refractions and lack of orthokeratology history or ocular biometry data. Younger children's refractive status may be more sensitive to environmental changes than older ages, given the younger children are in a critical period for the development of myopia.

Choroidal Thickness and Correlations with Intraocular Pressure and Spherical Equivalent in Young Myopic Eyes without Maculopathy

Background: Refractive error is one of the causes of visual impairment worldwide, among which myopia is the most common. Myopia is prevalent worldwide, particularly in East and Southeast Asia, which have myopia prevalence rates of approximately 80-90% and high myopia prevalence rates of 10-20% in young adults. High myopia is closely related to a variety of pathological changes and a higher risk of blinding complication. Purpose: To identify the distribution of choroidal thickness (CT) and to determine whether there are associations between subfoveal choroidal thickness (SFCT) and intraocular pressure (IOP) and spherical equivalent (SE) in young healthy myopes without maculopathy. Methods: A total of 116 young subjects without maculopathy were recruited in this study and underwent comprehensive ophthalmic examinations. Enhanced depth imaging spectral domain optical coherence tomography was performed for CT measurement and assessment. SFCT, as well as CT at 3 mm nasal, temporal, superior and inferior to fovea were measured. Univariable linear regression analysis and Multiple regression analysis were used to study the correlation between SFCT and spherical equivalent (SE) as well as IOP. To assess the CT at each location and explore it’s associated factors. Results: The SFCT of high myopes was notably thinner (197.00±35.21 µm) compared with mild myopes (287.05±68.31 µm) and moderate myopes (251.13±64.40µm). For all three groups, CT at 3 mm nasal was the thinnest (195.21±52.43µm, 168.43±59.24µm, 129.56±30.97µm, respectively.) Univariable linear regression analysis indicated that SFCT decreased by 15.49 µm per diopter in myopic refractive change (P <0.001, R2 = 0.146) and decreased by 17.87 µm per 1mmHg increase inintraocular pressure (IOP) (P < 0.001, R2 = 0.440). Multiple regression analysis indicated that there were significantly correlations between SFCT and spherical equivalent (SE) as well as IOP in mild myopes and moderate myopes, but not in high myopes. Conclusions: A significant difference of the CT distribution was found in the centre region among myopes. However, nasal choroid thinning was the most obvious in all myopia groups. SFCT was significantly correlated with IOP and SE in the myopic population. However, the same correlation was not observed in young highly myopic eyes.

Recent Epidemiology Study Data of Myopia.

Myopia, a pandemic refractive error, is affecting more and more people. The progression of myopia could cause numerously serious complications, even leading to blindness. This review summarizes the epidemiological studies on myopia after 2018 and analyzes the risk factors associated with myopia. The prevalence of myopia varies in different regions, age, and observation time. East Asia has been gripped by an unprecedented rise in myopia, and other parts of the world have also seen an increase. The prevalence of myopia in children continues to rise and aggravates with age. The prevalence of high myopia has also increased along with myopia. Racial dependence and family aggregation can be seen frequently in myopia patients. Increased outdoor activities are proven to be protective factors for myopia, as near-distance work and higher education levels affect in the opposite. The impact of gender or urbanization on myopia is controversial. The relationship between nutrition, digital screens, Kawasaki disease, pregnant women smoking during pregnancy, and myopia is still not clear for lack of sufficient evidence. Understanding the various factors that affect myopia helps to clarify the mechanism of myopia formation and also to formulate reasonable prevention and control measures of myopia to protect people's health, especially for adolescents.

Does Performing the Chinese Eye Exercises Help Protect Children's Vision? - New Evidence from Primary Schools in Rural Northwestern China.

BackgroundThe high prevalence of myopia among school-age children in China has raised serious concerns about protecting Chinese students’ vision. While the regular performance of the Chinese eye exercises has been adopted as a preventive approach in China since the mid-1960s, these exercises’ effectiveness at protecting students’ vision has remained largely unknown. This study attempts to provide new evidence of the impact of regularly performing the exercises on Chinese students’ visual outcomes, based on a large-scale dataset.MethodsA school-based survey was conducted among 9842 randomly selected students (fourth graders) from 252 primary schools in rural Northwestern China in 2012. To address potential estimation bias, we adopted both an instrumental variable (IV) approach and a bivariate-probit model to estimate the impacts on students’ visual acuity and the incidences of visual impairment and myopia.ResultsBoth IV and bivariate-probit estimates reveal a detrimental impact of regularly performing the Chinese eye exercises on students’ vision. Compared with students who did not regularly perform the exercises, those who did were 6.2 percentage points more likely to have impaired vision and 7.6 percentage points more likely to be myopic. The estimates are robust to different estimation strategies, various specifications, and the majority of subsamples.ConclusionUnder the assumption that the correct performance of the Chinese eye exercises would not undermine students’ vision, our findings suggest that the commonly-observed incorrect performance of these exercises among Chinese students imposes non-trivial threats to their vision health.

Prevalence and risk factor for refractive error in rural Chinese adults in Kailu, Inner Mongolia

To investigate the prevalence of refractive error in adults 40years of age and older in Kailu, Inner Mongolia. A population-based, cross-sectional study was conducted in Chinese adults. Spherical equivalent (S.E.) refractive error was determined from the right eye. Myopia and hyperopia were defined as a spherical equivalent (S.E.)<-0.5 dioptres (D) and >0.5D, respectively. Since the prevalence of high myopia will vary with the precise criterion chosen, the prevalence of this condition was calculated for thresholds of both <-5.0D and <6.0D. Astigmatism was defined as cylinder power >0.5D. Anisometropia was defined as a difference in S.E. between the two eyes >1.0D. The prevalence of myopia, high myopia (<-5.0D/<-6.0D) and hyperopia in Kailu adults was 60.3% (95%CI: 58.95-61.71), 5.5% (95%CI: 4.82-6.10) /4.0% (95%CI: 3.47-4.57) and 12.2% (95%CI: 11.26-13.11), respectively. The age- and gender-standardised prevalence of myopia, high myopia (-5.0D/-6.0D) and hyperopia were 62.5% (95%CI: 61.05-63.99), 5.0% (95%CI: 4.34-5.61) /3.5% (95%CI: 2.99-4.04) and 10.6% (95%CI: 9.71-11.49), respectively. 52.9% had refractive astigmatism >0.5D and 18.8% of subjects had clinically significant anisometropia. Age was significantly associated with hyperopia, high myopia, astigmatism and anisometropia. Myopia was more prevalent in females. Individuals with a higher educational level had a greater and lesser likelihood of myopia and astigmatism, respectively. Myopia affects around two-thirds of the rural Chinese population over 40years of age in Kailu. This high prevalence highlights that rural populations should be included in epidemiological studies of refractive error. Further investigations are needed to clarify the role of environmental factors in myopia development.

The Relation between High Myopia and Diabetic Retinopathy

Abstract Background: The prevalence of myopia is growing world-wide, and myopia is becoming a major epidemiological problem. A higher prevalence of myopia has been observed in people with diabetes compared with people without diabetes and poorer glycaemic control considered to be a risk factor. Aim of Study: To determine the relation between High Myopia and Diabetic Retinopathy and to detect whether high Myopes are self-protected against diabetic changes and diabetic retinopathy or not. Patients and Methods: The study included 140 eyes from 96 diabetic patients recruited from National Institute of Diabetes and Endocrinology in the Ophthalmic Clinic. They were classified according to the refractive status into four groups: Emmetropia (0.00 to –0.50 {DS}), Low Myopia (–0.50 DS to –3.0 DS), Moderate Myopia (3.00 DS to –5.00 DS) and High Myopia (more than –5.00 DS). High myopia (70 eyes of 41 patients), moderate myopia (10 eyes of 7 patients), low myopia (39 eyes of 29 patients) and emmetropia (21 eyes of 19 patients). Results: Total male patients represent 52.08% and females 46.92% in our study. There were statistically significant difference between groups as regard mean of refraction. Mean of refraction represented by Spherical equivalent among groups (Emmetrope, high myope, mild myope and moderate myope) was (2.08±0.495, 14.94±3.73, 3.23±0.642, 5.505±0.41) respectively. From our results the frequency of NPDR totally was 70 eyes (50%) and no DR was 70 eyes (50%). All high myopic eyes (70 eyes) showed no DR and all eyes of other groups which are totally (70 eyes) showed DR with its different grades. All high myopic eyes (70 eyes of 41 patients) had no DR in their fundus photograph while (low myopic, moderate myopic eyes and emmetropic eyes (39, 10, 21 eyes) respec-tively showed DR with its different grades: Low myopic eyes (39 eyes of 29 patients) showed moderate NPDR, the moderate myopic eyes (10 eyes of 7 patients) showed mild NPDR and the emmetropic eyes (21 eyes of 19 patients) showed severe NPDR. There were statistically significant difference between groups as regard severity of diabetes in which p-value <0.005. From our results as the degree of myopia increases the severity of DR decreases.Conclusion: There is a protective role for high myopia against DR.

Myopia prevalence in Denmark - a review of 140 years of myopia research.

To evaluate potential changes in myopia prevalence in Denmark by revising more than 100years of myopia research. A systematic literature search was performed in the PubMed, Embase and Cochrane Library databases. Only studies reporting a myopia prevalence in Denmark were included. Myopia was defined using the definition in individual references. We did not restrict inclusion of studies to specific methods of measuring or evaluating refraction. As refraction changes throughout life, information from available studies was divided in relevant age groups. Chi-squared test was used when analysing the effect of sex and education on myopia prevalence except when the expected values were beneath 5, where Fisher's exact test was used. To further compare the effect of sex, we calculated the odds ratio of being myopic for females compared to males. We identified 29 Danish studies reporting on prevalence of myopia. The studies were performed between year 1882 and 2018. We found no strong evidence of an increase in myopia prevalence in Denmark. Increasing age was associated with an increased myopia prevalence up to the age of 60years where after the prevalence decreased. Longer education and more intensive educational load were associated with myopia. Fourteen studies compared the prevalence of myopia between males and females and two of these studies found a significant higher prevalence in females. We evaluated nearly 140years of myopia research in Denmark and did not find a convincing change in prevalence of myopia which is in contrast to the high prevalence of myopia reported in some parts of the world and the expected rise in myopia as predicted by WHO.

Evolution of the Prevalence of Myopia among Taiwanese Schoolchildren: A Review of Survey Data from 1983 through 2017

The aim of this study was to evaluate the changes in the prevalence of myopia in Taiwanese schoolchildren over the past few decades and to analyze the risk factors for myopia. Analysis of 8 consecutive population-based myopia surveys conducted from 1983 through2017. An average of 8917 (5019-11 656) schoolchildren 3 to 18 years of age were selected using stratified systematic cluster sampling or by probability proportional to size sampling. All participants underwent complete ophthalmic evaluations. Three drops of 0.5% tropicamide were used to obtain the cycloplegic refractive status of each participant. Questionnaires were used to acquire participant data from the 1995, 2005, 2010, and 2016 surveys. Prevalence of myopia (spherical equivalence of ≤-0.25 diopter [D]) and high myopia (≤-6.0 D) was assessed. Multivariate analyses of risk factors were conducted. The prevalence of myopia among all age groups increased steadily. From 1983 through 2017, the weighted prevalence increased from 5.37% (95% confidence interval [CI], 3.50%-7.23%) to 25.41% (95% CI, 21.27%-29.55%) for 7-year-olds (P= 0.001 for trend) and from 30.66% (95% CI, 26.89%-34.43%) to 76.67% (95% CI, 72.94%-80.40%) for 12-year-olds (P= 0.001 for trend). The prevalence of high myopia also increased from 1.39% (95% CI, 0.43%-2.35%) to 4.26% (95% CI, 3.35%-5.17%) for 12-year-olds (P= 0.008 for trend) and from 4.37% (95% CI, 2.91%-5.82%) to 15.36% (95% CI, 13.78%-16.94%) for 15-year-olds (P= 0.039 for trend). In both the 2005 and 2016 survey samples, children who spent less than 180 minutes daily on near-work activities showed significantly lower risks for myopia developing (<60 minutes: odds ratio [OR], 0.48 and 0.56; 60-180 minutes: OR, 0.69 and 0.67). In the 2016 survey, spending more than 60 minutes daily on electronic devices was associated significantly with both myopia and high myopia (OR, 2.43 and 2.31). The prevalence of myopia among schoolchildren increased rapidly from 1983 through 2017 in Taiwan. The major risk factors are older age and time spent on near-work activities. Use of electronic devices increased the amount of time spent on near-work and may increase the risk of developing myopia.

Five-Year Incidence of Myopic Maculopathy in a General Japanese Population

Myopic maculopathy is a leading cause of irreversible visual impairment worldwide. Moreover, the burden of myopic maculopathy has been expected to increase owing to the rising prevalence of myopia globally. However, there is limited epidemiologic evidence regarding the incidence of and risk factors for myopic maculopathy. This study from Japan, with a relatively high prevalence of myopia, could provide valuable information related to these issues. To estimate the incidence of myopic maculopathy and its risk factors in Hisayama in southwestern Japan. A population-based prospective cohort study in a Japanese community in Hisayama, Japan. The study included a total of 2164 residents 40 years or older who had no myopic maculopathy at the baseline eye examination in 2012 and underwent follow-up eye examinations in 2017. Incidence of myopic maculopathy. The grades of myopic maculopathy were categorized based on the criteria of the Meta-analysis of Pathologic Myopia Study Group classification system. The mean (SD) age of the study participants was 62.4 (10.9) years, and the proportion of men was 42.5% (920 participants). In the follow-up examination in 2017, 24 patients developed myopic maculopathy. The 5-year cumulative incidence of myopic maculopathy was 1.1% (95% CI, 0.6-1.5) overall, 1.4% (95% CI, 0.6-2.2) for men, and 0.9% (95% CI, 0.4-1.4) for women. Multiple logistic regression analysis showed that older age (per 1 year; odds ratio [OR], 1.06; 95% CI, 1.01-1.11) and longer axial length (per 1 mm; OR, 2.94; 95% CI, 2.19-3.95) were associated with incident myopic maculopathy. Twenty-four study participants (1%) developed myopic maculopathy during the 5-year study period, which is much higher than the rate in a previous study on a Chinese population. We also confirmed that aging and longer axial length were independent and significant risk factors for myopic maculopathy. These findings should be reviewed among various populations in other parts of the world.

School-based epidemiology study of myopia in Tianjin, China

PurposeTo study the epidemiology of myopia in school-aged children in Tianjin and the relationship between visual acuity-based screening and refraction-based screening.MethodThis school-based prospective cohort study was performed on children from 42 elementary schools and 17 middle schools in Tianjin, China. Totally 14,551 children, ages ranging from 5 to 16 years, were included in this study. Uncorrected visual acuity (UCVA) was determined by logarithmic tumbling E chart. Non-cycloplegic photorefraction was examined by the Spot (v2.1.4) photoscreener. The relationship between the UCVA and refractive error was investigated for different age groups.ResultsThe overall prevalence of myopia at this school based screen is 78.2%, ranged from 10% at age of 5 to 95% at age of 16. The most dramatic increase in prevalence is from age of 6 (14.8%) to age of 7 (38.5%). The overall prevalence of high myopia is 2.5%. UCVA is found corresponding to spherical equivalent refraction (SER) in a manner of normal distribution and is significantly affected by age. When using UCVA to estimate the prevalence of myopia, the overall sensitivity and specificity are 0.824 and 0.820, respectively. Age-dependent optimal cutoff points and 95% confident intervals of such estimation are reported.ConclusionsMyopia is heavily affecting school-aged children in Tianjin, China. The refraction screening is preferable for myopia screening, whereas the UCVA screening results need to be interpreted in an age-dependent manner for myopia estimation.

Inheritance of Refractive Error in Millennials

Over the last decades, the prevalence of myopia has suddenly increased, and at this rate, half of the world’s population will be myopic by the year 2050. Contemporary behavioural and lifestyle circumstances, along with emergent technology, are thought to be responsible for this increase. Twin studies mostly reported a high heritability of refractive error across ethnicities. However, heritability is a population statistic and could vary as a result of changing environmental conditions. We studied the variance of refractive error in millennials with 100 twin pairs of university students in southeast Spain. The study population presented a high prevalence of myopia (77%). Statistical analysis showed the variance of refractive error in this group of young twins was mainly driven by the shared environment and, to a lesser extent, by additive genetic factors. We found an increase in myopia prevalence accompanied by a decrease in heritability in this sample of millennials in contrast with results from a previous generation group from the same ethnic origin.

Prevalence and associations of myopia in Hong Kong primary school students.

To examine the prevalence of myopia in primary school children in Hong Kong, and the risk factors for myopia development. A cross-sectional study. Subjective refraction and axial length were measured in all participants. Structured questionnaire was completed by the parents to assess risk factors of myopia. A total of 1396 children (491 boys) from Grade 1 to Grade 6 from 4 primary schools in Sham Shui Po district of Hong Kong participated. All participants underwent non-cycloplegic refraction. The overall prevalence of myopia (spherical equivalent, SE ≤ -0.5 diopter [D]) was 37.7%, which significantly increased with age, from 13.3% at grade 1 to 54.7% at grade 6. The prevalence of moderate myopia (-3.0D < SE < -6.0D) increased from 1.6% at grade 1 to 18.2% at grade 6 and the prevalence of high myopia (SE < = -6.0 D and/or AL ≥ 26.5mm) increased from 0.94% (7/747) in grade 1-3 students to 1.85% (12/649) in grade 4-6 students. Among the students with myopia, only 23.6% of the parents knew their children had refractive errors and only 19.8% of the children wore glasses. Multivariate logistic regression analysis showed myopia development was significantly associated with older age (OR = 1.36, P = 0.008), better academicranking in classin the preceding semester (OR = 1.01, P = 0.02) and absence of routine eye check (OR = 2.70, P = 0.001). The prevalence of myopia in primary school students in Hong Kong is high. There is a low level of awareness of refractive errors among parents, and high proportion of under-correction, resulting in suboptimal vision.

Refractive status and prevalence of myopia among Chinese primary school students

BackgroundThe aim of this study was to investigate the prevalence of myopia in key (university‐oriented) and non‐key elementary schools in China using a traditional and a new criterion for myopia diagnosis in an epidemiological study.MethodsThis school‐based, cross‐sectional study examined students from four key schools and seven non‐key schools. Non‐cycloplegic autorefraction and visual acuity (VA) were performed on each student. Myopia was defined as a spherical equivalent (SE) refractive error not better than −1.00 D. A questionnaire was also administered.ResultsOf the 13,220 students examined, 6,546 (49.5 per cent) had myopia using the criterion of SE not better than −1.00-D. However, 2,246 (34.3 per cent) of these myopes had VA ≥ 0 logMAR in both eyes, indicating they were not functioning as myopes. Thus, a second myopia criterion was adopted: SE refractive error not better than −1.00 D + uncorrected VA ≥ 0 logMAR in at least one eye. By this definition, only 32.5 per cent of the overall sample had myopia. Students in key schools had a higher prevalence of myopia than those in non‐key schools (53.8 per cent versus 44.7 per cent) by the initial criterion. By the new criterion, the prevalence of myopia was 41.2 per cent versus 22.7 per cent. Myopia was equal in grade 1 of both school types, but accelerated faster in key schools, where there was a much higher prevalence of myopia by fourth grade, and continued up to 79.2 per cent prevalence by sixth grade based on SE refractive error not better than −1.00 D.ConclusionStudents in more competitive university‐oriented elementary schools developed myopia much faster than those in regular schools, although they started with the same level of myopia. Since one‐third of the ‘myopes’ had VA ≥ 0 logMAR in both eyes, they would not be prescribed a correction, or be clinically treated as myopes. A new criterion of SE refractive error not better than −1.00 D + uncorrected VA ≥ 0 logMAR in at least one eye was tested. This criterion is more clinically appropriate and could be used in future epidemiological studies.

PREVALENCE AND TIME TRENDS OF MYOPIA IN CHILDREN AND ADOLESCENTS IN CHINA: A Systemic Review and Meta-Analysis.

To estimate prevalence, associated factors, and time trends of myopia in Chinese children and adolescents. We searched PubMed, EMBASE, and Web of Science for studies examining the prevalence of myopia in children and adolescents aged 3 years to 19 years in China before October 2018. We pooled the prevalence and associated factors for myopia and estimated time trends. In 22 eligible studies including 192,569 individuals, the pooled prevalence (95% confidence interval [CI]) of myopia and high myopia in the study period from 1998 to 2016 was 37.7% (95% CI: 23.5-52.0%) and 3.1% (95% CI: 1.2-5.0%), respectively, with higher odds for girls than boys (myopia: odds ratio: 1.29; 95% CI: 1.14-1.46; P < 0.001; high myopia: odds ratio: 1.37; 95% CI: 1.05-1.78; P = 0.02) and with higher prevalences for urban areas than rural regions (myopia: 48.8% [95% CI: 32.3-65.3] vs. 31.9% [95% CI: 20.4-43.3; P < 0.001]). The pooled prevalence of myopia and high myopia increased from 4.7% (95% CI: 2.5-6.9) and 0.2% (95% CI: 0.0-0.5), respectively, in <7-years-olds to 56.2% (95% CI: 29.8-82.5) and 15.1% (95% CI: 6.4-23.8), respectively, in 16- to 18-year-olds. Myopic refractive error increased with older age (P < 0.001), female gender (P < 0.001), and study year (P = 0.003). Studies performed after 2013 showed a prevalence of myopia and high myopia in the 16- to 18-year-olds of 84.8% (95% CI: 84.4-85.2%) and 19.3% (95% CI: 18.6-20.2%), respectively. Assuming a further linear relationship with the study year, myopia prevalence in 2050 among children and adolescents aged 3 years to 19 years would be estimated to be about 84%. The marked rise in high myopia prevalence among adolescents in China may be of importance for high myopia as risk factor for irreversible vision loss in Chinese adults in the future.

Risk Factors and Behaviours of Schoolchildren with Myopia in Taiwan.

Importance: Because of the high prevalence of myopia in Taiwan, understanding the risk factors for its development and progression is important to public health. Background: This study investigated the risk factors for myopia and their influence on the progression of myopia in schoolchildren in Taiwan. Design: Patients’ clinical records were obtained retrospectively from ophthalmologists. Questionnaires were given to collect demographic information, family background, hours spent on daily activities, myopia progression, and treatment methods. Participants: From a regional medical hospital in northern Taiwan, 522 schoolchildren with myopia participated in the study. Written informed consent was obtained from participants of legal age or the parents or legal guardians of younger children. Methods: Multivariable regression analyses were performed. Myopia measured in cycloplegic spherical equivalent (SE) was analysed, controlling for patients’ family and demographic information as well as their daily activity behaviours. Main Outcome Results: Children with high myopic parents were more myopic. Earlier onset age of myopia was associated with a higher level of myopia and greater annual myopic progression. Children reporting longer time usage of electronic devices had greater progression of myopia. Boys tended to be more myopic than girls. Lower levels of myopia were associated with more outdoor activities, and better vision care knowledge in children and parents. Conclusions and Relevance: In addition to genetics, education and environment can influence the development of myopia. Health policies for schoolchildren should promote protective activities and vision care knowledge at a young age, to protect the eyesight of schoolchildren.

Thirty-five-year trend in the prevalence of refractive error in Austrian conscripts based on 1.5 million participants

BackgroundTo quantify the current burden of myopia and hyperopia in Austrian young men and the time trend of myopia in the past 35 years by individual and social correlates.MethodWe included...

High prevalence of myopia in children and their parents in Hong Kong Chinese Population: the Hong Kong Children Eye Study.

To determine the myopia prevalence in Hong Kong Chinese children and their parents. It was a population-based cross-sectional study. A total of 4257 children aged 6-8years, and 5880 parents were recruited in the Hong Kong Children Eye Study. Cycloplegic autorefraction was measured for children; and non-cycloplegic autorefraction for parents. Parental educational level, children's outdoor time, and near work were collected by validated questionnaires. In children aged 6-8years, 25.0% were myopic, and among them, 12.7% for the 6-year-olds, 24.4% for the 7-year-olds and 36.1% for the 8-year-old. About 0.7% of children aged 8years were high myopia. In all age groups, boys (their myopia rate: 13.9% at 6years, 26.7% at 7years, and 38.3% at 8years) were more myopic than girls (11.3% at 6years, 22.0% at 7years, 33.4% at 8years). Among parents, 72.2% were myopic (mother, 73.2%; father, 70.7%) and 13.5% high myopia (mother, 12.8%; father, 14.5%). It was observed that prevalence decreased with ages and increased with education level. There is a strikingly high prevalence of myopia in Hong Kong children aged 6-8, much higher than that of other regions of China. Of note, the prevalence of children was similar to that in 15years ago. Furthermore, the myopia prevalence of parents is high, and it had already increased in this cohort. Prevention of childhood myopia is important, likewise for visual complications from high myopia in adults.

Factors associated with myopia in Korean children: Korea National Health and nutrition examination survey 2016\u20132017 (KNHANES VII)

BackgroundTo evaluate the prevalence and risk factors associated with myopia and high myopia in children in South Korea.MethodsA total of 983 children 5–18 years of age who participated in the Korean National Health and Nutrition Examination Survey 2016–2017 (KNHANES VII), a nationwide population-based cross-sectional study, were evaluated. Myopia and high myopia were defined as a spherical equivalent (SE) ≤ − 0.5 diopters (D) and SE ≤ --6.0 D. The association between refractive errors and potential risk factors for myopia was analyzed.ResultsThe prevalence of myopia and high myopia was 65.4 and 6.9%, respectively. Older age and parental myopia were significantly associated with both myopia and high myopia, while higher body mass index (BMI) was associated with high myopia only. Although the proportion of subjects who spent more time on near work activities (≥4 h/day) was sequentially increased with increased refractive error, this tendency was not statistically significant by multivariable logistic regression.ConclusionsKorean children had a high prevalence of myopia and high myopia. In this age group, the risk of myopia increased with aging and parental myopia. Higher BMI may be associated with high myopia.

Prevalence of myopia and vision impairment in school students in Eastern China

BackgroundPrevention of myopia has become a public health priority in China. This study is to investigate the prevalence of myopia and vision impairment, and their associated factors in school students in eastern China.MethodIn this cross-sectional school-based study of 4801 students from 16 schools ranging from kindergarten to high school, students underwent refraction using non-cycloplegic autorefractor and visual acuity testing using logMAR chart with tumbling E. Myopia was defined as spherical equivalent (SPHE) ≤ − 0.5 diopter (D) and uncorrected visual acuity (UCVA) 20/25 or worse. High myopia was defined as SPHE ≤ − 6.0 D and UCVA 20/25 or worse. Vision impairment was defined as UCVA 20/40 or worse. Logistic regression models were used to determine factors associated with myopia and vision impairment.ResultsAmong 4801 children (55% male) with mean age (standard deviation) 12.3 (3.8) years, 3030 (63.1, 95% CI: 61.7–64.5%) had myopia, 452 (9.4, 95% CI: 8.6–10.3%) had high myopia, and 2644 (55.1, 95% CI, 53.7–56.5%) had vision impairment. The prevalence rate of myopia increased with grade in a non-linear manner, 12% in kindergarten, 32% in grade 2, 69% in grade 5, and approximately 90% by grade 10 or above. The prevalence rate of high myopia was relatively low in grade 4 or below (< 1.5%), 4–7% in grade 5 to 7, 13–15% in grade 8–9, and > 20% in grade 10 to 12. The prevalence rate of vision impairment was 4% in kindergarten, 37% in elementary school, 77% in middle school and 87% in high school students. Higher grade (p < 0.0001), female (p < 0.0001) and higher school workload (p = 0.007) were independently associated with higher prevalence rates of myopia and vision impairment, while higher grade (p < 0.0001) and higher school workload (p < 0.0001) were independently associated with higher prevalence of high myopia.ConclusionPrevalence of myopia and vision impairment was high among Chinese school students and increased with grade in a non-linear manner, reaching alarming high in high school students accompanied by high prevalence of high myopia. Increasing study burden on school students at younger age plays an important role on the higher prevalence rate of myopia and vision impairment.

Study on Incidence and Progression of Refractive Errors in Medical Students.

To study the incidence and progression of refractive errors in medical students. This is a retrospective study including 200 medical students of our college during the period of July 2015 to June 2018. Examination included visual acuity testing using Snellens chart, slit lamp biomicroscopy, fund us examination with direct ophthalmoscope, indirect ophthalmoscope and refraction. Students were examined for refractive errors and findings compared with pre-admission data. Changes in spherical, cylindrical power analysed. Prevalence of Myopia increased from 40% to 48%. Incidence of new refractive errors in emmetropes was 8%. Myopic change found was -0.75D to -1.0D. Students in medical colleges have high prevalence of myopia, high incidence of adult onset myopia and statistically significant progression. Parental history, prolonged eye strain, excessive use of electronic gadgets, decreased outdoor activity and urban background had significant association with prevalence of myopia.