Prevalence and pattern of refractive error and visual impairment among schoolchildren: the Lhasa childhood eye study

Abstract Background Early and effective ocular screening may help to eliminate treatable eye disorders. The Lhasa Childhood Eye Study (LCES) revealed the particular prevalence of refractive error and visual impairment in grade one schoolchildren (starting age of 6 years old) in Lhasa. Methods This is a cross-sectional part of school-based cohort study. One thousand nine hundred forty-three children were enrolled (median age, 6.78 years, range, 5.89 to 10.32). Each child underwent general and ocular examinations, including logarithm of the minimum angle of resolution (logMAR) visual acuity, cycloplegic autorefraction, and slit-lamp biomicroscopy evaluation. Multivariate and correlation analyses were performed to evaluate the association between refractive error with gender and ethnics. Results The prevalence of visual impairment (logMAR visual acuity ≥0.3 in the better-seeing eye) of uncorrected, presenting and best-corrected visual acuity (BCVA) was 12.2, 11.7 and 2.7%, respectively. Refractive error presented in 177 (78.0%) out of 227 children with bilateral visual impairment. Myopia (spherical equivalent refractor [SER] ≤ − 0.50 diopter [D] in either eye) was present in 4.7% children when measured after cycloplegic autorefraction. Hyperopia (SER ≥ + 2.00 D) affected 12.1% children. Hyperopia was significantly associated with female gender (P<0.001). Astigmatism (cylinder value ≤ − 0.75 D) was present in 44.8% children. In multivariate regression and correlation analysis, SER had no significant difference between ethnic groups. Conclusion The Lhasa Childhood Eye Study is the first school-based cohort study to reveal the prevalence and pattern of refractive error and visual impairment in Lhasa. Effective strategies such as corrective spectacles should be considered to alleviate treatable visual impairment.

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Prevalence and associated risk factors for childhood strabismus in Lhasa, Tibet, China: a cross-sectional, school-based study

BMC Ophthalmology ◽

10.1186/s12886-020-01732-2 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Hailong He ◽

Jing Fu ◽

Zhaojun Meng ◽

Weiwei Chen ◽

Lei Li ◽

...

Keyword(s):

Risk Factors ◽

Risk Factor ◽

Primary Schools ◽

Clinical Trial Registry ◽

Cross Sectional ◽

Link Type ◽

School Based ◽

Significant Difference ◽

Associated Risk Factors ◽

Grade One

Abstract Background To estimate the prevalence of strabismus and associated risk factors among grade one school children in Lhasa, Tibet, China. Methods The Lhasa Childhood Eye Study (LCES) was a cross-sectional, school-based childhood study conducted in Grade one students from primary schools in Lhasa, Tibet, China. Comprehensive ophthalmic examinations and basic systemic examinations were evaluated. A questionnaire survey containing information about children, as well as parents’ information, was sent to the corresponding parents of eligible children. The prevalence of strabismus and its 95% confidence interval was estimated. Univariate and multivariate logistic regression analyses were conducted to determine the associated risk factors. Results A total of 1942 eligible grade one students were enrolled, of which 1856 participants completed all examinations. The average age was 6.83 ± 0.46 years, 53% of participants were boys and 1762 were the Tibetan Minority. Over all, the prevalence of strabismus was 68/1856 (3.7%) (95%CI: 2.81,4.52), with no difference between the ages, genders, ethnicities and body mass index, while tilting one’s head when writing may be a risk factor for strabismus (P = 0.004). Strabismus students had mean best corrected visual acuity of 0.16 ± 0.28(LogMAR), over 50% patients with esotropia were hyperopic, and participants who had stereopsis impairments showed a significant difference between esotropia and exotropia (P = 0.026). Conclusions The prevalence of strabismus in LCES was 3.7%, which is higher than previous reports from Chinese childhood epidemiology studies. Strabismus is a common contributing factor to amblyopia. Tilting one’s head when writing may be a risk factor. Esotropia is more likely to affect stereopsis and be associated with the refractive state of hyperopia. Trial registration The study has finished the clinical registration on Chinese Clinical Trial Registry. (http://www.chictr.org.cn, ChiCTR1900026693).

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Study on visual function comparison between ametropes and emmetropes after visual correction

Indian Journal of Clinical and Experimental Ophthalmology ◽

10.18231/j.ijceo.2021.085 ◽

2021 ◽

Vol 7 (2) ◽

pp. 428-432

Author(s):

L K Lali ◽

R Abirama Sundari ◽

R Shankar

Keyword(s):

Visual Acuity ◽

Contrast Sensitivity ◽

Refractive Error ◽

Axial Length ◽

Reading Speed ◽

Cross Sectional Study ◽

Cross Sectional ◽

Visual Functions ◽

Significant Difference

Studies had also shown that 86% of children with refractive error living in rural area are without correction as many are unaware of their problem. Refractive error by itself plays a significant role on one’s quality of life and literature had also proven it. To study the visual functions in ametropes with 6/6 BCVA and compare it with emmetropes.: A cross-sectional study was conducted for a period of one year. All the 200 subjects were tested for refractive error using auto refractor, distance and near visual acuity was assessed with the ETDRS chart, contrast sensitivity was assessed using LEA symbol chart, color vision was assessed using FM 15 online test and field vision was tested using Bjerrum tangent screen, stereopsis was examined using TNO cards, morphometric measurements was done by measuring the axial length using A scan and the K reading was obtained using auto keratometer and finally the functional assessment was analysed using the reading and writing speed. A total of 200 subjects with 100 ametropes and 100 emmetropes were included in our study. Colour vision, near point accommodation, near point convergence, axial length were significantly altered in ametropes. Contrast sensitivity, steropsis and reading speed were significantly reduced in ametropes compared to emmetropes. There was no significant difference in visual functions between different types refractive error subjects like myopia, hypermetropia and astigmatism. The present study proves that visual acuity alone is not an indicator for assessing the quality of vision instead the complete visual functions has to be screened on all patients reporting with refractive error.

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Prevalence and associated risk factors for childhood strabismus in Lhasa, Tibet, China: a cross-sectional, school-based study

10.21203/rs.3.rs-27963/v2 ◽

2020 ◽

Author(s):

Hailong He ◽

Jing Fu ◽

Zhaojun Meng ◽

Weiwei Chen ◽

Lei Li ◽

...

Keyword(s):

Risk Factors ◽

Risk Factor ◽

Primary Schools ◽

Cross Sectional ◽

School Based ◽

Significant Difference ◽

The Mean ◽

Associated Risk Factors ◽

Grade One ◽

Epidemiology Studies

Abstract Background: To estimate the prevalence of strabismus and associated risk factors among grade one school children in Lhasa, Tibet, China.Methods: The Lhasa Childhood Eye Study (LCES) was a cross-sectional, school-based childhood study conducted in Grade one students from primary schools in Lhasa, Tibet, China. Comprehensive ophthalmic examinations and basic systematic examinations were evaluated. A questionnaire survey contained information about children, as well as parents’ information was sent to the corresponding parents of eligible children. The prevalence of strabismus and its 95% confidence interval was estimated. Univariate and multivariate logistic regression analyses were conducted to determine the associated risk factors.Results: A total of 1942 eligible grade one students were enrolled, of which 1856 participants completed all procedures. The average age was 6.83±0.46 years, 53% of participants were boys and 1762 were the Tibetan Minority. Over all, the prevalence of strabismus was 68/1856(3.7%) (95%CI: 2.81,4.52), with no difference between the ages, genders, ethnics and BMI, while tilt one's head when writing may be a risk factor for strabismus (P=0.004). Strabismus students had the mean best corrected visual acuity 0.16±0.28(LogMAR), over 50% patients with esotropia are hyperopia, participants who have stereopsis impairments showed a significant difference between esotropia and exotropia (P=0.026).Conclusions: The prevalence of strabismus in LCES was 3.7%, higher than previous reports from Chinese childhood epidemiology studies. Strabismus is a common contributing factor to amblyopia. Tilt one's head when writing may be a risk factor. Patients with esotropia are more likely to affect stereopsis and be the refractive state of hyperopia.

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Prevalence of visual impairment and refractive error in school-aged children in South Darfur State of Sudan

African Vision and Eye Health ◽

10.4102/aveh.v75i1.355 ◽

2016 ◽

Vol 75 (1) ◽

Cited By ~ 2

Author(s):

Saif H. Alrasheed ◽

Kovin S. Naidoo ◽

Peter C. Clarke-Farr

Keyword(s):

Visual Impairment ◽

Refractive Error ◽

Primary Schools ◽

Anterior Segment ◽

Care Plan ◽

Cluster Sampling ◽

Cross Sectional ◽

School Aged Children ◽

Grade Levels ◽

Significant Difference

Background: Global estimates suggest there are almost 19 million visually impaired children worldwide, the major cause being uncorrected refractive error (RE).Aim: To assess the prevalence of visual impairment (VI) and RE among Sudanese school-aged children.Setting: Eight randomly selected primary schools from 21 districts in South Darfur State of Sudan were involved.Methods: A school-based cross-sectional study of RE and VI in primary schoolchildren from grades 1 to 8 (children aged 6–15 years) was investigated. A Refractive Error Study in Children (RESC) protocol was implemented to determine the prevalence of RE and VI in these schoolaged children. Participants were enrolled through stratified multistage cluster sampling of four all-male and four all-female primary schools from South Darfur State of Sudan. Examination procedures followed the RESC protocol, which included visual acuity (VA) measurements, binocular vision assessments, retinoscopy and autorefraction under cycloplegia, as well as examination of the external eye, anterior-segment, media and fundus.Results: A total of 1775 children were invited to participate in the study and 1678 were examined resulting in a participation rate of 94.5%. The findings indicated that the prevalence of uncorrected, presenting and best-corrected VA of 6/12 or worse was 6.4% (95% confidence interval [CI], 4.9–7.9), 4.4% (95% CI, 2.9–5.9) and 1.2% (95% CI, 0.3–2.7) respectively. RE was the cause of VI in 57% of participants, retinal disorders in 13.1%, amblyopia in 5.6%, corneal opacity in 0.9%, cataract in 3.7%, with the causes of reduced vision undetermined in 10.3% and various other causes contributed 9.3%. External and anterior-segment abnormalities were observed in 10.2% of children. This was mainly allergic conjunctivitis (5.3%) followed by bacterial and viral conjunctivitis (4.2%). The prevalence of myopia (≥|-0.50 D|) in one or both eyes was 6.8% (95% CI, 5.3–8.3), hypermetropia (≥ 2 D) was noted in 1.9% (95% CI, 0.4–3.4) and astigmatism (≥|-0.75 D|) prevailed in 2.5% (95% CI, 1.0–4.0). Prevalence of VI among schoolaged children were associated with the children’s age and grade levels (p = 0.00) but was not correlated with gender (p = 0.224). Prevalence of RE among school-aged children was significantly correlated with age and grade levels (p = 0.00). No significant correlation was found between gender and prevalence of RE (p = 0.833). The prevalence of VI because of myopia was associated with increasing grade levels and also the childhood age (p = 0.023), but there was no significant difference in the prevalence of VI because of myopia between male and female children.Conclusion: Uncorrected RE was a major cause of VI among children in the South Darfur State. There is thus a critical need for developing a comprehensive child eye care plan focusing on the reduction of uncorrected RE through collaboration between key stakeholders and government.

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The Prevalence and Causes of Visual Impairment among Children in Kenya – The Kenya Eye Study

10.21203/rs.3.rs-41148/v1 ◽

2020 ◽

Author(s):

Shadrack Muma ◽

Stephen Obonyo

Keyword(s):

Visual Acuity ◽

Visual Impairment ◽

World Health Organization ◽

Refractive Error ◽

Odds Ratio ◽

Population Based ◽

World Health ◽

Cross Sectional ◽

The World ◽

Health Organization

Abstract BackgroundVisual impairment impacts negatively on quality of life. Kenya has a total fertility rate of 3.5 an indication of more younger generation. However, little is known on the prevalence and causes of visual impairment in the children population of Kenya.MethodsThis cross-sectional population-based study included 3400 (1800, 52.9% female) randomly selected children with a mean age of 12 ± 2 years (range 5–16 years) in Kenya. Visual acuity was taken using snellens chart at 6 meters. Anterior and posterior segments were assessed using slit lamp and indirect ophthalmoscope. The World Health Organization formed the baseline for calculating prevalence of visual impairment.ResultsVisual acuity measurements were available for 3240 (95.3%) participants. The prevalence of visual impairment, based on pin-hole value, using World Health Organization, was 1.7 ± 0.3%. The prevalence of visual impairment, based on presenting visual acuity value, was 2.4 ± 0.7%, using the World Health Organization definition. Multivariate analysis demonstrated that the presence of visual impairment on pin-hole, according to World Health Organization definition increased significantly with increasing age (odds ratio 1.230, P = .021) and increased astigmatism (odds ratio 0.834, P = .032), but not significantly associated with socioeconomic, ocular conditions after adjusting for age and astigmatism. Lack of refractive error correction was the most common reason for presenting visual impairment. Causes of visual impairment due to presenting visual acuity were amblyopia (24%), nystagmus (14%), myopia (49%) and hyperopia (13%).ConclusionThe prevalence of visual impairment in Kenya increased significantly with socio-economic activities. Uncorrected refractive error remains the major causes of visual impairment.

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Violence and Mental Health among Adolescents in South East Nigeria

10.21203/rs.3.rs-551613/v1 ◽

2021 ◽

Author(s):

Maduka D Ughasoro ◽

Vivian Ozoemena Onukwuli ◽

Obinna E Onwujekwe ◽

Benjamin S.C Uzochukwu ◽

Bassey Ebenso ◽

...

Keyword(s):

Mental Health ◽

Female Gender ◽

P Value ◽

Cross Sectional ◽

Adolescent Violence ◽

School Based ◽

Significant Difference ◽

High Prevalence ◽

The Impact ◽

Structured Questionnaire

Abstract BackgroundThere is rise in the prevalence of mental health illnesses among the adolescent and the impact of violence on this rising trend requires to be evaluated. This is the aim of this study.Methods.The study was a cross-sectional school based study. Adolescents in the selected schools were interviewed using structured questionnaire. Information on the previous experience of violence, the action they took, and the effect on them were collected. Data was entered and analyzed using SPSS. Significant was set at the p-value of <0.05.ResultsA total of 716 adolescents were involved in the study. The prevalence of violence was 87%. About 57.2% of the violence occurred at home, 44.2% done by relatives and 49.2% within the past 6 months. Sexual abuse was 10.2%. Among the adolescents that experienced violence, 58.7% suffered some form of mental health illness(es). There was significant difference between the action the adolescents took after the violence incident and the action their considered appropriate (p=0.00001). Female gender (p=0.042), not living with parents (p=0.015) and poverty (p=0.00001) significantly correlate with adolescent violence.Discussion and Conclusion.Violence is high among adolescent and associated with high prevalence of mental health illnesses. Intervention to reduce violence should target improvement in poverty alleviation programs to empower families to carter for their children should be implemented.

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Prevalence and associated risk factors for childhood strabismus in Lhasa, Tibet, China: a cross-sectional, school-based study

10.21203/rs.3.rs-27963/v3 ◽

2020 ◽

Author(s):

Hailong He ◽

Jing Fu ◽

Zhaojun Meng ◽

Weiwei Chen ◽

Lei Li ◽

...

Keyword(s):

Risk Factors ◽

Risk Factor ◽

Primary Schools ◽

Clinical Trial Registry ◽

Cross Sectional ◽

School Based ◽

Significant Difference ◽

Associated Risk Factors ◽

Grade One ◽

Epidemiology Studies

Abstract Background: To estimate the prevalence of strabismus and associated risk factors among grade one school children in Lhasa, Tibet, China.Methods: The Lhasa Childhood Eye Study (LCES) was a cross-sectional, school-based childhood study conducted in Grade one students from primary schools in Lhasa, Tibet, China. Comprehensive ophthalmic examinations and basic systemic examinations were evaluated. A questionnaire survey containing information about children, as well as parents’ information, was sent to the corresponding parents of eligible children. The prevalence of strabismus and its 95% confidence interval was estimated. Univariate and multivariate logistic regression analyses were conducted to determine the associated risk factors.Results: A total of 1942 eligible grade one students were enrolled, of which 1856 participants completed all examinations. The average age was 6.83±0.46 years, 53% of participants were boys and 1762 were the Tibetan Minority. Over all, the prevalence of strabismus was 68/1856 (3.7%) (95%CI: 2.81,4.52), with no difference between the ages, genders, ethnicities and body mass index, while tilting one's head when writing may be a risk factor for strabismus (P=0.004). Strabismus students had mean best corrected visual acuity of 0.16±0.28(LogMAR), over 50% patients with esotropia were hyperopic, and participants who had stereopsis impairments showed a significant difference between esotropia and exotropia (P=0.026).Conclusions: The prevalence of strabismus in LCES was 3.7%, which is higher than previous reports from Chinese childhood epidemiology studies. Strabismus is a common contributing factor to amblyopia. Tilting one's head when writing may be a risk factor. Esotropia is more likely to affect stereopsis and be associated with the refractive state of hyperopia. Trial registration: The study has finished the clinical registration on Chinese Clinical Trial Registry. (http://www.chictr.org.cn , ChiCTR1900026693).

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Prevalence and associated risk factors for childhood strabismus in Lhasa, Tibet, China: a cross-sectional, school-based study

10.21203/rs.3.rs-27963/v1 ◽

2020 ◽

Author(s):

Hailong He ◽

Jing Fu ◽

Zhaojun Meng ◽

Weiwei Chen ◽

Lei Li ◽

...

Keyword(s):

Risk Factors ◽

Risk Factor ◽

Primary Schools ◽

Clinical Trial Registry ◽

Cross Sectional ◽

School Based ◽

Significant Difference ◽

Associated Risk Factors ◽

Grade One ◽

Epidemiology Studies

Abstract Background To estimate the prevalence of strabismus and associated risk factors among grade one school children in Lhasa, Tibet, China. Methods The Lhasa Childhood Eye Study (LCES) was a cross-sectional, school-based childhood study conducted in Grade one students from primary schools in Lhasa, Tibet, China. Comprehensive ophthalmic examinations and basic systematic examinations were evaluated. A questionnaire survey contained information about children, as well as parents’ information was sent to the corresponding parents of eligible children. The prevalence of strabismus and its 95% confidence interval was estimated. Univariate and multivariate logistic regression analyses were conducted to determine the associated risk factors. Results A total of 1942 eligible grade one students were enrolled, of which 1856 participants completed all procedures. The average age was 6.83 ± 0.46 years, 53% of participants were boys and 1762 were the Tibetan Minority. Overall, the prevalence of strabismus was 68/1856(3.7%) (95%CI: 2.81,4.52), with no difference between the ages, genders, ethnics and BMI, while tilt one's head when writing was a risk factor for strabismus (P=0.004). Strabismus students had the mean best corrected visual acuity 0.16 ± 0.28(LogMAR), over 50% patients with esotropia are hyperopia, participants who has stereopsis impairments showed a significant difference between esotropia and exotropia (P = 0.026). Conclusions The prevalence of strabismus in LCES was 3.7%, higher than previous reports from Chinese childhood epidemiology studies. Strabismus is a common contributing factor to amblyopia. Tilt one's head when writing was a risk factor. Patients with esotropia are more likely to affect stereopsis and be the refractive state of hyperopia. Trial registration: The study has finished the clinical registration on Chinese Clinical Trial Registry. (http://www.chictr.org.cn, ChiCTR1900026693).

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Prevalence and associated risk factors for childhood strabismus in Lhasa, Tibet, China: a cross-sectional, school-based study

10.21203/rs.3.rs-27963/v4 ◽

2020 ◽

Author(s):

Hailong He ◽

Jing Fu ◽

Zhaojun Meng ◽

Weiwei Chen ◽

Lei Li ◽

...

Keyword(s):

Risk Factors ◽

Risk Factor ◽

Primary Schools ◽

Cross Sectional ◽

School Based ◽

Significant Difference ◽

The Mean ◽

Associated Risk Factors ◽

Grade One ◽

Epidemiology Studies

Abstract Background: To estimate the prevalence of strabismus and associated risk factors among grade one school children in Lhasa, Tibet, China. Methods: The Lhasa Childhood Eye Study (LCES) was a cross-sectional, school-based childhood study conducted in Grade one students from primary schools in Lhasa, Tibet, China. Comprehensive ophthalmic examinations and basic systematic examinations were evaluated. A questionnaire survey contained information about children, as well as parents’ information was sent to the corresponding parents of eligible children. The prevalence of strabismus and its 95% confidence interval was estimated. Univariate and multivariate logistic regression analyses were conducted to determine the associated risk factors. Results: A total of 1942 eligible grade one students were enrolled, of which 1856 participants completed all procedures. The average age was 6.83±0.46 years, 53% of participants were boys and 1762 were the Tibetan Minority. Over all, the prevalence of strabismus was 68/1856(3.7%) (95%CI: 2.81,4.52), with no difference between the ages, genders, ethnics and BMI, while tilt one's head when writing may be a risk factor for strabismus ( P =0.004). Strabismus students had the mean best corrected visual acuity 0.16±0.28(LogMAR), over 50% patients with esotropia are hyperopia, participants who have stereopsis impairments showed a significant difference between esotropia and exotropia ( P= 0.026). Conclusions: The prevalence of strabismus in LCES was 3.7%, higher than previous reports from Chinese childhood epidemiology studies. Strabismus is a common contributing factor to amblyopia. Tilt one's head when writing may be a risk factor. Patients with esotropia are more likely to affect stereopsis and be the refractive state of hyperopia.

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Epidemiological Findings of Refractive Errors and Amblyopia among the Schoolchildren in Hatta Region of the United Arab Emirates

Dubai Medical Journal ◽

10.1159/000512521 ◽

2021 ◽

pp. 1-7

Author(s):

Salam Chettian Kandi ◽

Hayat Ahmad Khan

Keyword(s):

Visual Acuity ◽

Visual Field ◽

United Arab Emirates ◽

Refractive Error ◽

Screening Program ◽

Low Vision ◽

Refractive Errors ◽

Vision Screening ◽

Screening Programs ◽

School Based

Introduction: Uncorrected refractive errors and amblyopia pose a major problem affecting schoolchildren. We had previously observed that many schoolchildren in the Hatta region presented to the ophthalmology clinic with uncorrected refractive errors and amblyopia, which led us to undertake this research. As per the WHO, the term “visual impairment” can be “low vision” or “blindness.” Based on the presenting vision, “low vision” is defined for children who have vision of <6/18 to 3/60 or having visual field loss to <20° in the better-seeing eye. Children defined to have “blindness” have presenting vision of <3/60 or corresponding visual field of <10°. Purpose: To estimate the magnitude of uncorrected refractive errors and amblyopia among the schoolchildren aged 6–19 years and to assess the efficacy of school-based refractive error screening programs in the Hatta region of the United Arab Emirates. Methods: An epidemiological, cross-sectional, descriptive study was conducted on the entire student population studying in the government schools of the region. Those who failed the Snellen visual acuity chart test and those who were wearing spectacles were evaluated comprehensively by the researcher in the Department of Ophthalmology of the Hatta Hospital. Data were entered in the Refractive Error Study in School Children (RESC) eye examination form recommended by the WHO, and were later transferred to Excel sheets and analyzed by SPSS. Results: 1,591 students were screened and evaluated from the end of 2016 to mid-2017. About 21.37% (n = 340) had impaired vision with 20.9% (n = 333) refractive errors, of which 58% were uncorrected. Among the refractive error group, 19% (64 subjects) had amblyopia (4% of total students). The incidence of low vision was 9.5% and blindness was 0.38%. Low vision was found to be 9.5% and blindness 0.38%, taking in to account presenting visual acuity rather than best-corrected visual acuity for defining low vision and blindness. Conclusion: A significant number of students were detected to have uncorrected refractive errors among the vision impaired group (59%, n = 197) despite a school-based vision screening program in place. Seventy-eight percent of the amblyopia cases (n = 50) were found to be in the 11–19 years age group. Noncompliance with optical corrections was the reason for the high number of cases. A rigorous vision screening program and refractive services, complimented with awareness among parents and teachers, are recommended.

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