Comparison of visual acuity and ocular symptoms among computer users and non-users in young adults in Lucknow

Background: The multitude of ocular health problems has raised in recent times due to increased use of computers. Aims and Objectives: This study aims to compare the visual acuity and ocular symptoms between computer users and non-users among young adults in Lucknow. Materials and Methods: This case-control study was conducted on 370 students after obtaining Ethical Committee approval. Samples were collected using convenience sampling as per inclusion and exclusion criteria. In a validated self-administered questionnaire, demographic information, computer usage patterns, and accompanying visual symptoms were documented. Values of parameter were collected using Snellen’s chart. Statistical Package for the Social Sciences, 16.0 version was used for data analysis. Two sample t test will be used to relate between the quantitative variables. Results: A total of 370 study subjects were included in this study. About, majority of the participants (54%) were males, the participants were males accounting for a total of 54%. The age of the participants ranged from 15 to 40 years with a mean of 26.86 years. Average uses of screen time by computer user and non-user were 2.30 ± 0.90 and 10.60 ± 0.75, respectively. About 39% students suffering with eye strain which was major ocular symptom in the study followed by 30.8% watery eye. Conclusion: This study concludes that the use of a computer for an extended period of time without any physical activity can lead to eyesight problems and lower efficiency.

Prevalencia de baixa acuidade visual em escolares / Prevalence of visual disorders in school children

Resumo Objetivo: Avaliar o perfil epidemiologico de disfuncao da acuidade visual (AV), possiveis disturbios oculares e a frequencia ao atendimento oftalmologico, de escolares do municipio de Itauna, Minas Gerais, Brasil. Posteriormente objetivou-se o encaminhamento ao especialista para correcao das anormalidades. Métodos: Estudo transversal, com populacao avaliada de 432 alunos da rede publica de ensino. Os individuos foram avaliados pelo metodo Snellen e a faixa etaria da amostra variou de 4 a 17 anos. Os dados foram colhidos e sistematizados. Foram encaminhados para o servico de Oftalmologia aqueles que possuiam AV ≤ 0,7 em pelo menos um dos olhos. Resultados: Dos 432 alunos avaliados neste estudo 14,5% apresentaram baixa AV, quando avaliados pelo teste de Snellen. Destes, 61,9 % pertenciam ao sexo feminino. A faixa etaria em que houve maior prevalencia de baixa visao foram escolares de 15 a 17 anos. A maioria apresentou alteracao em ambos os olhos e 60% dos alunos avaliados declararam nunca terem passado por uma consulta oftalmologica. Dos alunos que compareceram as consultas, a maioria foi diagnosticada com erros de refracao e necessitou de correcao otica. Conclusão: Os resultados encontrados demonstram que a parcela significativa dos individuos avaliados apresentou baixa visao e necessitou de encaminhamento oftalmologico. Alem disso, observou-se a inexistencia de consultas oftalmológicas anteriores em grande parte dos escolares. Esse fato reforca, diante dos orgaos publicos de saude, a necessidade de implantar sistemas de triagem visual nas escolas e oferecer assistencia a esses estudantes, objetivando melhorias em seu aprendizado e qualidade de vida.

ABSTRACT Objective: To evaluate the epidemiological profile of visual acuity (VA) dysfunction, the possible ocular disorders and the frequency of ophthalmologic care of school children from the city of Itaúna, Minas Gerais, Brazil. Methods: A cross-sectional study with a population of 432 students in the public schools. The individuals were evaluated by the Snellen method and the sample age ranged from 4 to 17 years. Data were collected and systematized. Those who had VA ≤ 0.7 in at least one eye were referred to the ophthalmology service. Results: Of the 432 students evaluated in this study, 14.5% presented low VA, when evaluated by the Snellen test. Of these, 61.9% were female. The age group with the highest prevalence of low vision were schoolchildren aged 15 to 17 years. The majority presented alteration in both eyes and 60% of the evaluated students stated that they had never had an ophthalmological consultation. Of the students who attended the consultations, most were diagnosed with refractive errors and needed optical correction. Conclusion: The results showed that a significant portion of the individuals evaluated had low vision and required ophthalmologic referral. In addition, there was no previous ophthalmological consultation in most of the schoolchildren. This fact reinforces to public health agencies, the need to implement visual screening systems in schools and offer assistance to these students, with the aim of improvements in their learning and quality of life

Triagem oftalmológica e análise dos potenciais fatores de risco para a baixa acuidade visual de alunos no Ensino Fundamental I (primeira a quarta série) da rede pública em Alfenas/MG (Brasil) / Ophthalmologic screening and analysis of potential risk factors for the low visual acuity in children from first to fourth grade attending Alfenas City/MG (Brazil) public elementary schools

Objetivos: Neste estudo foi realizada uma triagem oftalmológica em crianças matriculadas em duas escolas (1ª a 4ª série) da rede pública de ensino no município de Alfenas ­ MG (Brasil), posteriormente relacionando a baixa acuidade visual (AV) com fatores de risco. Metodologia: Este é um estudo transversal no qual a AV foi avaliada por meio do teste de Snellen e questionários foram respondidos pelos pais e professores das crianças que apresentaram alterações da AV. Resultados: Foram avaliadas 764 crianças (n = 764, 52% do sexo feminino; IC(95%) 48-55%) de 6 a 10 anos de idade, tendo sido observado que 97 delas (13%; IC(95%) 10-15%) apresentaram alguma alteração na AV e, dentre as 97, 53% (IC(95%) 43-63%) foram do sexo masculino. Não houve relação entre a prevalência de baixa AV e sexo da criança (χ² com p>0,05). O teste exato de Fisher revelou que a alta percentagem de crianças que nunca realizaram um exame oftalmológico teve uma significativa relação com a baixa AV (p<0,0001). 30% das crianças alegaram aos pais "enxergar bem" (autopercepção da visão), apesar de apresentarem baixa AV, indicando que a simples falta do parâmetro de comparação para a percepção de problemas na AV torna as triagens oftalmológicas essenciais nesta faixa etária. Em entrevista com professores, foi verificado haver uma infra-estrutura inadequada no sistema educacional e dificuldades para satisfazer as necessidades básicas educacionais de crianças com problemas visuais, bem como para identificar alterações na AV dos alunos e propiciar promoção de saúde no espaço escolar. Conclusão: Neste estudo a prevalência de baixa AV foi 13%, assim, é destacada a importância de uma triagem oftalmológica em crianças em idade pré-escolar e escolar visando o diagnóstico precoce dos problemas de visão e posterior esclarecimento e tratamento, possibilitando os desenvolvimentos social e cognitivo normais dos estudantes.

Aims: In this study, an ophthalmologic screening was performed in children attending two public schools (from 1st to 4th grade) in Alfenas city/MG (Brazil), and later correlated low visual acuity (VA) with risk factors. Methodology: This is a cross-sectional study, in which the VA was evaluated through the Snellen test and the parents and teachers of the children who presented alterations then answered questionnaires. Results: A total of 764 children (n = 764, 52.0% were females; CI(95%) 48.0-55.0%) from 6 to 10 years of age were evaluated, with 97 (13.0%; CI(95%) 10.0-15.0%) suffering impairment in the VA; of these, 53.0% (CI(95%) 43.0-63.0%) were males. The prevalence of low VA in male and female children was statistically the same (χ² with p>0.05). The Fisher test evidenced that the higher percentage of children who had never ever performed an ophthalmologic examination had a significant relation with low VA (p<0.0001). To 30% parents' awareness, the children claimed "see well" (despite they present low VA, as detected here), indicating that the simple lack of a comparison parameter for the perception of visual impairments makes ophthalmologic screening essential in this age group. In an interview with teachers, the respondents reported an inadequate infrastructure in the educational system and difficulties to satisfy the basic educational needs of children with sight problems, as well as to identify alterations in the VA of them, and to afford health promotion at schools. Conclusion: We reported that the prevalence of low VA was 13% accordingly is highlighted the importance of ophthalmologic screening of school-age children is highlighted, aiming at the early detection of eye problems in childhood and subsequent clarification and treatment, making possible a normal social and cognitive development of the students.

Reproducibilidad y concordancia para la carta snellen y lea en la valoración de la agudeza visual en infantes de primaria / Test-retest reliability and agreement for snellen and lea visual chart to assessment visual acuity in elementary school children

Introducción: la evaluación de la visión de un infante se determina empleandolas cartas de agudeza visual, aunque se les conoce comúnmente con el nombre de “optotipos”, de las cuales la más frecuentemente empleada es la Snellen.Objetivo: determinar la reproducibilidad inter observadores y la concordancia dedos test que miden la agudeza visual en infantes escolares. Materiales y métodos: se evaluaron 61 niños (122 ojos) visualmente sanos conedades entre los 6 a10 años de un colegio de la ciudad de Pereira. La agudeza visual (AV) fue valorada con una carta Snellen de letras y con una carta LEA por parte de dos evaluadores independientemente. Resultados: la AV promedio fue de 0.0 unidades del logaritmo del mínimo ángulo de resolución (logMAR) (20/20) y la diferencia media entre los test fue -0.05 (IC95 porciento-0.064 a -0.037) logMAR; el coeficiente de reproducibilidad (COR) fue mejor parala carta LEA que Snellen (±0.08 y 0.12) superior a lo reportado en estudios previos (±0.15).Conclusión: la concordancia con el coeficiente de correlación intraclase mostró ser moderada (0.493) y los límites de acuerdo mostraron que había una mayor variación entre las mediciones para cuando la AV era más alta. Las cartas LEA y Snellen mostraron una buena reproducibilidad, no obstante la variabilidad en las mediciones entre ellas indica que no son pruebas intercambiables.

Introduction: the evaluation of the vision of an infant is determined using the visual acuity charts, although they are commonly referred to as the “optotypes”, of which the most frequently used is the Snellen.Objetive: to determinate test retest reliability and the agreement of two tests used to assess elementary school children visual acuity. Methods: we evaluated 61 visual healthy children (122 eyes) ages 7 through 10enrolled in elementary school of Pereira. Visual acuity (VA) was measured with Snellen letters chart and LEA symbols chart by two evaluators.Results: the average of VA was 0.0 of logarithm of minimum angle of resolution(logMAR), the mean difference between the test was -0.05 (CI95% -0.064 to -0.037) logMAR; the coefficient of repeatability (COR) was better for LEA symbols and Snellen chart (±0.08 and 0.12) than those reported in previous papers (±0.15). Conclusion: the coefficient correlation Intraclass (CCI) has indicated a moderateconcordance (0.493) and the 95% limits of agreement showed a wider difference between the both charts measurements as while visual acuity was better. LEA symbols and Snellen chart have showed good test retest reliability, although the variability between both measurements indicates that they are not interchangeabletest.

Avaliação da acuidade visual na população atendida em 19 eventos nos anos de 2008 e 2009 em Presidente Prudente, SP / Assessment of visual acuity in 19 attended population events, during the years 2008-2009 in Presidente Prudente

JUSTIFICATIVA E OBJETIVOS: O déficit da acuidade visual (AV) gera importantes perdas na capacidade funcional e considerável morbidade aos seus portadores. Seu reconhecimento é de suma importância, uma vez que na maioria dos casos, tais deficiências podem ser corrigidas com a terapêutica adequada. O objetivo deste estudo foi identificar a porcentagem de pessoas que obtiveram acesso à consulta oftalmológica durante o último ano e a porcentagem das pessoas que utilizam lentes corretivas de forma satisfatória à Escala Optométrica de Snellen (EOS). MÉTODO: Foram realizados 19 eventos compreendendo as cidades de Presidente Prudente, Regente Feijó e Caiabú durante os anos de 2008 e 2009. Os entrevistados se dispuseram voluntariamente a participar da pesquisa, onde responderam o questionário proposto e o teste de Snellen. RESULTADOS: O grupo analisado foi composto por 1387 pessoas com idades entre 4 e 87 anos. Observou-se déficit visual em 54% dos participantes. Somente 16,8% afirmaram ter realizado consulta oftalmológica no último ano e 17% utilizavam lentes corretivas, embora somente 29,4% (5% da população) utilizassem a correção adequada. CONCLUSÃO: O déficit visual foi registrado na maioria da população avaliada atingindo todas as faixas etárias e sendo diretamente proporcional à idade. O estudo demonstrou que a maior parte dessa população não se submeteu à avaliação oftalmológica e dentre os que usavam lentes corretivas, grande parcela não o fazia de forma adequada.(AU)

BACKGROUND AND OBJECTIVES: The deficit of visual acuity (VA) generates important losses of functional capacities, and considerable morbidity to their carriers. Its recognition is of paramount importance, since in most cases, these deficiencies can be corrected with appropriate therapy. The objective of this study was identify the percentage of persons who had access to an ophthalmologic appointment during the last year and the percentage of people who used corrective lenses satisfactorily the Snellen Optometric Scale (SOS). METHOD: We conducted 19 events comprising the towns of Presidente Prudente, Regente Feijó and Caiabú during the years 2008 and 2009. Respondents were willing voluntarily to participate in the research, which complete the questionnaire and the Snellen test. RESULTS: The group was composed of 1387 people aged between 4 and 87 years. Observed visual deficit in 54% of participants. Only 16.8% said they had made an ophthalmologic appointment last year and 17% use corrective lenses, but only 29.4% (5% of the population) use the appropriate correction. CONCLUSION: The visual showed a majority in the population reaching all age groups and it is directly proportional to age. It seems that the population has no conscience of the need for prevention and use of appropriate corrective lenses. Ascertained that the minority of ophthalmologists consulted in advance, a great number does not buy or exchange their lenses as indicated. Most of the people know they don't see well, though they generally don't keep the need or don't have the means to achieve specialized treatment.(AU)

Prueba piloto para determinar la reproducibilidad de la carta de Snellen al evaluar la agudeza visual en sujetos jóvenes / Pilot trial to determine the reliability of the snellen chart for assessment of the visual acuity in young people

La agudeza visual es la principal característica evaluada para conocer cómo ve una persona. Al medirla se utilizan Cartas de Agudeza Visual, de las cuales la más empleada en el medio colombiano es la carta Snellen. Objetivo: el propósito de esta investigación fue determinar la reproducibilidad ínter e intraobservador de la carta de letras serif Snellen para evaluar la agudeza visual (AV). Materiales y métodos: en un muestreo por conveniencia, dos evaluadores midieron en dos sesiones la AV con la carta de Snellen tipo serif en 110 estudiantes universitarios (220 ojos) entre 15 y 30 años de edad, con ametropía corregida, visión binocular normal y sin patologías del segmento anterior o posterior. Se repitieron las pruebas en los pacientes induciendo una miopía de 1,50 D. Los valores de AV fueron convertidos de la escala fraccional a la logarítmica. Resultados: los resultados mostraron que la AV promedio (LogMAR) fue -0,06 (20/20+5); con la miopía inducida, 0,51 (20/63). La prueba de Wilcoxon pareada mostró diferencias significativas para la primera sesión entre los dos evaluadores (p = 0,0001; p = 0,007) y con el defecto inducido interevaluadores en las dos sesiones (p = 0,03; p = 0,001). El coeficiente de correlación y concordancia de Lin (Pc) indicó pobre concordancia (Pc = 0,9) ínter e intraobservador, sin defecto inducido y con éste. Los límites de concordancia de Bland-Altman muestran variaciones de AV de 3 líneas en los sujetos corregidos y de 5 a 6 líneas de visión con la miopía inducida. Conclusiones: la carta de Snellen presenta concordancia baja y variabilidad en los resultados moderada-alta, por lo que se sugiere la realización de estudios que evalúen la validez de la prueba en las poblaciones sana y con alteraciones visuales.

The visual acuity is the main characteristic evaluated to know how a person sees. For the visual acuity measuring it is used the letter chart, in Colombia the most used it is the Snellen Chart. Objective: To determinate the reliability inter e intraevaluator of Snellen Chart to test visual acuity. Methods: With convenience sampling two evaluators tested visual acuity with serif Snellen Chart to 110 subjects (220 eyes) who were university students between 15-30 years old, full distance refractive correction, normal binocular vision, and no pathologies of anterior and posterior of eye. A refractive error (myopia 1.50D) was induced for all the subjects and the trials were carrying out.Results: Visual acuity means was -0.06 (20/20+5), with induced myopia 0.51 (20/63). Wilcoxon sign rank test showed difference between inter evaluators (p=0,0001; p=0,007) in first trial and wearing plus lens +1.50D between inter evaluators in both trials ((p=0,03; p=0,001). Conclusions: Correlation Coefficient and Concordance of Lin showed a poor concordance and a moderated-high variability in the outcomes; then, Snellen chart has a poor concordance and moderate variability, so we suggest achieving researches about the validity of this test in the population with normal and subnormal vision.

Estudio comparativo de la agudeza visual tomada con el optotipo de Bailey Lovie y el optotipo de Snellen vs. angular de letras, en pacientes con ambliopía refractiva entre 5 y 12 años / Comparative study of visual acuity measure up to the bailey lovie chart chart vs. Chart of isolated letters in patients with refractive amblyopia between 5 and 12 years

Objetivo: determinar si existía una diferencia significativaen los resultados de agudeza visual medida con los optotipos de Snellen, Bailey Lovie y angular de letras en pacientes con ambliopía refractiva entre 5 y 12 años.Materiales y métodos: se realizó un estudio comparativode los resultados de agudeza visual medida con tres optotipos de visión lejana en 20 pacientes (40 ojos), entre 5 y 12 años, que asistieron a la Unidadde optometría pediátrica y entrenamiento visual del Instituto de investigaciones optométricas en el período comprendido entre febrero y abril del 2007, con diagnóstico confirmado de ambliopía refractivaResultados: el coeficiente de correlación de Pearson muestra una correlación más alta entre la agudeza visualtomada con el optotipo angular de letras y el optotipode Snellen (0,7200407), y una correlación más baja entre el optotipo de Snellen y el optotipo de Bailey Lovie (0,6425297). La prueba F de análisis de varianza muestra que existen diferencias significativas entre los valores de agudeza visual de cada optotipo (p < 0.05). La prueba de Dunnet (optotipo angular como control) mostró que hubo diferencias estadísticas entre los resultadosde la agudeza visual con Bailey (p < 0.05) y angular de letras. No hubo diferencias estadísticamentesignificativas con Snellen y angular (p > 0.05).Conclusiones: existe una alta correlación, sin diferenciassignificativas, entre los resultados obtenidos con los optotipos angular de letras y Snellen, debido probablemente a que utilizan las mismas letras, lo que favorece la tasa de memorización. Existe un gradobajo de correlación y una diferencia significativa entre la agudeza visual obtenida con los optotipos de Bailey Lovie y angular de letras. La diferencia entre la agudeza visual angular y morfoscópica es determinantea la hora de tomar la agudeza visual con el fin de diagnosticar el fenómeno de amontonamiento.

Objective: to determination if there are significant difference between the visual acuity results measured up to the Snellen chart , Bailey Lovie chart and chart of isolated letters in patients with refractive amblyopia between 5 and 12 years.Materials and methods: there was realized a comparative study of the results of visual acuity, measured up to three charts in far vision in 20 patients (40 eyes) by confirmed diagnosis of refractive amblyopia between 5 and 12 years, at the Unit of Pediatric Optometry and visual Training of the Optometric Research Institute of LaSalle University in the period between February and April, 2007.Results: the Pearson’s coefficient of correlation shows a higher correlation between the visual acuity taked with isolated letter chart and Snellen chart (0,7200407) and the lowest correlation between the Snellen and Bailey Lovie’s charts (0,6425297). In the variance analysis, there were significative differences between the values of visual acuity of each chart (p < 0.05). Dunnet’s test (isolated letter chart as control) shows that there was statistically significative difference between the results of Bailey’s chart and isolated letter chart (p < 0.05). There were not statistical differences the value of acute visual with Snellen VS isolated letter chart.Conclusions: There is a high correlation and there isn´t significative difference between isolated letter and Snellen chart, probably due to the fact that both of them use the same letters, which can lead to a high rate of memorization. There exists significative difference and low degree of correlation between visual acuity with Bailey Lovie’s chart and isolated letter chart. The difference between the angular and morphoscopic visual acuity is determinant at the moment of taking the visual acuity in order to diagnose the crowding phenomenon in this patients.

Correlation between Optokinetic Nystagmus Response and Visual Acuity

PURPOSE: The purpose of this paper was to determine the correlation between optokinetic nytagmus and grating and Snellen visual acuity charts and the validity of this correlation as an index. METHODS: Diffusion blur was used to cause visual decrease in 24 patients with normal eyes. Vision was measured using 3 different methods. To compare the central and peripheral vision, visiual acuity was measured using a macula occluder. RESULTS: Twenty four patients had an average uncorrected vision of 1.0 and showed regular visual acuity decrease using diffusion blur. Grating visual acuity showed correlation with the Snellen visual acuity but OKN visual acuity showed low correlation (p<0.05, ANOVA with repeated measure trend). OKN visual acuity showed low correlation with grating acuity when central visual acuity was occluded and only peripheral acuity was taken into consideration. CONCLUSIONS: Visual acuity measured using Snellen or grating acuity had little correlation with OKN visual acuity, and visual acuity measured using OKN was unable to indicate visual acuity in a quantitative manner.

The Effect of Diffusion Blur on Central and Peripheral Vision in Normal Adults

Diffusion blur, caused by liquid crystal windows, reduces contrast sensitivity and luminance, so visual acuity is decreased. Moreover, the windows' optical characteristics are similar to those of the cataractous lens. We measured the effect of liquid crystal window on central and peripheral visual acuity using Snellen and grating visual acuity charts. The subjects were 10 normal adults, therefore 20 eyes. We measured the voltage of the liquid crystal window at which the subjects could read the visual acuity chart through the liquid crystal window. In central vision, visual acuity was overestimated according to the Snellen chart, when compared to the results measured by those grating chart. But in peripheral vision, there were no differences between the two visual acuity charts. These results suggested that grating acuity has some limitations when used as a visual acuity test for cataractous patient. The ability of liquid crystal windows to cause diffusion blur suggests they could be used for foUowup observation in treatment of amblyopia or macular diseases.

Contrast Sensitivity Changes in Patients with Diabetic Retinopathy

Changes in contrast sensitivity have been demonstrated in patients with normal Snellen acuity. In an attempt to elucidate more sensitively the visual dysfunction before developement of either overt retinopathy or a reduction in Snellen acuity in patients with retinal disorders, contrast sensitivity test was performed in diabetic patients with normal Snellen acuity and control subjects matched for age and sex. The results were as follows. 1) Throughout all spatial frequencies(1.5 - 3.0 - 6.0 - 12.0 - 18.0 cpd), contrast sensitivity was significantly lower(P-value<0.01) in the diabetic eyes with retinopathy(30.7 - 49.3 - 52.5 - 16.1 - 7.8) than in the normal controls(42.5 - 84.3 - 103.0 - 60.5 - 25.1) or the diabetic eyes without retinopathy(43.1 - 92.2 - 95.8 - 43.4 - 16.4 ). 2) In high spatial frequencies(12.0 - 18.0 cpd) contrast sensitivity in the diabetic eyes without retinopathy group(43.4 - 16.4) was significantly decreased(P-value<0.01) in comparison with the normal controls(60.5 - 25.1). So, contrast sensitivity test is more sensitive test for central visual function than Snellen acuity.