Prevalence and risk factors for astigmatism in 7 to 19-year-old students in Xinjiang, China: a cross-sectional study.

BACKGROUND: To investigate the prevalence and risk factors for astigmatism in 7-19-year-old students in Xinjiang, China. METHODS: A school-based, cross-sectional study was conducted on students who underwent refraction examination in Xinjiang, China, between May and December 2019. The prevalence of astigmatism was determined. Astigmatism was defined as cylinder power (C) ≤-0.75 D, undefined astigmatism as ≤-1.50 D, and high astigmatism as C ≤-3.00 D. Astigmatism types were: against-the-rule astigmatism (maximum refraction of the main meridian in 180° ± 30°), with-the-rule astigmatism (maximum refraction of the main meridian at 90°±30°), and oblique astigmatism (all other cases). RESULTS: Of the 71,838 students examined (51.0% boys, 7 - 19 years old), 25,945 (36.1%, 95%CI: 35.52-36.68%) had astigmatism and 1267 (1.8%, 95%CI: 1.07-2.53%) had high astigmatism. The prevalence of astigmatism was greater in Han individuals (39.6%) compared with the Hui (34.0%), Kazakh (34.0%), Kyrgyz (32.1%), and Uyghur (26.4%) populations. Among the 25,945 students with astigmatism, 19,947 had with-the-rule astigmatism (76.9%), 3405 had against-the-rule astigmatism (13.1%), and 2593 had oblique astigmatism (10.0%). Multivariable logistic regression analysis showed that ethnicity (Han individuals more susceptible), male gender, age, and refractive errors (myopia and hyperopia) were independently associated with astigmatism, high astigmatism, and with-the-rule astigmatism (all P < 0.05). CONCLUSIONS: The prevalence of astigmatism among children and adolescents in Xinjiang was 36.1%, including 1.8% of high astigmatism. In this population, astigmatism was mainly of the with-the-rule astigmatism type (76.9%). Han ethnicity, male gender, and myopia or hyperopia were independently associated with a high risk of astigmatism.

Artificial intelligence enhanced ophthalmological screening in children: insights from a cohort study in Lubelskie Voivodeship.

This study aims to investigate the prevalence of visual impairments, such as myopia, hyperopia, and astigmatism, among school-age children (7-9 years) in Lubelskie Voivodeship (Republic of Poland) and apply artificial intelligence (AI) in the detection of severe ocular diseases. A total of 1049 participants (1.7% of the total child population in the region) were examined through a combination of standardized visual acuity tests, autorefraction, and assessment of fundus images by a convolutional neural network (CNN) model. The results from this artificial intelligence (AI) model were juxtaposed with assessments conducted by two experienced ophthalmologists to gauge the model's accuracy. The results demonstrated myopia, hyperopia, and astigmatism prevalences of 3.7%, 16.9%, and 7.8%, respectively, with myopia showing a significant age-related increase and hyperopia decreasing with age. The AI model performance was evaluated using the Dice coefficient, reaching 93.3%, indicating that the CNN model was highly accurate. The study underscores the utility of AI in the early detection and diagnosis of severe ocular diseases, providing a foundation for future research to improve paediatric ophthalmic screening and treatment outcomes.

Prevalence, Associated Factors, and Inter-Eye Differences of Refractive Errors in a Population-Based Japanese Cohort: The Tohoku Medical Megabank Eye Study.

PURPOSE: To investigate the prevalence, associated factors, and inter-eye differences of myopia and astigmatism in an adult Japanese population-based cohort. METHODS: A total of 4282 participants from the Tohoku Medical Megabank Organization Eye Study (ToMMo Eye Study) underwent comprehensive ocular examinations as well as extensive physiological tests and a lifestyle questionnaire. The spherical equivalent (SE) and cylinder power were obtained as refractive parameters. The age- and gender-stratified prevalences of high myopia (SE < -5D), myopia (SE < -0.5D), hyperopia (SE > 0.5D), astigmatism (cylinder power < -0.5D), and anisometropia (SE difference >1D) were calculated. Multivariable analyses were performed to identify associated factors for refractive error (RE). Distribution and associated factors of the inter-eye difference in RE were also investigated. RESULTS: The age-adjusted prevalence of high myopia, myopia, hyperopia, astigmatism, and anisometropia was 15.9%, 63.5%, 14.7%, 51.1%, and 14.7%, respectively. Both myopia and high myopia were more prevalent in the younger age group, while astigmatism was more prevalent in the older age group. Age, education, blood pressure, intraocular pressure, and corneal thickness are significantly associated with myopic refraction. Age, gender, intraocular pressure, and corneal thickness are correlated with astigmatism. Older age was associated with against-the-rule astigmatism. Older age, myopia, and longer education showed a significant correlation with large inter-eye differences in SERE. CONCLUSIONS: This study demonstrated the high prevalence of myopia in young Japanese, which may be caused by a generational shift. This study also confirmed the influence of age and education on both the prevalence and inter-eye differences of RE.

Prevalence of refractive errors in population aged 50 years and over: The Gilan eye study.

PURPOSE: To describe the prevalence of refractive error (RE) and its association with other environmental and health factors among population aged ≥50 years who lived in Gilan, Iran in 2014. METHODS: In this population-based cross-sectional study, 3281 individuals aged ≥50 years living in Gilan for at least 6 months were enrolled. The prevalence of different types of REs including myopia (spherical equivalent (SE)≤-0.50D), high myopia (SE ≤ -6.00D), hyperopia (SE≥ + 0.50D), high hyperopia (SE≥ + 3.00D), astigmatism (cylinder < -0.50D) and high astigmatism (cylinder < -2.25D) were determined. Anisometropia was defined as the SE difference of ≥1.00D between the two eyes. Associated factors including age, body mass index (BMI) and education were also studied. RESULTS: 2587 eligible individuals (58% female subjects) with the mean age of 62.6 ± 8.8 years participated (87.6% response rate). The prevalence of myopia, hyperopia and astigmatism was 19.2%, 48.6% and 57.4%, respectively. 3.6% high hyperopia, 0.5% high myopia and 4.5% high astigmatism were identified. The positive simultaneous effects3 of older age (Odds Ratio (OR) = 3.14), nuclear (OR = 1.71) and posterior subcapsular (OR = 1.61) cataracts as well as the negative effects of higher levels of education (OR = 0.28) were obtained on myopia. Higher BMI was found as a risk factor for hyperopia (OR = 1.67), while older patients were less likely to be hyperopic (OR = 0.31). CONCLUSION: Higher incidence of myopia and astigmatism was found in patients aged over 70 years. It was also found that patients at older ages who suffered with cataracts were at a higher risk of myopia, while elderly people with greater BMI were at a higher risk of hyperopia.

Changes in ocular astigmatism with age: A longitudinal study.

PURPOSE: To investigate changes in astigmatism with age. Are changes from with-the-rule (WTR) in younger ages to against-the-rule (ATR) in older patients mediated through oblique astigmatic axes or spherical prescriptions, and at what ages do these changes occur? METHODS: Prescription data were gathered retrospectively from one optical practice belonging to a large multiple group in the UK. Longitudinal assessments were made of the changes in astigmatism for 326 patients (mean age at first prescription 46 years, range 28-69 years) and 640 eyes through their recorded prescription history (median 20 years of prescription data per participant, IQR 19-22 years, range 18-29 years). RESULTS: Changes in small degrees of astigmatism (0.25 or 0.50 DC) from WTR to ATR were more than three times more likely to pass through an oblique cylinder axis as through a spherical prescription (56 vs. 16, χ 1 2 = 22.2, p < 0.0001). For patients aged 28-40 years at their first recorded eye examination, 55% (92/167) of eyes had an onset of astigmatic changes at a mean of 44 years (SD 6.2) and 41% (68/167) of eyes had no change until after a mean of 54 years (SD 4.6). Compared with a measured prevalence of oblique astigmatism in the literature of 11%-19%, 36% (232/640) of the eyes in this study had an oblique cylinder prescribed at least once in their refraction history and of these oblique cylinders, 78% were transient in nature. CONCLUSIONS: The change in ocular astigmatism with age, from WTR to ATR, was more than three times more likely (56 vs. 16) to pass through oblique cylinder axes as through a spherical prescription. Changes in oblique astigmatism have been implicated in complaints with new spectacles, so given this prevalence of oblique cylinder axes (232/640, 36%), continuing professional development is needed regarding reconciling these oblique changes with previous prescriptions.

Refractive and corneal astigmatism in Chinese 4-15 years old children: prevalence and risk factors.

BACKGROUND: To investigate the prevalence and risk factors of refractive astigmatism (RA) and corneal astigmatism (CA) in preschool children and school-aged children in Shanghai, China. METHODS: In this school-based, cross-sectional study, 4-15 years old children across three learning stages of kindergarten, primary school, and junior high school underwent noncycloplegic autorefraction and completed comprehensive questionnaires involving time spent on daily homework and outdoor activities. Data from the right eyes were analysed. RESULTS: Overall, 7084 children (mean ± standard deviation (SD) of age: 8.08 ± 3.11 years) were included, and the prevalence rates of RA/CA ( ≤ - 1.0 D) in children were 15.8%/64% in kindergartens, 16.5%/65% in primary schools, and 32.8%/76.9% in junior high schools. The magnitude and prevalence of RA and CA all increased with age or with learning stage (all P < 0.001). The presence of RA was associated with more myopic spherical power (odds ratio (OR) 0.956, P = 0.021), junior high school (OR 1.973, P < 0.001), longer homework time on weekdays (OR 1.074, P = 0.029), and shorter outdoor activity time on weekends (odds ratio 0.929, P = 0.013). CONCLUSION: In the wide age range of 4 to 15 years, the magnitude and prevalence of RA and CA increased with the learning stage, and these increases mainly began at the primary school stage. Factors, including longer homework time and shorter outdoor time were correlated with the presence of RA.

Trends in the prevalence of common ocular conditions and comparison of ophthalmic outpatient utilisation related to these conditions in children with and without various types of disabilities: analysis of nationwide population-based data from Taiwan, 2014-2019.

OBJECTIVE: The study objectives were to investigate trends in the prevalence of common ocular conditions among children with and without disabilities; to compare the prevalence of these conditions in children with various disabilities; and to compare ophthalmic outpatient utilisation related to these ocular conditions in children with and without disabilities. DESIGN: Repeated cross-sectional nationwide population-based study. SETTING: Nationwide analysis in Taiwan based on National Health Insurance (NHI) claims data and the National Disability Registry, from 2014 to 2019. PARTICIPANTS: All children (aged under 18 years) with a disability in any given year between 2014 and 2019 were included in our analysis. All children with a disability (experimental group) were matched 1:1 with a child of the same age without a disability (control group). Data regarding the children's disability type and status and ocular conditions were obtained from the National Disability Registry and NHI database of Taiwan. OUTCOME MEASURES: (1) The prevalence of myopia, strabismus, astigmatism, amblyopia and hyperopia over time; (2) the prevalence of myopia, strabismus, astigmatism, amblyopia and hyperopia in children with various disabilities; and (3) the association between disability and the use of outpatient vision care. All outcome measures were assessed using data from 2014 to 2019. RESULTS: Among children with disability, the prevalence of myopia increased from 15.97% in 2014 to 18.07% in 2019. The prevalence of strabismus (2.06-3.90%), astigmatism (8.25-9.24%), amblyopia (4.13-4.95%) and hyperopia (3.36-4.58%) also increased over the study period in children with disabilities. The prevalence of strabismus, astigmatism, amblyopia and hyperopia was significantly higher in children with disabilities than in those without disabilities in all years. For example, in 2019, the prevalence values for strabismus, astigmatism, amblyopia and hyperopia were 3.90%, 9.24%, 4.95% and 4.58%, respectively, among children with disabilities, and 0.67%, 5.84%, 1.33% and 1.70%, respectively, for those without disabilities. The prevalence of these conditions varied considerably across disability types. For example, in 2019, the prevalence of strabismus was highest in children with visual disabilities (10.66%; p<0.001); these children also exhibited a high prevalence of amblyopia (24.34%; p<0.001). The prevalence of myopia was high in children with autism (24.77%), but the prevalence of other ocular conditions was not elevated in this group. Regression results indicated that for myopia, children with disability had 0.48 fewer outpatient clinic visits than those without disability (p<0.001). CONCLUSIONS: The prevalence of common ocular conditions and the corresponding vision care required vary across types of disabilities among children. Healthcare policies must account for children at high risk of various ocular conditions, including those with less common disabilities.

Bidirectional associations between hyperopia, myopia, astigmatism, and strabismus, and attention-deficit/hyperactivity disorder in children: a national population-based cohort study.

OBJECTIVES: The present study analyzed the reciprocal relationships between four common pediatric ophthalmic diseases (i.e., hyperopia, myopia, astigmatism, and strabismus) and attention-deficit/hyperactivity disorder (ADHD) in children. METHODS: This study enrolled 86,028 children with ADHD and 1,798,673 children without ADHD in the Taiwan Maternal and Child Health Database who were born at any time from 2004 to 2017. Cox proportional hazards regression models were used to estimate the bidirectional relationships of the four ophthalmic diseases with ADHD in children after adjusting for age, sex, and gestational age at birth. Survival curves for time-to-event variables were estimated using the Kaplan-Meier method, and the log-rank test was used to compare the curves. RESULTS: The results indicated that ADHD significantly predicted the occurrence of hyperopia, myopia, astigmatism, and strabismus. Furthermore, hyperopia, myopia, astigmatism, and strabismus significantly predicted the occurrence of ADHD. The time between enrollment and ADHD diagnosis was shorter for patients with ophthalmic diseases than for the control group, and the time between enrollment and ophthalmic disease diagnosis was also shorter for ADHD patients than for the control group. Sex differences were found in the associations between ADHD and ophthalmic diseases. CONCLUSION: Clinicians should monitor children with ADHD for hyperopia, myopia, astigmatism, and strabismus to ensure appropriate treatment, and vice versa.

A large-scale analysis of refractive errors in students attending public primary schools in Mexico.

A cross-sectional, retrospective study was conducted from September 2013 through July 2014 to determine the prevalence of refractive errors among students attending public primary schools in Mexico. Among 3,861,156 students at 14,566 public primary schools in all 32 states of Mexico, teachers identified reduced visual acuity in 1,253,589 (32.5%) using visual acuity measurement. Optometrists confirmed 391,498 [31.2%, mean (SD) age: 8.8 (1.9) years; 204,110 girls (52.9%)] had refractive errors using visual acuity measurement and noncycloplegic static retinoscopy. Among 288,537 (72.4%) of children with previous eyeglasses usage data reported, 241,505 (83.7%) had uncorrected refractive errors. Before prescription eyeglasses were provided, 281,891 students (72%) had logMAR visual acuity ≤ 0.2; eyeglasses corrected vision loss in 85.6% (n = 241,352) of them. Simple myopic astigmatism was the most frequent refractive error (25.7%, n = 100,545). Astigmatism > - 1.00 diopters was present in 54.6% of all students with ametropia. The anisometropia rate based on spherical equivalent difference between right and left eye ≥ 1.50 diopters was 3.9% (n = 15,402). Uncorrected refractive errors are an important issue in primary school students in Mexico. An updated study is needed to analyze the evolving trends over the past decade.

[Influence of tropical endemic limboconjunctivitis on the distribution of astigmatism in a black pediatric population: A hospital-based case-control study]. / Influence de la limbo-conjonctivite endémique des tropiques sur la distribution de l'astigmatisme dans une population d'enfants mélanodermes camerounais : étude hospitalière cas-témoins.

PURPOSE: To study the influence of tropical endemic limboconjunctivitis (TELC) on the distribution of astigmatism in a population of black children. PATIENTS AND METHODS: We matched two groups of 36 children between the ages of 3 and 15 by age and sex. Group 1 consisted of children with TELC, and group 2 was made up of controls. All underwent cycloplegic refraction. The studied variables were age, sex, type and stage of TELC, spherical equivalent, absolute cylinder value and clinical type of astigmatism. The odds ratio was used to quantify the link between TELC and astigmatism. We used the Chi2 test for the comparison of qualitative variables and the Student T test for the comparison of the means of quantitative variables. The threshold of significance of the differences was set at 0.05. RESULTS: Astigmatism was more common in children with TELC (61.97% vs. 37.5%), (OR=1.53; 95% CI 1.08-2.15; P=0.012). The history of TELC was associated with an increased risk of with-the-rule astigmatism (OR 1.91; 95%CI (1.23-2.97). CONCLUSION: Pediatric TELC is frequently associated with the with-the-rule astigmatism in our practice setting.

The association between time spent on screens and reading with myopia, premyopia and ocular biometric and anthropometric measures in 6- to 7-year-old schoolchildren in Ireland.

PURPOSE: More time spent on near tasks has consistently been associated with the promotion of myopia. The World Health Organization advises limiting daily screentime to less than 2 h for children aged five and over. This study explored the relationship between time spent on screens and reading/writing with refractive status, ocular biometric and anthropometric factors in 6- to 7-year-olds in Ireland. METHODS: Participants were 723 schoolchildren (377 boys [51.8%]), mean age 7.08 (0.45) years. The examination included cycloplegic autorefraction (1% cyclopentolate hydrochloride), ocular biometry (Zeiss IOLMaster), height (cm) and weight (kg). Screentime and reading/writing time were reported by parents/legal guardians by questionnaire. Myopia (≤-0.50D) and premyopia (>-0.50D ≤ 0.75D) risk assessments were performed using logistic regression, and multivariate linear regression was used to analyse continuous variables. RESULTS: Reported daily screentimes were 31% <1 h, 49.5% 1-2 h, 15.6% 2-4 h and 3.9% >4 h. Reading/writing times were 42.2% frequently, 48.0% infrequently and 9.8% seldom/never. Linear regression, controlling for age and ethnicity, revealed >2 h/day on screens was associated with a more myopic spherical equivalent [ß = -1.15 (95% confidence intervals {CIs}: 1.62-0.69, p < 0.001)], increased refractive astigmatism (ß = 0.29, CI: 0.06-0.51, p = 0.01), shorter corneal radius (ß = 0.12, CI: 0.02-0.22, p = 0.02), higher axial length/corneal radius (ß = 0.06, CI: 0.03-0.09, p < 0.001), heavier weight (ß = 1.60, CI: 0.76-2.45, p < 0.001) and higher body mass index (BMI) (ß = 1.10, CI: 0.28-1.12, p < 0.001). Logistic regression, controlling for age and ethnicity, revealed daily screentime >2 h was associated with myopia (OR = 10.9, CI: 4.4-27.2, p = 0.01) and premyopia (OR = 2.4, CI: 1.5-3.7, p < 0.001). Frequent reading/writing was associated with screentime ≤2 h/day (OR = 3.2, CI: 1.8-5.8, p < 0.001). CONCLUSION: Increased screentime was associated with a more myopic refraction, higher axial length/corneal radius ratio, increased odds of myopia, premyopia, higher degrees of astigmatism, increased weight, BMI and decreased reading/writing time. Dedicated education programmes promoting decreased screentime in children are vital to prevent myopia and support eye and general health.

Characteristics of full compensation and its association with total astigmatism: A cross-sectional study.

Objective: To evaluate the characteristics of full compensation and its association with the prevalence of total astigmatism (TA), and to analyze the effects of TA on uncorrected distance visual acuity (UDVA). Methods: With random cluster sampling based on a school-based cross-sectional design, children aged 4 to 18 years were recruited in September 2020, Shandong Province, China. TA, anterior corneal astigmatism (ACA), and ocular residual astigmatism (ORA) were converted to vectorial components (J0, J45), followed by an assessment of the compensatory effect of ACA by ORA. Astigmatism was defined as a cylinder that was better than or equal to 0.75 diopters (D). Logistic regression analysis was used to assess the related factors for children with full compensation, and the generalized linear model was used to assess the influence of TA on UDVA. Results: Out of 4,494 eligible children, data of 4,145 children (92.3%, 9.23 ± 3.15 years, 50.4% boys) were included in the statistical analysis. The prevalence of TA (27.9%) increased significantly with age (Ptrend < 0.001). The distribution of full compensation in J0 and J45 components were similar (22.1% and 25.6%, respectively), which decreased with age (Ptrend < 0.001). The closer the refractive status was to emmetropization, the higher the proportion of full compensation and the lower the prevalence of TA were. Shorter axial length (J0: Odds Ratio (OR) = 0.76, 95% confidence interval (CI): 0.61 to 0.94, P = 0.010), better UDVA (J0: OR = 0.37, 95% CI: 0.21 to 0.65, P < 0.001; J45: OR = 0.34, 95% CI: 0.20 to 0.59, P < 0.001), and longer average corneal curvature radius (J0: OR = 3.72, 95% CI: 2.18 to 6.34, P < 0.001; J45: OR = 2.82, 95% CI: 1.67 to 4.76, P < 0.001) were associated with full compensation. Higher TA was associated with a worse UDVA (ß = 0.03, 95% CI: 0.02 to 0.04, P < 0.001). Conclusions: The prevalence of TA gradually increased with age, and showed a U-shaped distribution with increased refraction. Full compensation was associated with smaller TA and better UDVA. This indicated that considering the compensatory effect of ORA is vital for astigmatism correction in clinical work, which may improve the visual quality.

Epidemiology and Burden of Astigmatism: A Systematic Literature Review.

SIGNIFICANCE: This is the first literature review to report the epidemiology, patient burden, and economic burden of astigmatism in the general adult population. The unmet needs of astigmatism patients with coexisting ocular conditions (cataract, glaucoma, dry eye, presbyopia, or macular degeneration) and risks associated with untreated astigmatism are also reviewed and reported. PURPOSE: This study aimed to identify, report, and summarize the published literature on epidemiology, patient burden, and economic burden of astigmatism using a systematic literature review. METHODS: MEDLINE, EMBASE, and Cochrane Library databases were searched (January 1996 to May 2021). Search results were limited to the English language. Proceedings (2018 to 2021) from ophthalmology congresses were searched along with gray literature using the Google Scholar platform. RESULTS: The literature search yielded 6804 citations, of which 125 met the inclusion criteria (epidemiology, 68; patient burden, 60; economic burden, 6). Astigmatism prevalence in the general population varied from 8 to 62%, with higher rates in individuals 70 years or older. The prevalence of with-the-rule astigmatism was higher in individuals 40 years or younger, whereas rates of against-the-rule and oblique astigmatism increased with age. Astigmatic patients experienced decreased vision quality, increased glare (53 to 77%), haloes (28 to 80%), night-time driving difficulties (66%), falls, and spectacle dependence (45 to 85%). Astigmatic patients performed vision-related tasks slower (1 D, 9% slower; 2 D, 29% slower) and made more errors (1 D, 38% more errors; 2 D, 370% more errors) compared with fully corrected individuals. In cataract patients with astigmatism, the annual mean per-patient productivity loss costs ranged from €55 ($71) to €84 ($108), and mean informal care costs ranged from €30 ($39) to €55 ($71) with a mean of 2.3 to 4.1 hours spent on informal care. CONCLUSIONS: Uncorrected astigmatism decreases patients' vision-related quality of life, decreases productivity among working-age adults, and poses an economic burden on patients and their families.

Distribution of Astigmatism among School Children Who Fail Vision Screening in South India.

PURPOSE: The purpose of this study is to report the distribution of astigmatism among school children in South India. METHODS: The study was conducted as part of a national school eye screening project named 'Refractive Error Among Children' (REACH) between 6 and 17 years of age. Children underwent presenting visual acuity screening, external eye examination, screening for color vision deficiency, and non-strabismic binocular vision anomalies. Those who failed screening underwent, objective and subjective refraction, and identification of other ocular conditions. Astigmatism was defined as cylindrical power greater than 0.50D. Refractive errors were classified into myopia (≤0.50D), hyperopia (≥0.75D), and other refractive errors (between -0.50D and +0.75D). The data on astigmatism were analyzed and were deduced into its vector components (M, J0 and J45). Descriptive statistics and regression analysis were performed. RESULTS: Data of 245,565 children from 1047 schools were taken for analysis. The average age was 11.63 ± 3.32 (range:6-17) years. After screening, refractive errors and astigmatism was found to be 6.57% (n = 16157) and 3.69% (n = 9064), respectively. Astigmatism among children aged 6 to 10 years was 1.37%. The mean cylindrical power, J0, and J45 was found to be 1.93 ± 1.06D, 0.06 ± 0.59D, and 0.43 ± 0.81D, respectively. Linear regression showed a decreasing trend in the cylindrical component (p < .001) and shift towards less positive J0 values (p < .001). Higher proportions of astigmatism more than 1.50 D (1.83%,n = 4578) and unilateral astigmatism (1.20%,n = 2952) are evident among refractive errors. CONCLUSION: More than 50% of children who failed vision screening with refractive errors presented with astigmatism. Prevalence was higher among primary school children. Presence of higher magnitude and unilateral astigmatism is amblyogenic and needs early intervention.

Significant increase in astigmatism in children after study at home during the COVID-19 lockdown.

CLINICAL RELEVANCE: Evaluating changes in refractive astigmatism after 'study at home' during the COVID pandemic may shed light on the aetiology of refractive errors. BACKGROUND: To investigate whether there has been a change in the proportion of astigmatism among primary school children after the school closure period during the COVID-19 pandemic. METHODS: This observational study compared cross-sectional (2018: n = 112; 2020: n = 173) and longitudinal data (n = 38) collected from two vision screenings, one in 2018 and the other after the school closure period in 2020, in the same primary school for children aged 8-10 years. Non-cycloplegic refraction and axial length were measured using an open-field auto-refractometer and IOL Master, respectively. A questionnaire focusing on demographic information, near-work time, and outdoor activities was administered to parents of all participants. RESULTS: While there were no significant differences in age, gender, or monthly family income between the two cohorts, astigmatism proportion (Cyl ≥ 0.75 D) in 2020 was 1.5-fold higher than that in 2018 (49.1% vs. 33.9%). The median cylindrical power was significantly higher in 2020 in older children (9 or 10 years old). More importantly, the children participating in both vision screenings had cylindrical power and J0 astigmatism significantly increased by 0.35 ± 0.40 D and 0.21 ± 0.25 D, respectively. CONCLUSION: A significant increase in astigmatism (both proportion and magnitude) was found after the school closure period. Further studies are needed to investigate the origin of this increased astigmatism.

Differential compensatory role of internal astigmatism in school children and adults: The Hong Kong Children Eye Study.

BACKGROUND: To compare the prevalence of refractive (RA), corneal (CA), and internal astigmatism (IA) in Hong Kong children and adults and evaluate the role of IA in compensating for total astigmatism and its relations to myopic traits. METHODS: The Hong Kong Children Eye Study is a population-based cross-sectional study. Totally 3704 school children (mean age 7.5 ± 1.0 years) and 5577 adults (mean age 41.1 ± 7.5 years), who were their parents, were recruited. Cycloplegic and non-cycloplegic refractive cylinders were obtained from children and adults, respectively. Spearman correlation was applied to detect associations between astigmatism, ocular biometrics, refraction, and lens power. Astigmatism compensation factor (CF) was derived from the power vector analysis J0 and J45. RESULTS: The prevalence of RA (≤-1.0 D), CA (≥+1.0 D) and IA (≥+1.0 D) was 21.9%, 63.9%, and 9.9% in children, and 30.9%, 39.5%, and 23.7% in adults respectively. The mean RA, CA and IA values in children and adults were -0.69 ± 0.66 D, +1.14 ± 0.61 D, +0.62 ± 0.32 D, and -0.80 ± 0.74 D, +0.97 ± 0.69 D, and +0.76 ± 0.43 D, respectively. In adults and children, IA was negatively correlated with axial length (p < 0.0001), but positively correlated with spherical values and equivalent (p < 0.0001), suggesting an association of astigmatism with myopic traits. A greater proportion of children exhibited compensation by IA than adults in J0 (86.6% vs. 66.0%, p < 0.0001) and J45 components (55.5% vs. 41.7%, p < 0.0001). CONCLUSIONS: Chinese children in Hong Kong exhibit a higher prevalence of RA and CA than in other cities. Children displayed a greater compensation by IA than adults, suggesting an age-related attenuation of IA compensation. IA is associated with myopic traits.

Refractive Error in a Chinese Population with Type 2 Diabetes: A Report from the Fushun Diabetic Retinopathy Cohort Study.

PURPOSE: To describe the prevalence and risk factors for refractive errors in a northeastern Chinese population with type 2 diabetes. METHODS: Subjects (age ≥30 years) from a community-based study, the Fushun Diabetic Retinopathy Cohort Study, were enrolled. All subjects underwent comprehensive ocular examinations, including autorefraction. Myopia, high myopia, and hyperopia were defined as a spherical equivalent (SE) of the right eye <-0.5 diopter (D), <-5.0D, and >0.5D, respectively. Astigmatism was defined as cylinder <-0.5D in a minus cylinder prescription. Anisometropia was defined as a difference of SE >1.0D between two eyes. RESULTS: A total of 1929 participants (790 males, 41.0%) were enrolled. The age and gender standardized prevalence of myopia, high myopia, hyperopia, astigmatism, and anisometropia were 43.1% (95% confidence interval [CI]: 40.9%-45.3%), 8.5% (95% CI: 7.3%-9.8%), 21.5% (95% CI: 19.7%-23.4%), 61.0% (95% CI: 58.9%-63.2%), and 17.2% (95% CI: 15.5%-18.9%), respectively. Advancing age was associated with a higher frequency of hyperopia, astigmatism, and anisometropia, as opposed to a lower frequency of myopia. Female (adjusted odds ratio [aOR], 1.27; 95% CI, 1.02-1.57) participants, higher intraocular pressure (aOR, 1.03; 95% CI, 1.00-1.07), and lenticular opacity (aOR, 1.53; 95% CI, 1.20-1.94) were also found to be associated with myopia. Long duration of diabetes (>15 years) was found to be a significant factor for astigmatism (aOR, 1.62; 95% CI, 1.15-2.27) and anisometropia (aOR, 1.87; 95% CI, 1.29-2.71). CONCLUSION: Nearly two-thirds of participants with type 2 diabetes had a refractive error. Age is a common factor with different types of refractive errors.

Refractive Error among Children Visiting the Department of Paediatric Opthalmology of a Tertiary Eye Care Center.

Introduction: Refractive error is the inability of eyes to focus clearly on images. Visual impairment due to refractive error has a major impact on children's education and daily activities. The hospital has no documentation of the ocular morbidity related to refractive errors in children. The aim of this study was to find out the prevalence of refractive error in children visiting the Department of Paediatric Ophthalmology of a tertiary care centre. Methods: A descriptive cross-sectional study was done in the Outpatient Department of Paediatric Ophthalmology in a tertiary care centre from 8 September 2022 to 7 March 2023 after obtaining ethical approval from the Institutional Review Committee. A convenience sampling method was used. The point estimate was calculated at 95% Confidence Interval. Results: Among 3600 children, the prevalence of refractive error was seen in 668 children (18.56%) (15.61-21.51, 95% Confidence Interval). Refractive error was seen in 363 (54.34%) boys and 305 (45.66%) girls. Myopia was found in 340 (50.90%), astigmatism in 207 (30.99%), and hyperopia in 121 (18.11%). Conclusions: The prevalence of refractive error among children attending a tertiary care centre was found to be higher than studies done in similar settings. Regular screening of refractive error for visual impairment is recommended among school going children. Keywords: astigmatism; hyperopia; myopia; refractive error; visual impairment.

Early Detection of Refractive Errors by Photorefraction at School Age.

Early detection and treatment of refractive defects during school age are essential to avoid irreversible future vision loss and potential school problems. Previously, vision screening of preschool children used methods based on subjective visual acuity; however, technologies such as photorefraction have promoted the detection of refractive errors quickly and easily. In this study, 1347 children from 10 schools in Madrid aged 4 to 12 years participated in a program of early detection of visual problems, which consisted of visual screening composed of anamnesis and photorefraction with a PlusOptix A12R. The prevalence of refractive errors was analyzed in terms of spherical equivalent, cylinder and its orientation, and potential cases of development of high myopia or amblyopia. Hyperopia predominates in the early years, but the number of myopic subjects is higher than that of hyperopic subjects from the age of ten onwards. At all ages, the predominant orientation of astigmatism was with-the-rule. On average, 80% of the myopic subjects were uncorrected. Potential high myopia increased with age, from 4 to 21% of the measured population. Potential amblyopia cases decreased across age groups, from 19 to 13.7%. There is a need to raise awareness of the importance of vision screening at school age to address vision problems.

Association of Maternal and Paternal Astigmatism With Child Astigmatism in the Hong Kong Children Eye Study.

Importance: Parental astigmatism is a factor associated with risk for development of child astigmatism; however, the magnitude of the association has not been determined. Objective: To determine the association between parental and child astigmatism. Design, Setting, and Participants: This population-based, cross-sectional study included participants from familial trios, each comprising a child aged 6 to 8 years and both parents, recruited from the Hong Kong Children Eye Study. No restriction criteria were set on the children in terms of refractive status. Data were analyzed from February to June 2022. Exposures: Cycloplegic autorefraction and autokeratometry were conducted on the children, whereas noncycloplegic autorefraction and autokeratometry were conducted on their parents. The children were categorized into 6 groups on the basis of the severity of astigmatism of both parents. Information on parental education, family income, and children's outdoor and near work time were obtained by questionnaires. Main Outcomes and Measures: The primary outcome was the odds of child astigmatism among the 6 categories of children. Associations of factors with child astigmatism were evaluated by logistic regression analyses. Results: A total of 17 124 participants from 5708 trios (2964 boys and 2754 girls) at a mean (SD) age of 7.32 (0.87) years, and 11 416 parents were examined. Astigmatism of 1.0 D or greater in both parents was associated with greater odds of refractive astigmatism (RA) (odds ratio [OR], 1.62; 95% CI, 1.15-2.26) and corneal astigmatism (CA) (OR, 1.94; 95% CI, 1.50-2.50) in the child. The respective ORs increased to 3.10 (95% CI, 1.34-7.21) and 4.31 (95% CI, 1.76-10.55) when both parents had astigmatism 2.0 D or greater. Higher parental astigmatism conferred higher risks for both RA and CA in children (P for trend <.001). Parental astigmatism was significantly associated with greater odds of corresponding child astigmatism (maternal RA: OR, 0.76; 95% CI, 0.68-0.84; paternal RA: OR, 0.82; 95% CI, 0.74-0.91; maternal CA: OR, 1.70; 95% CI, 1.51-1.93; paternal CA: OR, 1.33; 95% CI, 1.19-1.49). Conclusions and Relevance: The findings of this cross-sectional study suggest that parental astigmatism may confer an independent and dose-dependent association with child astigmatism. Children with parents with astigmatism should have early eye examinations for timely detection of astigmatism to facilitate age-appropriate vision correction and visual development.