Review of guidelines for children's vision screenings

The aim of children's vision screenings is to detect visual problems that are common in this age category through valid and reliable tests. Nevertheless, the cost effectiveness of paediatric vision screenings, the nature of the tests included in the screening batteries and the ideal screening age has been the cause of much debate in Australia and worldwide. Therefore, the purpose of this review is to report on the current practice of children's vision screenings in Australia and other countries, as well as to evaluate the evidence for and against the provision of such screenings. This was undertaken through a detailed investigation of peer‐reviewed publications on this topic. The current review demonstrates that there is no agreed vision screening protocol for children in Australia. This appears to be a result of the lack of strong evidence supporting the benefit of such screenings. While amblyopia, strabismus and, to a lesser extent refractive error, are targeted by many screening programs during pre‐school and at school entry, there is less agreement regarding the value of screening for other visual conditions, such as binocular vision disorders, ocular health problems and refractive errors that are less likely to reduce distance visual acuity. In addition, in Australia, little agreement exists in the frequency and coverage of screening programs between states and territories and the screening programs that are offered are ad hoc and poorly documented. Australian children stand to benefit from improved cohesion and communication between jurisdictions and health professionals to enable an equitable provision of validated vision screening services that have the best chance of early detection and intervention for a range of paediatric visual problems.     

Random dot stereogram E in vision screening of children

The random dot stereogram E (RDE) has been shown to be a simple and effective test for the detection of binocular abnormalities and defective visual acuity in children. We determined the validity of the RDE as a screening test for reduced visual acuity, amblyopia and strabismus in two separate populations of children.
A nonselective group of 100 school children (aged 5 to 15 years) who presented consecutively to the ophthalmology department at Auckland Public Hospital were tested with the RDE. All cases of amblyopia and strabismus were detected by the RDE. Similar screening with the RDE test of 168 preschool children (aged three to four years) in the community resulted in an unacceptably high over-referral rate. The test was unreliable in the preschool age group because of difficulty in distinguishing between test failure and non-cooperation with the test. The low positive predictive value of the test in the younger age group suggests the test to be unsuitable for preschool vision screening.     

学龄前儿童弱视的早期筛查

弱视是一种由视觉敏感期异常视觉经验引起的以神经系统发育异常为主、无眼部器质性病变的疾病。视力检查是儿童弱视筛查与诊断中的重要组成部分,但对于不能言语表达的低龄儿童,视力检查受到限制。而屈光不正和屈光参差是引起弱视的最常见危险因素,近年来,对弱视的早期筛查不断延伸至对弱视相关危险因素的早期筛查,针对屈光状态的筛查方法与技术也在不断更新发展。本文试对视力检查方法和屈光性质筛查方法进行综述。     

The measurement of visual acuity in children: an evidence‐based update

Over the past decade, a number of large clinical trials have provided important information relating to the reliability and repeatability of commonly used paediatric tests of vision and their role in the diagnosis and management of paediatric ocular diseases. The aim of this review is to summarise recent findings on the use of paediatric visual acuity tests in clinical practice and to discuss the validity and accuracy of visual acuity measurements in infants and young children. We provide a broad overview of the benefits and challenges of measuring visual acuity in children and then discuss age‐appropriate tests for measuring visual acuity in infants through to school‐age children. We also discuss normative values for visual acuity in each age group and, where possible, provide comparisons of results between tests with a particular focus on the importance of optotype design.     

Final Visual Outcomes and Treatment Received for Children Referred from a UK Primary School Visual Screening Program: A Comparison of An Orthoptic-led Program with Orthoptic-delivered Services

There is little published evidence relating to the final visual acuity of children who are identified as having reduced vision at a school screening program. The school vision screening program in Leeds (led by an orthoptist but delivered by health care support workers within the school nursing team) is examined.

Results: 7807 children were screened in school between November 1, 2013, and September 1, 2014. Of these, 319 (4%) failed the screen and were referred to the general optometry service and 547 (7%) were referred to the Children’s Community Eye Service (CCES). Of the children who were referred to the CCES, 79.4% attended their first appointment and 86.4% were positive referrals. Of the children with reduced vision, 31 (8.3%) were found to have a manifest strabismus or eye movement disorder; 75 (20% of the positive referrals) required occlusion therapy for amblyopia; 52.6% of those with initially reduced vision obtained good visual acuity following spectacle correction alone within an 18- to 24-week refractive adaptation period. Of those who completed their treatment, 92.9% had vision within normal limits for their age in both eyes at discharge. Of children referred from vision screening who were found to have a defect, 64.6% had that treatment completed within three visits.

Conclusion: Vision screening identifies individuals with treatable vision defects who have a greater than 90% chance of achieving normal visual acuity with good compliance to treatment. Vision screening programs led by an orthoptist but delivered by well-trained and monitored screeners can be of as good quality as a screening program delivered by orthoptists.     

Paediatric Vision and Optometry

ABSTRACT Until recent times remarkably little attention has been paid to the visual problems of children. Few children seek professional eye care, and vision screening services provided by the school health authorities have been shown to be inadequate. National Children's Vision Week (NCVW) in 1979 was the first stage of an AOA programme to inform the public, particularly teachers, of optometrists' unique role in paediatric eye care and the importance of early intervention. The paper presents information resulting from optometry's participation in NCVW, and suggests strongly that all optometrists should be informed as to their responsibilities in paediatric eye care.     

视力检查在眼病筛查中的作用

视力检查是许多致盲性眼病基层筛查工作的第一步。目前我国儿童人群视力损伤的初步筛查主要由教育机构中的保健老师完成,一直沿用的是以裸眼远视力检查结果为基础的视力不良标准。但该标准并不符合儿童视力发育规律,且可能导致大量已接受正确屈光矫正的患儿重复筛查、诊断和治疗,不符合筛查试验的基本原理。在成年人群基层眼病筛查工作中仍存在只检查裸眼视力的状况。建议对学龄前儿童的视力筛查界值参考我国新的弱视诊断标准而制订;综合裸眼、日常和矫正视力指标来全面了解儿童视力情况;加速儿童保健专业、小儿眼科和视光学专业在儿童视力检查工作上的并轨。在成年人群中,推行日常生活视力指标进行成年人群视力损伤的筛查,并根据所筛查的特定眼病来确定视力检查的具体方案。     

An analysis of vision screening data from New York City public schools

ObjectiveThis study compares different vision screening batteries and documents the failure rates of different vision tests in children who receive periodic vision screenings.MethodsVision screenings were conducted on 1,992 preschool through fifth grade children attending schools in lower socioeconomic areas in New York City. The screening battery incorporated visual acuity, retinoscopy, cover test, stereopsis, near point of convergence, ocular motility, accommodation, color vision, and ocular health.ResultsSlightly less than one third (30%) of the children screened failed the State University of New York (SUNY) battery and were referred for a comprehensive examination, of which 249 (41%) children actually passed distance visual acuities. The referral rate for distance visual acuity alone was 19%. The referral rate for the Modified Clinical Technique (MCT) was 22%. A greater percentage (33%) of the children in grades kindergarten through fifth were referred compared with the preschoolers (20%). Only a small percentage (8%) of the children wore corrective lenses at the time of testing. There was a significant increase in the prevalence of binocular vision problems found in children from grades kindergarten through 5.ConclusionsPoor visual acuity and binocular vision problems exist in schoolchildren despite ongoing vision screenings. The results provide evidence for the necessity of periodic rescreening starting in kindergarten and the importance of screening for hyperopia and binocular vision problems in addition to distance visual acuities.     

Vision screening of older people

A recent systematic review found that between 20% and 50% of older people in the UK have undetected reduced vision and in most cases this is caused by refractive error or cataracts, and is correctable. Two approaches to improve the detection of these problems are to better publicise optometric services and to carry out community‐based vision screening of older people. Screening programmes should pass the Wilson criteria and a consideration of these highlights three inter‐related questions: ‘Is vision screening effective at detecting correctable low vision in older people?’; ‘Which tests should be included?’ and ‘Which venues are most appropriate?’ We carried out a systematic review to investigate these questions. For the first question, only one study was found which met our selection criteria. The ‘gold standard’ eye examination in this study lacked several important components, and the vision screening method that was used was not found to be very effective. The review revealed other studies, which, although not meeting our selection criteria, included relevant information. The screening studies highlight the lack of agreement on the content of a gold standard eye examination and of the test(s) that should be used to screen vision. Visual function in older people is not adequately described by high contrast visual acuity (VA), nor by self‐reports of visual difficulties. Other tests that may be relevant include visual field testing, low contrast VA, contrast sensitivity and stereo‐acuity. The pinhole test has often been used in attempts to detect uncorrected refractive errors, but results from this test can be problematic and possible reasons for this are discussed. Appropriate venues for vision screening are contingent upon the format of the vision screening programme. There is still uncertainty over the battery of vision tests that are most appropriate. This, and optimum venues for screening, require further research before it can be fully determined whether vision screening of older people meets the Wilson criteria. If a vision screening programme using a battery of vision tests, perhaps computerised, can be established, then this should be tested to determine the sensitivity and specificity for detecting the target conditions. Ultimately, longitudinal studies are necessary to determine whether such a screening programme will lead to improved visual performance and quality of life in older people.     

智障儿童眼部筛查结果与分析

目的 通过对温州地区特殊学校就读的智障儿童进行眼部健康筛查,了解智障儿童的眼部健康问题,分析相关因素,以提供相应的视觉矫正和治疗措施,及探索如何为智障儿童的眼部健康提供有效的服务.方法 调查研究.对在温州地区特殊学校就读的342名智障儿童进行眼部健康筛查,内容包括：一般信息、视力检查、眼位检查、色觉检查、眼前段检查、内眼检查以及屈光不正检查.采用Excel软件对数据进行整理、归纳和求百分比.并针对存在的视觉问题作出相应的分析和医学处理.结果 筛查患儿智力残疾为轻度至中度,心理与情绪等适应能力轻度或中度障碍,能参与部分社区活动.眼科检查发现,正视眼占46.6%,屈光不正均以低度屈光不正状态为主,大部分能通过眼镜矫正达到5.0 眼位检查显示正位眼占67.2%,隐斜视占12.9% 色觉正常者占81.9%,色觉存在明显异常者占6.4% 外眼及眼前段检查未发现明显异常者占92.7% 内眼检查未发现明显异常者占81.1%.这些患儿眼部的异常主要是眼球震颤（占50.0%）和白内障（占28.3%）.结论 智障儿童的眼部问题现患率比普通儿童高,但还是以屈光不正、眼球震颤、白内障等为主,大多为可矫正和可康复的,可以通过眼镜、手术或视觉康复等提高视功能.     

Preschool vision screening: outcome of children referred to the hospital eye service.

AIMS: To assess the outcome of children referred to the hospital eye service (HES) from an orthoptist based preschool vision screening programme. METHODS: A retrospective study was conducted of children referred from screening during a 2 year period. Children were screened by community orthoptists at 3 1/2 years of age. The main outcome measures were (1) HES findings for children referred from screening, and (2) visual outcome for amblyopic children after completion of treatment. RESULTS: The attendance rate at screening was 79.3% (6794 children): 348 children (5.1% of those screened) were referred to the HES. The HES findings were refractive error (32.9%), amblyopia (29.9%), false positive referral (20.1%), strabismus (13.2%), and other ocular disorders (3.9%). The positive predictive value of screening was 79.9%. Screening detected 48 children with straight eyed amblyopia and 43 children with strabismic amblyopia. A visual acuity of 6/9 or better in the amblyopic eye was achieved by 87.2% of straight eyed amblyopes and 64.3% of strabismic amblyopes (chi 2 = 5.27, p = 0.02). Residual amblyopia of 6/24 or worse occurred in only 5.6% of amblyopic children. CONCLUSION: Most amblyopic children detected by preschool vision screening achieve a good visual outcome with treatment. While treatment earlier in the sensitive period might be expected to give improved results, it remains to be demonstrated that preschool screening results in a better outcome than screening at school entry. Preschool vision screening also detects a significant number of children without amblyopia who have reduced vision due to refractive errors. This group of children must be included in any analysis of the cost effectiveness of preschool vision screening.     

Effectiveness of vision-screening in pre-school populations with preferential-looking cards used for assessment of visual acuity

Screening the vision of pre-school populations has been suggested as a way to assure early identification of vision problems as well as early intervention, thereby enabling normal development of the visual system and learning process. In a masked investigation, 119 pre-school children enrolled in Project Headstart with a mean age of 3.51 years (range 3 to 5 years) had their vision screened using the Modified Clinical Technique (MCT). Monocular visual acuities in this population were determined using preferential-looking (PL) cards. Visual acuity assessment of young children in screening settings is at best a challenge; yet, all 119 children were able to complete monocular acuity assessments on each eye. Acuities for nonreferrals (individuals who passed the screening) were significantly better than for referrals (individuals who failed the screening) at the 0.0167 level using a two-tailed Fisher's Exact Test with the Bonferroni Method for multiple comparisons. The effectivity of the screening technique as determined by phi-coefficient remained highest (phi = +0.94) with the visual acuity referral criterion set at 6/12 (20/40) or less either eye and/or greater than or equal to a 2-octave difference between the eyes. The resultant referral rate (17.6%) was higher than that predicted by extrapolation from the Orinda Study for this age group (12.3%) but expected because of the different socioeconomic group. PL cards enabled monocular visual acuity measurement on 100% of the children tested and measurably increased the effectiveness of the screening procedure.     

Prevalence of amblyopia and other vision disorders in young Newfoundland and Labrador children

BACKGROUND: Currently, there is a lack of adequate data on pediatric eye and vision disorders in Canada, particularly in the province of Newfoundland and Labrador. In the present study, we estimate the prevalence of eye and vision disorders among young children who participated in a vision screening program in the St. John's, Newfoundland, metropolitan region. METHODS: In daycare settings, 946 children (mean age 4.2 years) were screened with the latest tests of optics and functional vision. Those with suspected vision disorders were referred to an optometrist for a complete eye examination. From the results of these examinations, prevalence rates were estimated for several categories of vision disorders. RESULTS: Overall, we estimate that 14.0% of the children possessed significant vision disorders, the most prevalent of which were hyperopia, amblyopia, and strabismus (4.8%, 4.7%, and 4.3%, respectively). Myopia and anisometropia, on the other hand, were relatively rare (1.1% and 1.4%, respectively). In general, prevalence estimates are within the range of existing estimates from other developed nations. INTERPRETATION: Although the prevalence rates reported here must be interpreted cautiously because of methodological limitations, it appears that children in the present study do not possess an abnormally high prevalence of visual dysfunction. Nevertheless, because an estimated 14.0% of children tested had treatable vision disorders, early screening is clearly warranted in Newfoundland and Labrador.     

VISION SCREENING IN INDUSTRY: OBJECTIVES AND METHODS*

Management may decide to use vision screening to assist in selection of personnel, or as a step in the provision of better vision for employees. There are difficulties in analysing the relationships between visual abilities and job, competence and management should consult vision experts when considering the matter. Before commencing a vision screening programme the job's visual task should be analysed and the importance of the various visual parameters assessed. Vision can be screened by a modified clinical technique or with instrumental screeners. A number of instrumental screeners are described here. Results from instrumental vision Screening have good reliability and fairly good validity. For jobs of high visual demand or where vision is crucially important a modified clinical technique should be used for screening.     

无锡市滨湖区0～6岁儿童通过SureSight手持验光仪视力筛查结果分析

目的:了解无锡市滨湖区0~6岁儿童视力发育状况,为制定无锡市滨湖区儿童眼保健措施提供科学依据。方法:对无锡市滨湖区3695名0~6岁学龄前儿童运用SureSight手持验光仪视力快速检测眼屈光状态,参照由美国伟伦公司提供的各年龄段屈光筛查转诊标准来确定筛查结果。并且在筛查视力的同时完成全面的眼部检查。结果:视力筛查儿童总异常率为9.76%,可疑率为5.40%,我们发现随着幼儿年龄的增长异常和可疑检出率有上升趋势,并且各年龄段视力筛查结果有差异(χ²=15.913,P=0.014),但男孩和女孩之间无差异(χ²=7.200,P=0.066)。在各个年龄组中视力异常比例最高的是散光(13.89%、17.96%、17.62%、11.50%),其次是远视(0.35%、1.91%、3.60%、8.86%)和屈光参差(0.69%、0.67%、1.64%、2.07%)。五种类型在各年龄段中分布的比例如下:远视(4.38%)、近视(0.82%)、散光(15.65%)、屈光参差(1.42%)和其他屈光问题(0.466%)。0~3岁学龄前儿童散光患病率为6.94%(95%CI:4.90%~9.00%),3~4岁为8.98%(95%CI:7.80%~10.20%),4~5岁为8.81%(95%CI:7.70%~9.90%),5~6岁为5.75%(95%CI:4.80%~6.70%)。在不同年龄组中散光患病率无差异(χ²=0.872,P=0.929)。结论:从我们的筛查结果中发现散光是学龄前儿童最常见的屈光不正类型,其次是远视和屈光参差,但我们并没有发现近视,从而证实了先前的研究,即近视并没有在早期发展。最后我们强调应定期实施学龄前儿童视力筛查,倡导社会重视学龄前儿童视力保护及眼睛的健康管理。     

Student-led screening of school children for refractive error correction

Purpose: Detection and correction of uncorrected refractive errors among 12 million children is an overwhelming task for the 500 currently available eye-care professionals in Nepal. A mid-term review of VISION 2020 goals in Nepal has recommended utilizing alternative human resources that could screen children for visual impairment. This study was conducted to assess the validity of vision screening of school children by trained high school students when compared to optometrist testing as the gold standard.

Methods: A total of 150 students were selected, based on their merit by the headmasters of 25 schools in Nepal and trained for two days by optometrists to screen visual acuity of their peers. Visual acuity ≤ 6/12 in either eye was referred as abnormal vision. A random sample of 1,209 screened students was selected and their visual acuity was reassessed by optometrists under the same settings adopted by trained students. Using optometrist scores as the gold standard, screening results of trained students were analyzed for validity.

Results: Mean age of screened students was 12.2 ± 3.03 years (range: 4–19 years) and 57.4% of them were female. Sensitivity of vision screening test done by trained students was 81.7% and the specificity was 97.6%. A positive predictive value of the test was 77.3% and negative predictive value was 98.2%.

Conclusions: With high sensitivity and specificity values, vision screening done by trained students is effective for screening visual acuity of school children. Countries with limited eye-care professionals and infrastructures can effectively train and utilize students for timely detection of poor vision among children.     

Negative predictive value of a vision screening program aimed at children aged 3 to 4 years old

PURPOSE: Nova Scotia has a vision screening program which assesses children aged 4[1\2] to 5[1\2] years. However, its use in younger children proved impossible. This study will examine a modified screening protocol for the younger children (3 to 4 years old) and determine its negative predictive value and minimum age for reliable application. MATERIALS AND METHODS: Public health nurses administered the study protocol to 3- to 4-year-old children. One hundred seventy-eight children were screened over two summers. Medical and family history, external inspection, as well as measures of visual acuity with the Lea Hyvarinen symbols chart and stereoacuity with Frisby plates were recorded. Results were compared with a gold standard examination that included full orthoptic and ophthalmologic evaluations. One hundred forty-one (79%) children underwent the gold standard examination. Agreement between screening and gold standard examinations was studied. RESULTS: Data showed increased concordance between screening and gold standard examination results with increasing age up to 41 months. Negative predictive value (NPV) and specificity also improved when data were separated by this age. In children <41 months old, the screening test NPV was 90%, specificity, 68%, and sensitivity, 75%. In comparison, children >/=41 months old had screening test NPV of 96%, specificity, 95%, and sensitivity, 50%. Specificity was higher in the older age group ( P < 0.001). Sensitivity was lower ( P = 0.004). CONCLUSION: This study's vision screening protocol appears better suited for children 41 months and older. They had better pass/fail reproducibility than children <41 months. The test's simplicity allows easy use by non-eye-care professionals. It could potentially lower the reliable screening age of children by 13 months, from 54 months of age (4[1\2] years old) to 41 months. This screening may miss some refractive errors and microtropia/monofixation syndrome, despite normal visual acuity, stereoacuity, and external inspection.     

上海市学龄前儿童视力现况分析

目的了解学龄前儿童视力现况,为儿童眼保健计划提供依据。方法选择上海市具有代表性的三个区部分学龄前儿童（〉3～6岁）进行常规远视力检查,对视力结果按眼别、性别、年龄等进行统计与分析。结果〉3-4岁、-5岁、-6岁视力低常率分别为90．46％、66．99％和36．75％。女性高于男性。以人数计高于以眼数计。不同眼别结果差异无显著性。不同地区视力低常率有显著性差异。视力低常者中,轻度低常占95．57％。结论学龄前儿童远视力普查是儿童眼保健的重要指标,结果受多种因素影响,必须正确分析检查结果。     

甘肃省兰州市城关区学龄前儿童视力与屈光状态调查

目的对兰州市城关区学龄前儿童的视力及其屈光状态进行调查,以发现超出生理范围的视力异常及屈光异常。方法横断面调查研究。采用整群抽样的方法对兰州市城关区10所幼儿园的2 841例3～6岁学龄前儿童进行裸眼远视力及Suresight屈光筛查仪检查,实际受检2 754例（5 508眼）,计量资料采用t检验或方差分析,分类资料采用卡方检验或线性趋势检验。结果兰州市城关区学龄前儿童视力异常检出率为13.9%,不同年龄组间视力异常检出率存在差异（?字２=31.80,P＜0.05）,且随着年龄增长视力异常检出率呈下降趋势（?字２lineartrend=31.59,P＜0.05）。屈光异常占检查总人数的13.13%,随着年龄增加,复性远视散光人数和单纯远视人数均逐渐减少（?字２lineartrend,复性远视散光=16.01,P＜0.05;?字２lineartrend,单纯远视=9.11,P＜0.05）。结论兰州市城关区3～6岁的学龄前儿童视力异常随着年龄增长呈下降趋势,提示视力随年龄增加逐步升高;屈光异常以单纯远视为主,远视屈光度向远视减小方向发展,符合儿童视力及眼屈光发育的规律。     

加强原发性青光眼的机会性筛查工作

早期发现和确诊原发性青光眼患者有利于减少青光眼引起的盲和视力损伤.开展机会性筛查工作是更早、更及时地发现原发性青光眼患者的有效方法.机会性筛查是指一些人因为健康体检或者其他问题来眼科就诊时,眼科医师有意识地进行青光眼方面的必要检查而发现的有关青光眼的情况,这应当是眼科临床工作的一部分.由于原发性闭角型青光眼与原发性开角型青光眼是两种不同类型的青光眼,具有明显不同的发病机制和临床特征,因此所采用的机会性筛查方法应当不同.作为眼科医师应当明确认识原发性闭角型青光眼和原发性开角型青光眼的发生和发展是一个连续体的概念,注意筛查试验和诊断试验的重要区别,选择筛查试验方法要力求简便、易行,重视防治青光眼人力资源的开发和应用,这对于做好机会性筛查工作十分重要.