Prevalence Of Astigmatism Research Articles

Astigmatism and its Associated Factors in Pediatric Population, Nepal

Introduction: Astigmatism is a common vision disorder that leads to blurred vision due to the inability of the ocular system to form a sharply focused image on the retina. A child with uncorrected astigmatism experiences blur on a continuous basis and also child has a clear retinal image when looking at a near environment. Objective: The objective of this study was to access the prevalence and risk factors associated with Astigmatism in pediatric population. Method: This was a hospital based cross sectional study conducted among 2 to 14 years children with astigmatism of ≥ 1.0 D in either eye. Study conducted from 1st September 2022 to 28th February 2023. Data was entered in Ms-Excel and further analyzed in SPSS Version 12.0. Result: Prevalence of astigmatism was found to be 38.80%. Prevalence in Male was found to be higher 65.20% than in female. Age was found to be statistically significant p = (0.003) with astigmatism. Conclusion: Astigmatism is a common vision disorder that leads to blurred vision due to the inability of the ocular system to form a sharply focused image on the retina. Concerned stakeholder need to screen the problem to minimize preventable blindness in children.

Epidemiological Characteristics Associated with Astigmatism in a Population of 3- to 5-Year-Old Children in Los Angeles, CA

ABSTRACT Purpose To characterize the prevalence of astigmatism among the heretofore largest published sample of preschool children and to do so among different age, gender, and racial and ethnic subgroups. Methods This study included data from 79,330 preschoolers (49.0% female, 79.4% Latino, mean age 4.29 ± 0.66 years) who were screened using a Retinomax autorefractor between 2012 and 2017. Cylindrical power and astigmatism defined as 1.50 D or more of cylinder were the dependent variables. Children were stratified by age, race/ethnicity, and gender. T-test and chi-square analyses were performed. Results The average cylinder of the sample was found to be 0.65 ± 0.78 D and 11% of the children were astigmatic. Among all children, these values remain stable from age 3 (0.66 ± 0.76 D, 11.2%) to age 4 (0.66 ± 0.79 D, 11.4%, p = .53), but they decrease significantly from age 4 to age 5 (0.61 ± 0.80 D, 10.%, p < .01). Latinos have the highest average cylinder power and prevalence of astigmatism at 0.68 ± 0.82 D and 12.3%, and unlike most other race/ethnic subgroups, they do not experience an age-dependent decrease in astigmatism. While female and male students have equivalent cylindrical refractions broadly, Asian and African American females have higher levels of astigmatism than their male counterparts. Conclusion The data further demonstrate that Latino children in Los Angeles have significantly higher rates of astigmatism, which does not decrease during preschool years. These results emphasize the need for comprehensive school-based screening, especially among Latino enclaves in Los Angeles.

Astigmatism among schoolchildren in Mumbai, India: a large, population-based study

Background: Astigmatism is a common refractive error. If left untreated, it may result in blurred or distorted vision. We determined the prevalence of astigmatism in schoolchildren aged 6–16 years in Mumbai, India. Methods: A cross-sectional study was conducted using a stratified cluster random sampling method. We included primary and secondary schoolchildren aged 6–16 years. All children underwent a comprehensive eye examination. Astigmatism was characterized as having a diopter cylinder (DC) power of 0.50 or more in at least one eye, and for prevalence estimation, we reported the number of children with astigmatism. Astigmatism severity was defined as mild (less than or equal to - 1.50 DC), moderate (- 1.50 DC to - 2.50 DC), and severe (&gt; - 2.50 DC). Based on the axis orientation, astigmatism was categorized as with-the-rule, against-the-rule, and oblique. Results: A total of 3151 schoolchildren with a mean (standard deviation) age of 12.1 (2.9) years were screened; boys and girls accounted for 49.22% and 50.78%, respectively. Age groups of 6–9, 10–13, and 14–16 years accounted for 51.35%, 28.53%, and 20.12%, respectively. The overall prevalence of astigmatism was 11.46%, with no significant difference between sexes (P &gt; 0.05). The prevalences of astigmatism in the groups aged 6–9-, 10–13-, and 14–16 years were 5.24%, 3.49%, and 2.73%, respectively. Prevalence differed significantly among age groups (P &lt; 0.05), with a trend of decreasing prevalence with increasing age. No significant association was found between age and severity of astigmatism (P &gt; 0.05). The prevalences of mild, moderate, and severe astigmatism were 6.51%, 3.11%, and 1.84%, respectively. Mild astigmatism was significantly more prevalent than moderate (P &lt; 0.05) or severe astigmatism (P &lt; 0.05). The prevalence of astigmatism differed significantly among the three orientations of axis (P &lt; 0.001). The prevalences were 9.20%, 1.68%, and 0.57% for with-the-rule, against-the-rule, and oblique astigmatism, respectively. We found a statistically significant difference in the prevalences of astigmatism based on the axis orientation between boys and girls (P &lt; 0.05) and between age groups (P &lt; 0.001), with a decreasing trend observed with increasing age. Conclusions: We found a prevalence of 11.46% for astigmatism among schoolchildren aged 6–16 years in Mumbai, India. There was a decreasing trend in prevalence with increasing age, with no difference between sexes. The prevalence was the highest for mild astigmatism, followed by moderate and severe astigmatism. Prevalence differed significantly based on the axis orientation among the three subtypes, age groups, and between the two sexes, with a decreasing trend with increasing age. With-the-rule astigmatism was the most common, followed by against-the-rule astigmatism; oblique astigmatism was the least common.

Characteristics of astigmatism in school-age children aged 5 to 13 years in northeast Sichuan: a cross-sectional school-based study.

Astigmatism is closely associated with myopia progression, vision loss, eye fatigue and amblyopia, which seriously endangers children's eye health. This study aims to investigate the prevalence and characteristic distribution of astigmatism in children in Langzhong City, providing valuable insights for allocating resources and develop prevention and control strategies. A cross-sectional study and random sampling survey were conducted. Between January and November 2021, 21,415 students aged 5 to 13 years from 14 primary schools in Langzhong City underwent non-cycloplegic refractive testing using autorefraction. The data on myopia were analyzed using SPSS (Statistical Package for the Social Sciences) version 23.0. The inclusion criterion was set at an absolute astigmatism value of ≥0.50D. Among the 21,415 children studied, 61.70% were found to have astigmatism. The prevalence of astigmatism varied significantly across different grades (χ2=501.414, P<0.001). The predominant types of astigmatism were mild astigmatism (0.50-1.00D) and with-the-rule astigmatism. Mixed astigmatism was primarily observed in children in grades 1 and 2, while compound myopic astigmatism was more common in children in grades 3 to 6. These differences were statistically significant. As the degree of astigmatism increased, the proportions of against-the-rule astigmatism, oblique astigmatism, compound myopic astigmatism, and simple hyperopic astigmatism decreased, whereas the proportions of with-the-rule astigmatism, mixed astigmatism, and compound hyperopic astigmatism increased. The prevalence of astigmatism among school-age children aged 5 to 13 years in northeast Sichuan is notably high, with compound myopic astigmatism and with-the-rule astigmatism being the most common types. Regular refractive examinations are crucial for the early detection and management of astigmatism.

Refractive Error of the Elderly Presenting to a University Eye Clinic

The prevalence of refractive errors varies by age and gender and is closely related to functional difficulties, ocular diseases, and decreased quality of life. The purpose of this study was to assess associations of age and gender with refractive errors of the elderly presenting at a university clinic. Retrospective review of medical records of elderly patients presenting for eye services in 2020-2021. Demographic, ocular disease and refractive data were collected and analyzed. The number of 1,452 patients aged 60 and over with a mean age of 69.6 ± 8.09 years (range 60 to 101 years) were included. The prevalence of myopia, hyperopia, astigmatism, and anisometropia was 22.4%, 36.5%, 22.7%, and 19.4%, respectively. Compared to those aged 80 and above, myopia increased 5.171 times in those 60-69 yrs and 4.930 times among those 70-79 yrs. Men were significantly more likely to have myopia than women (p&lt;0.001). Hyperopia was significantly less prevalent in those aged 70-79 and aged 80 and above compared to those aged 60-69 (p&lt;0.001). Gender was not associated with hyperopia (p=0.066). The prevalence of astigmatism and anisometropia was higher in older subjects. Astigmatism shifted from with-the-rule (WTR) to against-the-rule (ATR) with age. Astigmatism had no gender difference, but anisometropia was more common in women. Most anisometropia was due to refractive error. Rates of myopia and hyperopia decreased with age while astigmatism increased with age. Thai optometrists need to be aware that refractive error in the elderly is not stationary and frequent changes in spectacle power may be needed.

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

BackgroundTo investigate the prevalence and risk factors for astigmatism in 7-19-year-old students in Xinjiang, China.MethodsA 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).ResultsOf 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).ConclusionsThe 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.

PREVALENSI KEJADIAN ASTIGMATISME (MATA SILINDER) PADA MAHASISWA UNIVERSITAS MA CHUNG MALANG PADA BULAN JULI TAHUN 2024 Prevalence Of Astigmatism (Cylinder Eye) In Students Of Ma Chung University Malang In July 2024

Astigmatism is a refractive disorder caused by uneven curvature of the cornea or lens, causing light not to focus on the retina. This study aims to measure the prevalence of astigmatism among students at Ma Chung University and identify the relationship between the duration and position of gadget use with astigmatism. The study method used a cross-sectional design involving 125 students aged 17–24 years. Data were collected through questionnaires and eye examinations using a Snellen chart and keratometer. The results showed that 38.4% of students had astigmatism. Most students (96.8%) used gadgets for more than 2 hours a day, and 91.2% used gadgets in a lying position. Using gadgets in this position and for long durations increases the risk of astigmatism. The conclusion of this study is that astigmatism is a significant problem among students. Implementation of the 20-20-20 rule and increasing outdoor activities are recommended for prevention. Routine eye examinations are also needed so that disorders can be detected and treated early.

Prevalence of Astigmatism in Children Visiting Headache Clinic at a Hospital in Rural Karnataka

Background Vision plays an important role in childrenrsquos learning. Uncorrected refractive errors are the leading cause of avoidable visual impairment in children and can be corrected effectively with early diagnosis and treatment. Screening for vision in school children is essential as most of the refractive errors manifest after 10-12 years of age.Objectives To estimate the prevalence of astigmatism among children visiting the Headache clinic at a tertiary hospital Akash Institute of Medical Sciences and Research Centre Devanahalli Bangalore.Methods The visual acuity of 300 children who visited the Headache clinic was measured using a LogMAR Logarithm of the Minimum Angle of Resolution chart. The children with reduced visual acuity were checked for astigmatism using a streak retinoscope.Results The age of all the randomly enrolled 300 children ranged between 5 and 16 years. Astigmatism was recorded in 30 students 18 females 10.34 and 12 males 9.52. Conclusion The astigmatism prevalence among children who visited a tertiary Headache clinic in rural Karnataka was estimated as 10 in the present study.

The Prevalence of Astigmatism in 7 to 13 Years Old Children: A Cross-sectional Study

The Prevalence of Astigmatism in 7 to 13 Years Old Children: A Cross-sectional Study

Prevalence of keratoconus and subclinical keratoconus in subjects with two or more diopters (D) of astigmatism using pentacam derived parameters

Keratoconus is a common progressive asymmetric, bilateral, ectatic corneal disorder that arises due to biomechanical and structural defects in organization of corneal collagen. It is characterized by axial protrusion of cornea and thinning of corneal stroma which deforms the shape of cornea leading to myopia and irregular astigmatism with decreased vision. This is a prospective cross-sectional study. All the patients within age group of 8-45 years who attended Outpatient Department of a Tertiary Care Hospital, Ajmer, with signs and symptoms of keratoconus or with astigmatism ≥2D with no previous history of ocular trauma or surgery were evaluated and a complete ophthalmic examination was done including the best corrected visual acuity, retinoscopy, slit lamp biomicroscopy and fundus examination and the findings were recorded. Only subjects with no other signs and symptoms of other ocular pathology were included. 334 eyes (167 subjects) were included in this study and among 334 eyes, 291 eyes had ≥2 D Astigmatism, 152/167 (91.02%) right and 139/167 (83.23%) left eyes. Mean age of the patients was 19.6±9.09 years ranging from 8 to 45 years. 50.3% of study subjects were females and 49.7% were males. Overall, in both eyes, prevalence of astigmatism was found to be 73.88%, FFKCN was 10.31% and KCN was found 15.81% among the study population having ≥2 D astigmatism. Patients with astigmatism of ≥2D who attend outdoor clinics should be evaluated with corneal tomography for early diagnosis, even if visual acuity is not significantly affected. Pentacam gives a more accurate diagnosis than corneal topography devices used conventionally, particularly in keratoconus suspicious eyes.

The Prevalence of Astigmatism and Spectacle Wear in Polish Schoolchildren

ABSTRACT Introduction Unilateral or asymmetric astigmatism is considered a principal refractive error leading to amblyopia and regular eye examinations should be carried out during childhood to prevent visual impairment. The aim of this study was to evaluate the prevalence of astigmatism and spectacle wear among Polish schoolchildren. Methods A cross sectional study was carried out in children aged 6 to 14 years old from 50 schools in Poland. The presence of astigmatism was assessed by non-cycloplegic autorefraction, and defined as a cylinder equal or greater than 0.75 D. Children were classified as living in urban or rural areas according to the school location. Spectacle wear was defined as having spectacles at school. Results The study included 1041 children and 52.3% were girls (n = 544). The mean age was 8.62 ± 2.04 years. The prevalence of astigmatism was 7.3% (95% confidence interval [CI]: 5.8–9.1%). Only 21.7% of children with astigmatism wore spectacles at school. Astigmatism was diagnosed in 8.2% of boys (95% CI: 6.0–11.0%) and 6.4% of girls (95% CI: 4.5–8.8%; p = .13); cylindrical anisometropia was present in 19/76 (25.0%) of children with astigmatism (95% CI: 15.8%–36.3%). Against-the-rule astigmatism was the most common; it was observed in 48.7% of children with astigmatism, followed by with-the-rule astigmatism (44.7%) and oblique astigmatism (6.6%). The prevalence of astigmatism was not linearly correlated with age (r = 0.24; p = .53). Gender, age and place of living were not significantly associated with the presence of astigmatism. Conclusions This study reports a low prevalence of astigmatism in Polish school children. However, the majority of children with astigmatism were uncorrected. Further longitudinal studies are warranted.

Prevalence of refractive errors in children of Puerto Rico.

To determine the prevalence of refractive error in 5- to 17-year-old schoolchildren in Puerto Rico. A quantitative descriptive study of 2867 children aged 5 to 17y from all seven educational regions of Puerto Rico was conducted from 2016-2019. Refractive error was determined via static and subjective refraction. Children with distance acuity ≤20/40 or near visual acuity ≤20/32 had a cycloplegic refraction. Data analysis included descriptive statistics, correlation coefficient, Kruskal-Wallis, Chi-square, and t test calculations. Twenty percent of the children had a spherical equivalent refractive error ≤ -0.50 D, 3.2% had a spherical equivalent ≥ +2.00 D, and 10.4% had astigmatism ≥1 D. There was a statistically (but non-clinically) significant myopic change in spherical equivalent refractive error with age (P<0.001). The prevalence of myopia increased with age (P<0.001) but not hyperopia (P=0.59) or astigmatism (P=0.51). Males had a significantly higher hyperopic spherical equivalent than females (P<0.001). Females had a higher prevalence of myopia (P<0.001) than males, but there was no difference in the hyperopia (P=0.74) or astigmatism prevalence (P=0.87). The prevalence of a spherical equivalent equal to or less than -0.50 D (myopia, 20.7%) is one of the highest among similar-aged children worldwide. Further studies should explore the rate of myopia progression in children in Puerto Rico. Individual children must be monitored to examine the need for treatment of myopia progression.

Prevalence and Risk Factors of Refractive Errors and Effective Spectacle Coverage in Emiratis and Non-Emiratis Aged 40 Years or Older: the Dubai Eye Health Survey.

The aim was to investigate the prevalence and risk factors of refractive errors (REs) and the effective spectacle coverage in Emiratis and non-Emiratis in Dubai. The Dubai Eye Health Survey was a population-based cross-sectional study of participants aged 40 years or older. Distance and near visual acuity (VA), and noncycloplegic automated refraction were tested according to a standardized protocol. Distance VA was tested using the Early Treatment Diabetic Retinopathy Study (ETDRS) logMAR chart at 3m and near VA was measured using the near vision logMAR chart at 40cm under ambient lighting. Myopia was defined as spherical equivalent of refraction of less than -0.50 diopters (D), and hypermetropia as spherical equivalent of more than +0.50D. Astigmatism was defined as cylinder power of 0.5D or greater. Effective spectacle coverage for distance vision was computed as met need/(met need+unmet need+under-met need)×100%. Multivariable logistic regression models were used to examine associations between sociodemographic factors and RE. The authors included 892 participants (446 Emiratis and 446 non-Emiratis) in the analysis. The prevalence of hypermetropia was 20.4% [95% confidence interval (CI): 16.8%-24.4%] in Emiratis and 20.6% (95% CI: 20.0%-24.7%) in non-Emiratis. The prevalence of myopia and high myopia was 27.4% (95% CI: 23.3%-31.7%) and 1.8% (95% CI: 0.8%-3.5%) in Emiratis, and 19.5% (95% CI: 15.9%-23.5%) and 0.9% (95% CI: 0.2%-2.3%) in non-Emiratis, respectively. High education (P=0.02) and not currently working (P=0.002) were risk factors of myopia in non-Emiratis only. The prevalence of astigmatism was 7.4% (95% CI: 5.1%-10.2%) in Emiratis and 1.6% (95% CI: 0.6%-3.2%) in non-Emiratis. This prevalence was higher in individuals aged over 60 years (P<0.001) and men (P=0.014) among Emiratis. The prevalence of anisometropia and uncorrected presbyopia was 11.4% (95% CI: 8.6%-14.8%) and 0.7% (95% CI: 0.1%-2.0%) in Emiratis, and 9.2% (95% CI: 6.7%-12.3%) and 0.4% (95% CI: 0.05%-1.6%) in non-Emiratis, respectively. The effective spectacle coverage was 62.3% (95% CI: 54.0%-70.6%) and 69% (95% CI: 60.5%-77.5%) in Emiratis and non-Emiratis, respectively. A high proportion of Emiratis and non-Emiratis was affected by RE without optimal effective spectacle coverage, highlighting the imperativeness of intervention to alleviate the burden. The findings may help facilitate evidence-based policymaking concerning the delivery of eye care services and allocation of medical resources in Dubai.

Analysis on ocular biometric parameters in adult cataract surgery

Introduction: Biometrics are crucial in calculating IOL power for best refractive advantage in cataract surgery. Regional data provides insights on corneal astigmatism and facilitates forecasts but data for Sri Lankan population is lacking.Objective: To identify ocular biometry characteristics in Sri Lankans and compare with other populations.Method: A cross-sectional retrospective study assessed ocular biometry characteristics in consecutive cataract surgery candidates at a tertiary unit in National Eye Hospital of Sri Lanka between February and August 2021. Data from 237 eyes in 237 candidates of age over 40 and under 80 years were analysed. Data on Keratometry(K), axial length(AL) and IOL power were statistically analysed through SPSS software. Sample was divided as: age between 40-60 years and 60-80years. Descriptive statistics and unpaired t-test to compare means between groups were utilised.Results: Mean Age was 62.71±7.89 years. Mean AL was 23.11±1.11mm (range 21.00-30.56)mm with majority between 22-24mm(72.6%). Mean K was 44.25±1.57mm. IOL powers most used were between 23-25D (46.3%) (range 4D,28D). Mean astigmatism was 0.82±0.78D and 26.6%, 5.9% and 1.3% had over 1.0D, 2.0D and 3.0D respectively.Discussion: In males mean K was lower (43.80±1.62 vs 44.61±1.44) (p=0.00) and AL was longer (23.31±1.20 vs 22.94±1.01) (p=0.013). The older age group had shorter AL (p=0.006) and higher astigmatism(p=0.049). AL in our sample was shorter than Caucasians but comparable with other South Asian studies. Astigmatism prevalence was lower than other studies.Conclusion: This study gives an insight of ocular biometrics, corneal astigmatism and common IOL powers in this sample. A larger sample size study may project figures for entire Sri Lankan population.

THE PREVALENCE OF STRABISMUS AND ASSOCIATED REFRACTIVE ERRORS IN SCHOOL CHILDREN IN AKURE SOUTH LOCAL GOVERNMENT ONDO STATE

Associations between strabismus and refractive errors have been reported inprevious studies. The purpose of this study was to determine the prevalence andassociation of strabismus with refractive errors in school aged children between10?16 years. A total sample size of2600 subjects was employed for this study.Routine eye examinations were carried out on the subjects. Unilateral cover test wasused to detect the presence of strabismus while alternate cover test was used formeasurement of the deviation, thereafter objective and subjective refraction wasconducted on the strabismic subjects. Spearman coefficient correlation test wasused to check for relationship between strabismus and refractive errors. Theprevalence of strabismus in this study was 1.92%.The prevalence of esotropia andexotropia was 1.15% and 0.65% respectively, followed by hypertropia with aprevalence of 0.08% and hypotropia with a prevalence of 0.04%. All strabismicchildren (n=50) had refractive errors. The prevalence of astigmatism, hyperopia andmyopia was 1.27%, 0.35% and 0.31% respectively. There was positive correlationbetween strabismus and refractive errors, (P &lt; 0.05 and ?s was 0.63).Theprevalence of strabismus was low in this study. As the dioptric prism power ofstrabismus increased, the dioptric lens power of the refractive error also increased.Proper detection of refractive errors by eye care practitioners is key in themanagement of strabismus as high uncorrected refractive errors could lead todevelopment of strabismus.

Refractive status and optical components in premature infants with and without retinopathy of prematurity: A 4- to 5-year cohort study.

This study was aimed to investigate the characteristics of refractive parameters in premature infants and children aged 3-8 years with mild retinopathy of prematurity (ROP) and to explore the effects of premature delivery and mild ROP on the development of refractive status and ocular optical components. Premature infants who underwent ocular fundus oculi screening in our hospital between January 2009 and February 2011 were included and divided into the ROP group and the non-ROP group. Full-term infants were the controls. The results of the annual ocular examination conducted between 2014 and 2018 were analysed, and the refractive status, optical components, and developmental trends were compared among the three groups. The total follow-up time was 4-5 years. The prevalence of myopia and astigmatism was high in the ROP group (P < 0.05). In the non-ROP group, the prevalence of myopia was also higher than that in the control group. The prevalence of myopia increased with age in the ROP and non-ROP groups, while the prevalence of astigmatism remained unchanged. In the ROP group, the corneal refractive power was the largest, the lens was the thickest and the ocular axis was the shortest; in the control group, the corneal refractive power was the smallest, the lens was the thinnest, and the ocular axis was the longest. These parameters in the non-ROP group were between those in the two groups mentioned above (P < 0.05). The corneal refractive power was relatively stable at 3-8 years old in the three groups. The change in lens thickness was small in both the ROP group and the non-ROP group (P = 0.75, P = 0.06), and the lens became thinner in the control group (P < 0.001). The length of the ocular axis increased in the three groups. Preterm infants are more likely to develop myopia than full-term infants, and children with ROP are more likely to develop both myopia and astigmatism. Thicker lenses were the main cause of the high prevalence of myopia in premature infants with or without ROP.

Prevalence of astigmatism in school going children: a hospital-based study at Majeedia Hospital, New Delhi

Background: Generally, astigmatism is type of refractive error due to distorted and irregular of the cornea. It’s generally related to the cornea and lens.Methods: This is cross-sectional study conducted over a period from January 2017 till April 2017 among the patients in HAHC hospital. A comprehensive eye examination was used to analyse the refractive error (astigmatism). And the research was approved by the institutional review board and the ethics committee for at department of paramedical sciences, Jamia Hamdard New Delhi India.Results: A total of 90 patients were included in the study. Out of which 37 were boys and 52 were girls. The rate of myopic astigmatism increased with age. In contrast, the rate of hyperopic and mixed astigmatism decreased with age. In addition, the rate of with-the-rule astigmatism increased and the rate of against-the-rule decreased with respect to age, but oblique astigmatism was rather stable with age.Conclusions: There was more myopic astigmatism and with-the-rule astigmatism in total of 90 patients. Our hospital-based study shows there are high percentage of astigmatism (47.8%) in school aged children in south Delhi region. It is important to study in future, to further evaluate the causes and magnitude of astigmatism and increase awareness among school going children in South Delhi.

Rural-urban differences in prevalence of and risk factors for refractive errors among school children and adolescents aged 6-18 years in Dalian, China.

PurposeTo assess the prevalence of refractive errors (REs) in school children aged 6–18 years in urban and rural settings in Dalian, Northeast of China.MethodsThis is a school-based cross-sectional survey using multi-stage randomization technique. Six- to eighteen-year-old school children from elementary schools, junior and senior high schools from a rural area and an urban area in Dalian were included in December 2018. All subjects underwent a comprehensive questionnaire and eye examination.ResultsA total of 4,522 school children with 6–18 years of age were investigated. The age, gender-adjusted prevalence of myopia, and anisometropia were 82.71 and 7.27% among the urban students as compared to 71.76% and 5.41% among the rural ones (OR = 1.80, 95 % CI = 1.53 - 2.11, P < 0.001; OR = 1.29, 95 % CI = 1.00–1.67, P = 0.049), respectively. The hyperopia was less common in urban students than in rural ones (5.63 vs. 10.21%; OR = 0.54, 95 % CI: 0.43–0.67, P < 0.001). However, there was no significant difference in prevalence of astigmatism between urban (46.07%) and rural (44.69%) participants (OR = 0.96, 95 % CI: 0.84–1.10, P = 0.559). The differences on prevalence of REs were attributed to different social-demographic and physiologic factors.ConclusionsThe students from urban settings are more likely to have myopia and anisometropia but less likely to have hyperopia than their rural counterparts. Although considerable attention had been paid to controlling REs, it is necessary to further consider the urban-rural differences in REs.

Astigmatism profile in the elderly population: Tehran Geriatric Eye Study

To determine the prevalence of astigmatism and its associated factors and examine astigmatism symmetry patterns in an elderly population. Population based cross-sectional study. The present population-based cross-sectional study was conducted on an elderly population above 60 years of age in Tehran, Iran in 2019. The sampling was done using the stratified multistage random cluster sampling method. All study participants underwent a complete optometric examination and slit-lamp biomicroscopy. The prevalence of astigmatism higher than -0.50, -1.00, and -2.00 D was 83% (95% CI: 81 -84), 52 % (95% CI: 50 -54), and 19% (95% CI: 17-20), respectively. These prevalence was 79%(95% CI: 77-81), 46(95% CI: 44-49) and 14(95% CI: 13-16) in subjects without a history of ocular surgery, respectively. Based on cylinder power worse than -1.00 D, 10% (95% CI: 9-12), 20% (95% CI: 18-22), and 21% (95% CI:19-23) of study participants had with the rule, against the rule, and oblique astigmatism, respectively. According to the results of the multiple regression model, male gender, older age, low education level, pure posterior subcapsular cataract, pseudophakia, and myopia were independent factors associated with astigmatism. The prevalence of anisorule astigmatism was 57 % (95% CI: 56-59), the most common anisorule astigmatism was against the rule-oblique type with a prevalence of 36% (95% CI: 34-38). The prevalence of astigmatism was high in the elderly population of Tehran. More than half of the participants in this study had anisorule astigmatism, and against the rule-oblique combination was more prevalent than other types. A posterior subcapsular cataract, a history of cataract surgery, and myopia were the associated factors of astigmatism in this study.

Структура распространенности врожденного астигматизма слабой степени

Purpose. To evaluate structure of low degree congenital astigmatism prevalence. Material and methods. A retrospective analysis of the biometric parameters of 128,379 patients (256,630 eyes) who underwent diagnostic or treatment care in S. Fyodorov Eye Microsurgery Federal State Institution from 2013 to 2018 was carried out. All results of routine examination were evaluated, including best non-corrected visual acuity and best corrected visual acuity, central corneal thickness and lens thickness, anterior chamber depth, biometry. Results. The structure of congenital astigmatism over the studied period was distributed as follows: astigmatism of more than 1.0 D was diagnosed in 66,610 (25.96%) eyes. The main number of patients had low degree astigmatism – 86.30%, with the rule astigmatism – 56.10%. Simple astigmatism was diagnosed in 5,317 (7.98%) eyes, complex in 52,436 (78.72%) eyes. The most frequent combination of astigmatism was with myopic refraction 40,955 (61.48%), the least with emmetropic 5,317 (7.98%). Conclusions. Patients with corneal astigmatism mostly underwent cataract surgery 10 years earlier than emmetropic patients, still at working age, due to the inability to engage in professional activities. Most of them were female. Astigmatism up to 0.75 D is more common on the right dominant eye, from 2.0 D and more on the left. All the correlation coefficients indicate a barely noticeable relationship between biometric parameters and the degree of astigmatism. Key words: astigmatism, congenital astigmatism, corneal pathology