Prevalence Of Visual Disorders Research Articles

Prevalence of Visual Disorders among Urban Palestinian Preschool Children

Background: Childhood blindness is a major public health concern since 40% of visual disorders that can cause blindness among children are preventable. Vision screening programs among preschool children have been implemented in several countries as a tool for early detection and intervention of visual disorders. In Palestine, there is a lack of scientific data on the prevalence of visual disorders among children. In addition, vision-screening programs that are currently implemented are neither validated nor effective. Objective: Using validated vision screening protocols, a cross-sectional study is conducted to determine the prevalence of visual disorders among urban Palestinian preschool children between the ages of 3 to 5 years in Nablus city. Methods: All children attending eight preschools selected using single-stage cluster sampling technique, underwent a validated vision screening administered by trained eye care professionals. The screening protocol was based on a combination of clinical assessment adopted from the Modified Clinical Technique and the Vision in Preschoolers studies, including assessment of visual acuity, ocular alignment, depth perception, color vision, non-cycloplegic retinoscopy, and ocular health. A pass-fail criterion was used to refer all children who did not attend the vision screening for comprehensive eye examination, including cycloplegic retinoscopy and a dilated fundus exam. A chi-squared test was used to determine any association between visual disorders and their independent risk factors. Results: A total number of 764 children underwent vision screening. Out of the 290 children who did not attend the vision screening, 127 children responded to the referral call for comprehensive eye examinations. Refractive error was the most prevalent visual disorder with a prevalence of (29.37%), followed by amblyopia (4.10%), color vision deficiency (1.24%), strabismus (1.24%), and ocular health abnormalities (0.70%). There was no age (p=0.35) and gender (p=0.32) variation in children having refractive errors. Anisometropia was the leading cause for amblyopia (1.32%, n=7), followed by significant refractive error (1.13%, n=6) and strabismus (0.37%, n=2). Conclusion: Refractive error was the most prevalent visual disorder affecting Palestinian preschoolers in Nablus. Anisometropia and significant refractive errors were found to be the major causes of amblyopia. Effective nationwide preschool vision screening programs should be implemented in Palestine to screen amblyogenic risk factors.

Towards seeing the visual impairments in Parkinson\u2019s disease: protocol for a multicentre observational, cross-sectional study

BackgroundVisual disorders are common in Parkinson’s disease (PD) but their exact frequency and severity are unknown. Good visual functioning is crucial for patients with PD, because of their need to compensate for loss of automated motor control and their postural instability, forcing patients to guide their movements visually. Here, we describe the study design of a cross-sectional, multi-centre study aiming to: (1) validate the Visual Impairment screening questionnaire (VIPD-Q, which aims to identify PD patients who should be referred to an ophthalmologist for further assessment); (2) study the prevalence of visual disorders in PD; (3) study the severity and clinical impact of different types of visual disorders in PD; and (4) explore treatment options for ophthalmologic disorders in PD, as a basis for future guideline development.MethodsThis study consists of two phases. In phase one, 750 PD patients and 250 healthy controls will be recruited to complete the VIPD-Q. In phase two, a subgroup of responders (n = 100) (with the highest and lowest scores on the VIPD-Q) will be invited for an extensive neurological and ophthalmological assessment. The in-depth ophthalmologic examination will serve as the “gold standard” for validating the VIPD-Q. Moreover, these assessments will be used to study associations between visual disorders and clinical presentation, in order to gain more insight in their clinical impact.DiscussionOur study will heighten the awareness of visual problems in PD and offers a robust starting point to systematically approach this subject. In current daily practice, the association between visual problems and PD is far from obvious to both patients and clinicians. Consequently, patients may not adequately report visual problems themselves, while clinicians miss potentially treatable visual disorders. Routinely asking patients to complete a simple screening questionnaire could be an easy solution leading to timely identification of visual problems, tailored treatment, restored mobility, greater independence and improved quality of life.Trial registrationDutch Trial Registration, NL7421, Registered on 4 December 2018 – Retrospectively registered.

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. Metodos: 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. Conclusao: 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 oftalmologicas 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.

The prevalence of visual disorders in Iranian students: A meta-analysis study and systematic review.

BackgroundVisual defects have dramatic effects on health, self-esteem, and educational function of students, and delayed diagnosis will cause complications, like academic failure and psychologic disorders.ObjectiveThe present study aimed to investigate the prevalence of ocular disorders in Iranian students in a systematic review.MethodsWe searched databases, including PubMed, SID, Magiran, Google Scholar, and Iranmedex using the following keywords in Persian and English: disorders, vision, amblyopia, refractive errors, astigmatism, student, and Iran with all the possible combinations, important, chief, and sensitive words. Search resulted in 28 articles, conducted during a period from 1996 to 2014 in Iran and their data was analyzed using meta-analysis and random effects model. Heterogeneity of studies was assessed using I2 index, and data was finally analyzed with R Software and STATA (Version 11.2).ResultsTotal number of subjects in the study was 1,117,274, aged 2 to 18 years. The prevalence of disorders related to amblyopia, refractive error, and strabismus was 8%, 7% and 1%, respectively. The greatest amount of refractive error was related to astigmatism (19%) followed by myopia (17%).ConclusionAccording to the study results, the prevalence of visual disorders among Iranian students indicated the critical necessity of screening programs for prevention of visual disorders in this age group.

Visual Disorders Prevalence in Primary School Children in Kermanshah (2001)

Introduction: Screening visual disorder in children is very important, since early diagnosing preventable factors can help visual health of children. This study was carried out to determine prevalence of visual defects in primary school children in Kermanshah during 2001. Materials & Methods: 4533 primary school children were studied in this cluster and randomised sampling cross sectional study. Visual acuity of subjects was studied using Snellen chart. Ophthalmologist examined subjects who had visual acuity with lower than or equal to 20/40. Results: Prevalence of uncorrected defects corrected with glasses and corrected visual impairment equal to or less than 20/40 at least in one eye was 5.7%, 2.6% and 0.3% respectively. Refractive errors were the common cause of visual impairment in 87.3% of subjects.The results also showed 5.8% amblyopia, 2.3% other causes and 4.6% unexplained cause. Conclusion: Comparing the prevalence of visual disorders of the studied subjects was lower than or equal to the previous studies. The most important reasons for this reduction may be preschool screening, sampling method or genetic factors. The Common cause of visual impairment was related to correctable causes, which are curable by on time diagnosing and recommending glasses.rening sons for this claim are pwere evaluated by ophthalmologist completly.

Consanguinity and Ocular Genetic Diseases in South India: Analysis of a Five-Year Study

Objective: Consanguineous marriage is a widely practised social custom in Asia and northern Africa. In south India, Dravidian Hindus have contracted consanguineous marriages for over 2,000 years. In the present study, the influence of consanguinity on the prevalence of visual disorders was examined in patients attending a specialist genetic eye clinic. Subjects and Methods: A total of 2,335 patients attending Sankara Nethralaya, Chennai, India, were screened for genetic eye disorders over a five-year period. The patients were drawn from all parts of India and from neighbouring countries in south Asia. Results and Discussion: Six hundred and seventy-three (28.8%) of the patients tested for ophthalmic genetic disorders reported a family history of consanguinity. The majority (n = 574) of these families were from south India. In the patient group as a whole, the most common form of consanguineous union was between first cousins (n = 367), followed by uncle/niece marriage (n = 177), equivalent to a mean coefficient of inbreeding α = 0.0202. Among the consanguineous families, 430 of 673 (63.9%) had retinitis pigmentosa, 167 of these cases were autosomal recessive and 199 were isolated cases. The public in regions such as south India should be made aware of the merits and demerits of consanguineous marriages.

Prevalence of visual disorders in Chinese schoolchildren.

We performed a vision screening of 1883 Chinese schoolchildren from 4 schools around Kuala Lumpur in June 1990. The group contained 1083-males and 800 females. Visual acuity, refractive error, oculomotor balance, and axial length were measured. The prevalence of myopia in Chinese schoolchildren was found to be 37% in the 6- to 12-year age group and 50% in the 13- to 18-year age group. Approximately 63% of the sample had unaided visual acuity of 6/6 or better and 24% had unaided acuity of 6/12 or worse. Six hundred twenty-five students (33%) failed the vision screening test and were referred for further examinations. The group which failed the vision screening test and had the highest rate of referral (46%) was the 11- to 12-year-old age group. The most common visual disorder was uncorrected myopia, accounting for 38% of the referrals (235 students). Only 26% of the sample were wearing a spectacle correction.

The Problems of Screening Children's Vision

It is widely agreed that screening of vision at schools is desirable since the prevalence of visual disorders among children is high and in a good proportion of instances adequate care would not be sought unless the disorder is uncovered by a screening programme. There is less agreement on what methods are most appropriate for school vision screening bearing in mind the need for the screening method to be efficient, easy to administer and inexpensive. The Orinda Study showed that the modified clinical technique (MCT) was efficient and not unduly expensive and that screening instruments had very high under- and over-referral rates. The present study evaluated the Mavis vision screener, an instrument which has a number of features that are appropriate to the screening of children's vision. Despite careful training of the teacher operators who were highly motivated and very conscientious, the instrument had a high over-referral rate most likely due to proximal accommodation. Although the MCT to which the instrument was compared was not infallible, it seems that this is the preferable method of school screening especially for younger children. Since myopia is the principal visual disorder to emerge during the school years, screening with the Snellen chart by lay persons in the later years at school may be an acceptable procedure provided optometrists or ophthalmologists are used for a thorough vision screening of kindergarten and year one children.

Health Problems of 14–16-Year-Old Schoolchildren: A Follow-up of Previous Health and Behavioural Assessments

Health and behavioural assessments of 352 children, previously examined at 10–12 years of age, were followed up at 14–16 years of age within the School Health Services. The health problems of the 14–16-year-olds were more serious than those of the younger children, with the onset of chronic illnesses such as terminal ileitis and diabetes. The prevalence of visual disorders increased, mainly with the development of myopia in 15.6% of all children. The functional importance of allergic disorders diminished with age. Twelve percent of the children had pronounced educational and/or adjustment problems and were discussed at the pupil personnel conference. 6.5% were given remedial education and 2.8% were partially exempted from school. There was a predominance of boys and working class children among the ‘pupil act' children. One-third of them were also registered at the Social Welfare Board because of social problems in the families. The behavioural assessments made of the children at 10–12 years of age predicted problems in half the cases, mainly in the teachers' assessments. The school health service is effective in detecting and taking care of physical illnesses and has the important task of supporting children with adjustment difficulties and in acting as counsellor to teachers having children with school problems.