Research progress on commonly used visual acuity charts for preschool children / 国际眼科杂志(Guoji Yanke Zazhi)

Preschool age(3-6 years old)is a critical period for visual development, and it is crucial to detect and treat visual problems in preschool children as early as possible. Visual acuity charts are important tools for screening visual issues in children. In China, the commonly used charts are the standard logarithmic visual acuity chart and the pediatric optotype chart, while overseas, the Lea, HOTV, and ETDRS visual acuity charts are frequently employed. Numerous studies have reported the measurability, repeatability, and sensitivity of these three charts in diagnosing visual-related problems in children. However, the application of these three charts is relatively limited in China. This article provides a comprehensive review of the design principles, clinical applications, and characteristics of these three visual acuity charts, so as to better understand their applicability and limitations in preschool children, and provide reference for the selection and improvement of vision examination methods in the future.

Agreement between Lea Symbols and Patti Pics visual acuity in children and adults

Background Patti Pics (PP) and Lea Symbols (LS) are commonly used by eye care practitioners worldwide. Although the relationship between the two tests is fairly well understood, the availability of different chart designs (single optotypes, multiple optotypes, multiple optotypes with crowding box) merits futher understanding. The purpose of this study is to explore the agreement between the acuity measures obtained with Patti Pics and Lea Symbols in children and adults and compare their performance with the Sloan Letter (SL) chart in adults. Methods Monocular visual acuity was obtained from ninety-three 3 to 5-year-old children using Patti Pics and Lea Symbols. Acuities were also obtained from 113 adults using the same tests under identical conditions. Acuity results obtained with the pediatric tests were compared with the gold-standard Sloan Letter chart in adults. The Bland-Altman method was implemented to compare the level of agreement between tests. Results Patti Pics yielded worse visual acuity than the Lea Symbols by approximately half a logMAR line in both children (mean difference: -0.07 ± 0.07 logMAR, p <0.01) and adults (Mean difference: -0.05 ± 0.06 logMAR, p <0.01). The 95% limits of agreement between Lea Symbol acuity and Patti pics acuity in children was ± 0.14 logMAR. Mean difference between the Sloan Letter chart and Lea Symbols acuity was not statistically significant (p = 0.08) in adults but the difference was statistically significant between PP and SL (p<0.001). The 95% limits of agreement between LS and SL and between PP and SL was ± 0.19 logMAR and ± 0.22 logMAR, respectively. Conclusion Patti Pics consistently underestimated visual acuity as compared to Lea Symbols both in children and adults although the differences were not clinically significant. The LS and PP did not yield clinically significant differences in acuities when compared with Sloan letters in adults. (AU)

Agreement between Lea Symbols and Patti Pics visual acuity in children and adults.

BACKGROUND: Patti Pics (PP) and Lea Symbols (LS) are commonly used by eye care practitioners worldwide. Although the relationship between the two tests is fairly well understood, the availability of different chart designs (single optotypes, multiple optotypes, multiple optotypes with crowding box) merits futher understanding. The purpose of this study is to explore the agreement between the acuity measures obtained with Patti Pics and Lea Symbols in children and adults and compare their performance with the Sloan Letter (SL) chart in adults. METHODS: Monocular visual acuity was obtained from ninety-three 3 to 5-year-old children using Patti Pics and Lea Symbols. Acuities were also obtained from 113 adults using the same tests under identical conditions. Acuity results obtained with the pediatric tests were compared with the gold-standard Sloan Letter chart in adults. The Bland-Altman method was implemented to compare the level of agreement between tests. RESULTS: Patti Pics yielded worse visual acuity than the Lea Symbols by approximately half a logMAR line in both children (mean difference: -0.07 ± 0.07 logMAR, p <0.01) and adults (Mean difference: -0.05 ± 0.06 logMAR, p <0.01). The 95% limits of agreement between Lea Symbol acuity and Patti pics acuity in children was ± 0.14 logMAR. Mean difference between the Sloan Letter chart and Lea Symbols acuity was not statistically significant (p = 0.08) in adults but the difference was statistically significant between PP and SL (p<0.001). The 95% limits of agreement between LS and SL and between PP and SL was ± 0.19 logMAR and ± 0.22 logMAR, respectively. CONCLUSION: Patti Pics consistently underestimated visual acuity as compared to Lea Symbols both in children and adults although the differences were not clinically significant. The LS and PP did not yield clinically significant differences in acuities when compared with Sloan letters in adults.

Is LEA symbol better compared to Snellen chart for visual acuity assessment in preschool children?

Aim: To compare visual acuity using the LEA symbol chart with Snellen E test chart in preschool children of age 3-5 years. Patients and methods: Inclusion criteria: 50 emmetropic children aged 3 to 5 years. Exclusion criteria: Strabismus, amblyopia, ametropia, and any organic eye disease. A pseudo randomized protocol was used to test visual acuity (VA) in each subject monocularly on both eyes using Snellen E chart and LEA symbol chart. Visual acuity for both charts was scored as smallest optotype size which the child correctly identified 3 of maximum 4 optotypes. The strength of agreement on VA between two charts was tested using Interclass correlation coefficient (ICC). A Mann-Whitney U test was applied to compare both the groups. Results: Boys: Girls = 26:24 with a mean age and standard deviation of 4.12 + 0.79 years. ICC between Snellen's and LEA symbol chart was 0.256 and 0.213 for right and left eye respectively. Analysis of the two samples using Mann-Whitney test showed a significant difference between the two charts (p value <0.000). Conclusion: LEA symbol test showed only a fair agreement with Snellen E charts for visual acuity measurements. Visual acuity measurement with LEA symbol chart showed significantly higher scores as compared to Snellen's chart.

Comparative analysis of Lea Symbols chart and ETDRS chart in Chinese preschool children's vision examination / 中华实验眼科杂志

Objective@#To compare cooperation degree and visual acuity difference between Lea Symbols chart and ETDRS chart in Chinese preschool children.@*Methods@#A prospective self-control study design was performed.Two hundred and forty-one children aged from 42 months to 78 months in Quanzhou Quangang Experimental Kindergarten were enrolled and the mean age was (61.9±10.3) months.Among them, 132 pre-school children had normal refractive index.All children completed comprehensive ophthalmological examinations and measurement of monocular visual acuity using Lea Symbols chart and ETDRS chart.All monocular visual acuity scores were recorded in LogMAR form.This study followed the Declaration of Helsinki and this study protocol was approved by Medical Ethics Committee of The Second Affiliated Hospital of Fujian Medical University (No.2017[62]). Written informed consent was obtained from all guardians before entering the study.@*Results@#The cooperation degrees of Lea Symbols chart and ETDRS chart were 96.7% and 95.0% in 42-78 months of children, respectively, with no significant difference between the two visual acuity tables (χ2=1.669, P>0.05). The visual acuity measured by Lea Symbols chart was positively correlated with that measured by ETDRS chart (rs=0.726, P<0.001). The measurement consistency of the two chart was good (Kappa=0.531). Among 132 normal refractive children, the visual acuity level measured by Lea Symbols chart was higher than that measured by ETDRS chart (W=-7.461, P<0.001); the measurement consistency of the two visual acuity chart was good (Kappa=0.467). There was no significant difference between the two charts in measuring the binocular vision difference (W=-0.889, P=0.374); the visual acuity levels of boys measured by Lea Symbols chart and ETDRS chart were higher than those of girls, and the difference was statistically significant (U=-3.352, -4.679; both at P<0.001); the visual acuity values measured by Lea Symbols chart and ETDRS chart were negatively correlated with age (rs=-0.423, -0.437; both at P<0.001); the visual acuity measured by Lea Symbols chart was higher than that measured by ETDRS chart in different age groups, and the differences were statistically significant (all at P<0.001).@*Conclusions@#The measurement of visual acuity by Lea Symbols chart and ETDRS chart can be achieved with a high cooperation degree in 42 months and older children.The visual acuity measured by Lea Symbols chart is higher than that measured by ETDRS chart.In the preschool children's vision screening, we should pay attention to the difference between the two kinds of visual charts, and be careful to judge the abnormal vision.

Comparative analysis of Lea Symbols chart and ETDRS chart in Chinese preschool children ' s vision examination / 中华实验眼科杂志

Objective To compare cooperation degree and visual acuity difference between Lea Symbols chart and ETDRS chart in Chinese preschool children. Methods A prospective self-control study design was performed. Two hundred and forty-one children aged from 42 months to 78 months in Quanzhou Quangang Experimental Kindergarten were enrolled and the mean age was (61. 9±10. 3) months. Among them,132 pre-school children had normal refractive index. All children completed comprehensive ophthalmological examinations and measurement of monocular visual acuity using Lea Symbols chart and ETDRS chart. All monocular visual acuity scores were recorded in LogMAR form. This study followed the Declaration of Helsinki and this study protocol was approved by Medical Ethics Committee of The Second Affiliated Hospital of Fujian Medical University ( No. 2017 [ 62 ] ) . Written informed consent was obtained from all guardians before entering the study. Results The cooperation degrees of Lea Symbols chart and ETDRS chart were 96. 7％ and 95. 0％ in 42-78 months of children,respectively, with no significant difference between the two visual acuity tables (χ2=1. 669,P>0. 05). The visual acuity measured by Lea Symbols chart was positively correlated with that measured by ETDRS chart (rs=0. 726,P<0. 001). The measurement consistency of the two chart was good ( Kappa=0. 531 ) . Among 132 normal refractive children, the visual acuity level measured by Lea Symbols chart was higher than that measured by ETDRS chart (W=-7. 461,P<0. 001);the measurement consistency of the two visual acuity chart was good (Kappa=0. 467). There was no significant difference between the two charts in measuring the binocular vision difference (W=-0. 889,P=0. 374);the visual acuity levels of boys measured by Lea Symbols chart and ETDRS chart were higher than those of girls,and the difference was statistically significant (U=-3. 352,-4. 679;both at P<0. 001);the visual acuity values measured by Lea Symbols chart and ETDRS chart were negatively correlated with age ( rs =-0. 423,-0. 437;both at P<0. 001 );the visual acuity measured by Lea Symbols chart was higher than that measured by ETDRS chart in different age groups,and the differences were statistically significant (all at P<0. 001). Conclusions The measurement of visual acuity by Lea Symbols chart and ETDRS chart can be achieved with a high cooperation degree in 42 months and older children. The visual acuity measured by Lea Symbols chart is higher than that measured by ETDRS chart. In the preschool children's vision screening,we should pay attention to the difference between the two kinds of visual charts, and be careful to judge the abnormal vision.

An Eye on Vision: 20 Questions About Vision Screening and Eye Health.

Current evidence-based and best practice vision screening and eye health approaches, tools, and procedures are the result of revised national guidelines in the past 3 years and advances in research during the last 16 years. To help the busy school nurse with little time to keep up with changes in children's vision practices and a growing body of literature, the National Center for Children's Vision and Eye Health at Prevent Blindness is providing answers to 20 questions received most often from the field. Question topics are: (1) arranging the screening environment, (2) occluders to cover the eyes during vision screening, (3) optotype-based screening at distance, (4) optotype-based screening at near, (5) instrument-based screening, (6) muscle imbalance screening, (7) referrals, and (8) vision screening certification.

Comparison of visual acuity measurements via three different methods in preschool children: Lea symbols, crowded Lea symbols, Snellen E chart.

PURPOSE: The aim of this study was to compare three different methods to measure visual acuity (VA) in healthy and amblyopic preschool children: a Snellen E chart (SE), a single Lea symbols (SLS), and a crowded Lea symbols (CLS). METHODS: Seventy-eight eyes of 54 patients (28 females, 26 males) were included in this cross-sectional, comparative study. The control group consisted of 30 healthy cases, and the amblyopic group consisted of 24 patients with amblyopia. Best-corrected VA (BCVA) measurements with SLS, CLS, and SE were compared in control eyes (CE), amblyopic eyes (AE), and fellow eyes (FE) separately. RESULTS: The mean age of the cohort was 5.7 ± 0.7 years (range 5-7 years). The mean refractive error was +1.02 ± 0.36 D (diopter, spherical equivalent) in CE, +5.59 ± 2.45 D in AE, and +3.96 ± 2.38 D in FE. The median BCVA (logMAR) was (in order of SLS, CLS, and SE) 0.00 [interquartile range (IQR) 0.10], 0.10 (IQR 0.10), 0.00 (IQR 0.10) in CE, 0.25 (IQR 0.33), 0.35 (IQR 0.30), 0.25 (IQR 0.38) in AE, and 0.10 (IQR 0.08), 0.10 (IQR 0.00), 0.10 (IQR 0.10) in FE. There was no statistically significant difference between the three methods in terms of the CE or FE (p > 0.05). In contrast, there was a statistically significant difference in AE (p < 0.05). The mean VA measurement with SLS was higher compared with CLS in AE. A positive and strong correlation between the three charts was found in all of the groups (p < 0.001). CONCLUSION: We found SLS, CLS, and SE to be consistent: all three methods can be used to obtain measurements of VA in healthy and amblyopic preschool children.

Review on visual acuity charts for preschool children / 中华实验眼科杂志

The preschool age is an important stage for the development of children's vision.Visual problems can affect visual development of children,so it is necessary for preschool children to have vision examination.As an important method of preschool vision screening,visual acuity charts can be used for early screening of eye diseases in children.The benefits of screening before school entry have been demonstrated in practice.There are many kinds of visual acuity charts that can be used to test the vision acuity of preschool children aged 3 to 6 years.This review introduced the design of visual acuity charts and lists several types of charts for screening of preschool children.Simultaneously,we have analyzed a number of papers that compared preschool vision screening methods.The vision examination on children aged 3 to 6 years was necessary to discover various visual impairments.Choosing an appropriate visual acuity chart is the focus of low vision rehabilitation research.

Effect of simulated refractive error on adult visual acuity for paediatric tests.

PURPOSE: Although vanishing optotype preferential-looking tasks are commonly used to measure visual acuity (VA), the relative sensitivity of these tests to refractive error is not well understood. To address this issue, we determined the effect of spherical and astigmatic simulated refractive errors on adult VA measures obtained using vanishing optotypes, picture optotypes and Sloan letters. METHODS: VA was determined uniocularly for adults under conditions of spherical (0.0-3.0 DS; n = 23) and astigmatic (0.0-3.0 DC at 90° and 180°; n = 20) defocus using the Cardiff Acuity Test (vanishing optotypes), crowded linear Lea Symbols (picture-optotype recognition task) and the Early Treatment of Diabetic Retinopathy Study (ETDRS) letter chart. RESULTS: The Cardiff Acuity Test over-estimated VA compared with the Lea Symbols and ETDRS charts in both focused and defocused conditions. The mean difference between the Cardiff Acuity Test and the ETDRS chart was 0.31 logMAR (95% limits of agreement (LOA) 0.10-0.52 logMAR) in focused conditions and 0.64 logMAR (95% LOA 0.25-1.05 logMAR) with 3D of spherical defocus. Defocus degraded VA on all charts, however there was a significant chart-by-defocus interaction whereby the Cardiff Acuity Test was more resistant to the effects of both spherical (P < 0.0001) and cylindrical (P < 0.001) optical defocus than the recognition acuity tasks at all defocus levels. CONCLUSION: Although the Cardiff Acuity Test provides an easy method for VA measurement in infants and toddlers, there is a considerable overestimation of VA compared with recognition acuity tasks particularly in the presence of defocus. A simple correction factor (of for example three lines overestimate) cannot be applied to Cardiff acuity measures as there is increasing over-estimation of VA with increasing defocus. Infants with significant refractive error may fall within normal visual acuity ranges for the Cardiff Acuity Test.

Comparing Visual Acuity Measured by Lea Symbols and Patti Pics.

INTRODUCTION: There is little data validating most illiterate eye charts. Lea Symbols®, however, have been well validated in numerous studies. In this study, we compare the assessment of visual acuity employing both the Lea Symbol hanging wall Early Treatment Diabetic Retinopathy Study (ETDRS)-style chart and a similar Patti Pics® ETDRS-style chart in order to determine whether the two charts provide clinically similar data. METHODS: We tested the vision of the right eyes of fifty-two consecutive patients. Patients were cooperative children or adults between the ages of 3 and 88 years (mean 58 years). We alternated the order of the chart used first. Patients were also categorized by age and by visual acuity. RESULTS: The visual acuities measured by the two charts were equal for 83% of the measurements (forty-three eyes). In 8% of eyes (four eyes), the visual acuity measured with the Lea Symbols was one line better than that measured by the Patti Pics; in 9% of eyes (five eyes), the acuity from the Patti Pics chart measured one line better than the Lea Symbols. There was no difference in measurements for either adults or children or among patients with different visual acuities. CONCLUSION: We believe this study will serve to provide useful information when choosing an eye chart to assess visual acuity in a clinic setting. Patti Pics performed similarly to Lea Symbols in adults and children tested in a multi-specialty ophthalmology practice. We suspect that it would also perform similarly in the primary care and school settings.

Vision and eye health: moving into the digital age with instrument-based vision screening.

Significant advancements in vision screening research are leading to improved design, functionality, and reliability of screening tools. Presently, two vision screening approaches are available to school nurses for children ages 3 years and older: optotype-based screening and instrument-based screening. Optotype-based screening pertains to tests of visual acuity using optotypes (e.g., pictures, letters, and numbers), which children identify to determine visual acuity. Instrument-based screening pertains to automated devices that measure amblyogenic risk factors, such as refractive error, media opacities, and eye misalignment. Differences between the two approaches; best and acceptable practice recommendations for both approaches; unacceptable tests of visual acuity; and best, acceptable, and unacceptable occluders are described.

Comparison of the Lea Symbols and HOTV charts for preschool vision screening from age 3 to 4 . 5 years old / 国际眼科杂志(Guoji Yanke Zazhi)

AlM:To evaluate the applicability and the development of the normal visual acuity from age 3 to 3. 5 years using Lea Symbols and HOTV charts. METHODS:lt was a survey research study. Totally, 133 preschoolers ( 266 eyes ) between 3 to 4. 5 years old recruited from two kid-gardens in Guangzhou were tested with both the Lea Symbols chart and the HOTV chart. Outcome measures were monocular logarithm of the minimum angle of resolution ( logMAR) visual acuity and inter-eye acuity difference in logMAR units for each test. RESULTS: The testability rates of the two charts were high (96. 24% vs 92. 48%, respectively), but difference was not statistically significant (P>0. 05). The difference between the two kind of monocular vision was not statistically significant (the right eye: t=0. 517, P=0. 606;the left eye: t = - 0. 618, P = 0. 538 ). There was no significant difference between different eye ( Lea Symbols chart:t=0. 638, P=0. 525; HOTV chart: t= -0. 897, P=0. 372). The visual acuities of the boys were better than those of the girls, but the difference was not statistically significant (P>0. 05). The results which came from visual acuities with the two charts for the corresponding age groups (3-year-old group, 3. 5-year-old group, 4-year-old group, 4. 5-year-old group) indicated that the visual acuities of the preschoolers were improving with increasing age, but the difference among the visual acuities with the Lea Symbols chart was not statistically significant (the right eye:F=2. 662, P=0. 052;the left eye:F=1. 850, P=0. 143). However the difference among the visual acuities with the HOTV chart was statistically significant (the right eye:F=4. 518, P=0. 005;the left eye:F=3. 893, P=0. 011). CONCLUSlON: Both Lea Symbols and HOTV chars are accepted and appropriate for preschool vision screening from 3 to 4. 5 years old. The monocular visual acuity of preschoolers from age 3 to 4. 5 years could be assessed was similar using the two charts. There is no correlation between visual acuity and different eye. There is no statistical difference between the genders. The results further demonstrate that the preschoolers whose age reached three years old have the ability to accept the Subjective vision checks. Also the development of the normal visual acuity is faster in the early stage.

2014 updated recommendations for preschool vision screening: Guidelines for Filipino children entering the Philippine public school system

@#In 2004, the University of the Philippines Manila published the Philippine Guidelines on Periodic Health Examination (PHEX): Effective Screening for Diseases among Apparently Healthy Filipinos. 1 The document was envisioned to “contribute… to the quality and efficiency of health care and health maintenance for all Filipinos… It was an appeal for rational medical decision-making, and an important step toward “equitable distribution of health and health resources.” The guidelines were prepared by designated task forces, with vision disorders, specifically vision impairment, and glaucoma identified as areas of interest. PHEX recommendations were drafted using standardized principles and a common protocol, with each statement undergoing four phases of development: (1) preparation of the evidence- based draft; (2) en banc meeting that gave panelists a chance to assess and revise the draft, where issues of feasibility, resource limitations, value judgment, and experts’ opinions were taken into account. A consensus was declared when at least 75% agreed on a recommendation; (3) for unresolved issues, modified Delphi technique was employed by correspondence until a consensus was reached or a maximum of three circulations were accomplished. If still unresolved, the issue was labeled as such and included in the final draft; (4) lastly, a public forum was conducted before the final draft was written. In this manner, the recommendations for Screening for Visual Impairment were written by the Task Force for Vision Disorders.

Comparison of visual acuity results in preschool children with lea symbols and Bailey-Lovie E chart.

PURPOSE: To compare visual acuity with two visual acuity charts in preschool children. MATERIALS AND METHODS: Visual acuity measurement with Lea symbols and Bailey-Lovie tumbling E chart was performed on children between 3 and 6 years of age. Visual acuity data from the two charts were analyzed with Bland-Altman plot to determine the limits of agreement. The Wilcoxon signed test was performed in children aged 3-4 years and in children aged 5-6 years separately to evaluate the influence of age. The inter-eye difference between the two charts were further analyzed with the paired t-test. A p value > 0.05 was considered statistically significant. RESULTS: A total of 47 children were enrolled for the study. The average logarithm of the Minimum Angle of Resolution (LogMAR) monocular visual acuity with Lea symbols (0.17 ± 0.13) was better than the Bailey-Lovie tumbling E chart (0.22 ± 0.14). The mean difference between Bailey-Lovie tumbling E chart and Lea symbol chart was 0.05 ± 0.12 in logMAR units. A second analysis eliminating outliers showed the same result but lower differences (n = 43, 0.05 ± 0.05 logMAR units). Visual acuity results between the two charts in children aged 3-4 years showed a significant difference (p = 0.000), but not for children aged 5-6 years (p = 0.059). Inter-eye differences between the two charts was not statistically significant (p = 0.77). CONCLUSION: Bailey-Lovie tumbling E chart is comparable to the Lea symbols chart in pre-school children. But preference should be given to Lea symbols for children aged 3-4 years as the symbols are more familiar than a directional test for this age group.