The prevalence of amblyopia in 7–9-year-old schoolchildren in Mashhad

Background: To determine the prevalence of amblyopia in schoolchildren aged 7–9 years old in Mashhad, Iran. Methods: This was a cross-sectional, community-based study with schoolchildren aged 7–9 years old. We randomly selected 20 of 189 elementary schools (three schools per district; 10 male-segregated and 10 female-segregated schools) from a proportional combination of public schools across Mashhad. Basic vision exams were performed. If amblyopia was suspected, children underwent supplementary vision exams. The diagnostic criterion for amblyopia was a best corrected visual acuity (BCVA) in one or both eyes equal to or worse than 20/40 or an interocular difference of more than two lines in BCVA without any significant organic pathology. Results: A total of 2831 children were included in the study. All children were examined comprehensively by an optometrist, and amblyopia was detected in 49/2831 (1.7% [95% CI, 1.22?2.18]). Of the 49 children with amblyopia, 20 (40.8%) were amblyopic in the right eye, 9 (18.4%) in the left eye, and 20 (40.8%) in both eyes. Twenty-four (49%) were first graders, 15 (30.6%) were second graders, and 10 (20.4%) were third graders. The most prevalent subtype of amblyopia was anisometropic amblyopia (57.1%, [95% CI, 43.24?70.96]). Conclusions: Considering the prevalence of amblyopia among schoolchildren aged 7–9 years old (1.7%), timely detection of amblyopia through preschool screening programs is essential for early treatment or prevention of further visual impairment during childhood. How to cite this article: Shahpary S, Ramin S, Azimi A, Heyrani M. The prevalence of amblyopia in 7-9-year-old schoolchildren in Mashhad. Med Hypothesis Discov Innov Optom.2021 Spring; 2(1): 18-23. DOI: https://doi.org/10.51329/mehdioptometry12

Mexico City Normal Weight Children Exposed to High Concentrations of Ambient PM\u3csub\u3e2.5\u3c/sub\u3e Show High Blood Leptin and Endothelin-1, Vitamin D Deficiency, and Food Reward Hormone Dysregulation versus Low Pollution Controls. Relevance for Obesity and Alzheimer Disease

Millions of Mexico, US and across the world children are overweight and obese. Exposure to fossil-fuel combustion sources increases the risk for obesity and diabetes, while long-term exposure to fine particulate matter (PM 2.5) and ozone (O3) above US EPA standards is associated with increased risk of Alzheimer’s disease (AD). Mexico City Metropolitan Area children are chronically exposed to PM2.5 and O3 concentrations above the standards and exhibit systemic, brain and intrathecal inflammation, cognitive deficits, and Alzheimer disease neuropathology. We investigated adipokines, food reward hormones, endothelial dysfunction, vitamin D and apolipoprotein E (APOE) relationships in 80 healthy, normal weight 11.1±3.2 years olds matched by age, gender, BMI and SES, low (n: 26) versus high (n:54) PM 2.5 exposures. Mexico City children had higher leptin and endothelin-1 (p 2.5 exposed children. Mexico City APOE 4 v 3 children had higher glucose (p=0.009). Serum 25-hydroxyvitamin D \u3c 30 ng/mL was documented in 87% of Mexico City children. Leptin is strongly positively associated to PM 2.5 cumulative exposures. Residing in a high PM2.5 and O3 environment is associated with 12 h fasting hyperleptinemia, altered appetite-regulating peptides, vitamin D deficiency, and increases in ET-1 in clinically healthy children. These changes signal the future trajectory in urban children towards the development of insulin resistance, obesity, type II diabetes, premature cardiovascular disease, addiction-like behavior, cognitive impairment and Alzheimer’s disease. Increased efforts should be made to decrease pediatric PM 2.5 exposures, to deliver health interventions prior to the development of obesity and to identify and mitigate environmental factors influencing obesity and Alzheimer disease

Little evidence for an epidemic of myopia in Australian primary school children over the last 30 years

BACKGROUND: Recently reported prevalences of myopia in primary school children vary greatly in different regions of the world. This study aimed to estimate the prevalence of refractive errors in an unselected urban population of young primary school children in eastern Sydney, Australia, between 1998 and 2004, for comparison with our previously published data gathered using the same protocols and other Australian studies over the last 30 years. METHODS: Right eye refractive data from non-cycloplegic retinoscopy was analysed for 1,936 children aged 4 to 12 years who underwent a full eye examination whilst on a vision science excursion to the Vision Education Centre Clinic at the University of New South Wales. Myopia was defined as spherical equivalents equal to or less than -0.50 D, and hyperopia as spherical equivalents greater than +0.50 D. RESULTS: The mean spherical equivalent decreased significantly (p < 0.0001) with age from +0.73 ± 0.1D (SE) at age 4 to +0.21 ± 0.11D at age 12 years. The proportion of children across all ages with myopia of -0.50D or more was 8.4%, ranging from 2.3% of 4 year olds to 14.7% of 12 year olds. Hyperopia greater than +0.50D was present in 38.4%. A 3-way ANOVA for cohort, age and gender of both the current and our previous data showed a significant main effect for age (p < 0.0001) but not for cohort (p = 0.134) or gender (p = 0.61). CONCLUSIONS: Comparison of our new data with our early 1990s data and that from studies of over 8,000 Australian non-clinical rural and urban children in the 1970's and 1980's provided no evidence for the rapidly increasing prevalence of myopia described elsewhere in the world. In fact, the prevalence of myopia in Australian children continues to be significantly lower than that reported in Asia and North America despite changing demographics. This raises the issue of whether these results are a reflection of Australia's stable educational system and lifestyle over the last 30 years

Validation of dynamic random dot stereotests in pediatric vision screening

Purpose: Stereo vision tests are widely used in the clinical practice for screening amblyopia and amblyogenic conditions. According to literature, none of these tests seems to be suitable to be used alone as a simple and reliable tool. There has been a growing interest in developing new types of stereo vision tests, with sufficient sensitivity to detect amblyopia. This new generation of assessment tools should be computer based, and their reliability must be statistically warranted. The present study reports the clinical evaluation of a screening system based on random dot stereograms using a tablet as display. Specifically, a dynamic random dot stereotest with binocularly detectable Snellen-E optotype (DRDSE) was used and compared with the Lang II stereotest. Methods: A total of 141 children (aged 4–14, mean age 8.9) were examined in a field study at the Department of Ophthalmology, Pécs, Hungary. Inclusion criteria consisted of diagnoses of amblyopia, anisometropia, convergent strabismus, and hyperopia. Children with no ophthalmic pathologies were also enrolled as controls. All subjects went through a regular pediatric ophthalmological examination before proceeding to the DRDSE and Lang II tests. Results: DRDSE and Lang II tests were compared in terms of sensitivity and specificity for different conditions. DRDSE had a 100% sensitivity both for amblyopia (n = 11) and convergent strabismus (n = 21), as well as a 75% sensitivity for hyperopia (n = 36). However, the performance of DRDSE was not statistically significant when screening for anisometropia. On the other hand, Lang II proved to have 81.8% sensitivity for amblyopia, 80.9% for strabismus, and only 52.8% for hyperopia. The specificity of DRDSE was 61.2% for amblyopia, 67.3% for strabismus, and 68.6% for hyperopia, respectively. Conversely, Lang II showed about 10% better specificity, 73.8% for amblyopia, 79.2% for strabismus, and 77.9% for hyperopia. Conclusions: The DRDSE test has a better sensitivity for the detection of conditions such as amblyopia or convergent strabismus compared with Lang II, although with slightly lower specificity. If the specificity could be further improved by optimization of the stimulus parameters, while keeping the sensitivity high, DRDSE would be a promising stereo vision test for screening of amblyopia.This study was supported by the EFOP-3.6.1.-16-2016-00004: Comprehensive Development for Implementing Smart Specialization Strategies at the University of Pécs and by the European Union, co-financed by the European Social Fund KTIA_NAP_13-1-2013-0001: Brain Research Program; 2017-1.2.1.-NKP-2017-00002: Brain Research Program 2.0; OTKA K108747, PTE ÁOK-KA-2017-06, EFOP-3.6.3-VEKOP-16-2017-00009, 20765-3/2018/FEKUTSTRAT “Central mechanisms of stereopsis”, National Excellence Program TÁMOP-4.2.4.A/ 2-11/1-2012-0001

Visual function assessment in medical imaging research

Background: Medical image perception research relies on visual data to study the diagnostic relationship between observers and medical images. A consistent method to assess visual function for participants in medical imaging research has not been developed and represents a significant gap in existing research. Methods: Three visual assessment factors appropriate to observer studies were identified: visual acuity, contrast sensitivity, and stereopsis. A test was designed for each, and 30 radiography observers (mean age 31.6 years) participated in each test. Results: Mean binocular visual acuity for distance was 20/14 for all observers. The difference between observers who did and did not use corrective lenses was not statistically significant (P ! .12). All subjects had a normal value for near visual acuity and stereoacuity. Contrast sensitivity was better than population norms. Conclusion: All observers had normal visual function and could participate in medical imaging visual analysis studies. Protocols of evaluation and populations norms are provided. Further studies are necessary to understand fully the relationship between visual performance on tests and diagnostic accuracy in practice

Refractive and axial development of the growing eye

This thesis aimes to illustrate and describe the current status of refraction and axial length in German children and adolescents. In contrast to previous studies growth curves were generated, instead of analysing myopia prevalence at separate age groups. This allows for an easier understanding and comparison of eye development.:Introduction and Motivation Aims Background Refractive development in infants and children Eye-growth and axial length Methods Study population Measurements Statistical analysis Cumulative part Refractive status in a German paediatric cohort: A cross-sectional analysis of the LIFE Child data Reference curves for refraction in a German cohort of healthy children and adolescents Longitudinal analysis of axial length growth in a German cohort of healthy children and adolescents Zusammenfassung der Arbeit Summary Conclusion Prospect References Appendix Einreichungserklärung Declaration Wissenschaftliche Beiträge zu den Publikationen Acknowledgment

Regional cerebral blood flow during wakeful rest in older subjects with mild to severe obstructive sleep apnea

Objectives: To evaluate changes in regional cerebral blood flow (rCBF) during wakeful rest in older subjects with mild to severe obstructive sleep apnea (OSA) and healthy controls, and to identify markers of OSA severity that predict altered rCBF. Design: High-resolution 99mTc-HMPAO SPECT images during wakeful rest. Setting: Research sleep laboratory affiliated with a University hospital. Participants: Fifty untreated OSA patients aged between 55 and 85 years divided into mild, moderate and severe OSA and 20 age-matched healthy controls. Interventions: N/A Measurements: Using statistical parametrical mapping, rCBF was compared between groups and correlated with clinical, respiratory and sleep variables. Results: Whereas no rCBF change was observed in mild and moderate groups, participants with severe OSA had reduced rCBF compared to controls in the left parietal lobules, precentral gyrus, bilateral postcentral gyri, and right precuneus. Reduced rCBF in these regions and in areas of the bilateral frontal and left temporal cortex was associated with more hypopneas, snoring, hypoxemia, and sleepiness. Higher apnea, micro-arousal, and body mass indexes were correlated to increased rCBF in the basal ganglia, insula, and limbic system. Conclusions: While older individuals with severe OSA had hypoperfusions in the sensorimotor and parietal areas, respiratory variables and subjective sleepiness were correlated with extended regions of hypoperfusion in the lateral cortex. Interestingly, OSA severity, sleep fragmentation and obesity correlated with increased perfusion in subcortical and medial cortical regions. Anomalies with such a distribution could result in cognitive deficits and reflect impaired vascular regulation, altered neuronal integrity, and/or undergoing neurodegenerative processes

Variação da frequência da anisometropia com o percurso escolar

A anisometropia caracteriza-se por ser um distúrbio da visão binocular em que o grau de ametropia é significativamente diferente entre os dois olhos. Apesar de não haver um valor uniformemente definido, uma diferença interocular de 1,00 dioptria ou mais é o limiar utilizado pela maioria dos autores. A prevalência desta condição depende de vários fatores, podendo variar consoante o critério de classificação utilizado, a faixa etária estudada ou até mesmo entre diferentes áreas geográficas. O presente estudo tem como objetivo estimar a frequência da anisometropia em várias etapas do percurso escolar, desde o ensino pré-escolar até ao 3º ciclo do ensino básico, estudando a sua associação com género, ciclo de estudos e área de residência. Metodologia: Os dados foram recolhidos no âmbito de rastreios visuais realizados em escolas locais. A amostra final contou com 749 crianças (350 meninas e 399 meninos). Na aquisição dos dados, as medições refrativas foram obtidas com o auto-refratómetro pediátrico portátil (plusoptiX), sem cicloplégico e em condições binoculares. Considerou-se anisometropia uma diferença na refração interocular de pelo menos 1,25 dioptrias. Resultados: A frequência de anisometropia foi de 5,21% na amostra total, sendo a anisometropia miópica a mais frequente e a anisometropia antimetrópica a menos frequente. A anisometropia hipermetrópica e o aniso-astigmatismo apresentam proporções de ocorrência idênticas, na população estudada. Não se encontraram evidências estatísticas para se afirmar que a ocorrência da anisometropia difira entre os géneros ou entre as áreas de residência. Relativamente ao ciclo escolar, encontrou-se uma associação significativa com a anisometropia esférica, observando-se um aumento da frequência da anisometropia com o avanço escolar, sendo a anisometropia miópica a que mais contribuiu para esta variação. Conclusão: O avanço no percurso escolar leva a que o esforço exigido pelo trabalho ao perto seja cada vez maior, sendo também um fator de risco para o aumento da miopia. Este facto pode estar relacionado com o aumento da anisometropia miópica com o percurso escolar, encontrada neste estudo. A realização de rastreios visuais nesta idade revela-se essencial na deteção precoce e na correção adequada da anisometropia e de outras condições oculares, que possam prejudicar o desenvolvimento e a aprendizagem.Anisometropia is characterized by being a binocular vision disorder in which the degree of ametropia is significantly different between the two eyes. Although there is no uniformly defined value, an interocular difference of 1.00 diopter or more is the threshold used by most authors. The prevalence of this condition depends on several factors, and may vary depending on the criterion used, the age group studied or even between different geographical areas. This study aims to estimate the frequency of anisometropia in various stages of the school path, from pre-school to the 3rd cycle of basic education, studying its association with gender, study cycle and area of residence. Methodology: The data were collected as part of visual screenings carried out in local schools. The final sample included 749 children (350 girls and 399 boys). In the acquisition of the data, the refractive measurements were obtained with the portable pediatric auto-refractometer (plusoptiX), without cycloplegic and in binocular conditions. Anisometropia was considered as a difference in interocular refraction of 1.25 diopters or more. Results: The frequency of anisometropia was 5.21% in the total sample, with myopic anisometropia being the most frequent and antimetropic anisometropia being the least frequent. Hyperopic anisometropia and aniso-astigmatism present identical proportions in the studied population. No statistical evidence was found to state that the occurrence of anisometropia differs between genders or between areas of residence. Regarding the school cycle, a significant association was found with spherical anisometropia, with an increase in the frequency of anisometropia with school progression, being myopic anisometropia the one that most contributed to this variation. Conclusions: The school progression leads to the fact that the effort required for near work is increasingly greater, being also a risk factor for the increase of myopia. This fact may be related to the increase in myopic anisometropia with the school progression, found in this study. Visual screening at this age is essential for the early detection and proper correction of anisometropia and other eye conditions, which can impair development and learning