智能视力表投影仪的可重复性及其与传统视力表的比较

目的：分析智能视力表投影仪在视力检查中的可重复性及其与传统视力表测量结果的比较。方法：系列病例研究。收集2022年1月4—22日在首都医科大学附属北京同仁医院就诊的眼部不适患者60例（120眼）。先通过智能视力表投影仪（LSJ-IVAC-6000A）对患者进行3次视力检测,并采用组内相关系数（ICC）评价3次测量结果之间的可重复性;再用传统灯箱的国家标准视力表测量1次,并分别采用ICC和Bland-Altman图表法分析智能视力表投影仪与传统视力表检测结果的一致性。结果：同一受检者右眼、左眼使用智能视力表投影仪测量3次的ICC值分别为0.830和0.868,双眼的ICC值均>0.8（P<0.001）;同一受检者右眼、左眼使用智能视力表投影仪和传统灯箱的国家标准视力表测量的ICC值分别为0.846和0.873,双眼的ICC值均>0.8（P<0.001）。右眼、左眼使用智能视力表投影仪和传统灯箱的国家标准视力表测量差值的95%一致性界限分别为-0.25~0.20和-0.24~0.17。结论：智能视力表投影仪的可重复性较好,与传统灯箱的国家标准视力表的测量结果相比一致性较强,应用于临床工作中可提高视力筛查的效率并节省人力和物力。     

ETDRS对数视力表在儿童视力检查中的可重复性分析

目的：探讨ETDRS对数视力表对儿童视力检查的可重复性及其影响的相关因素。方法：在流行病学调查的过程中，随机使用ETDRS对数视力表，为250位裸眼视力低于0．5和98位视力正常儿童进行裸眼视力重复检查。结果：两次视力测量之间差异的均数为0．004log±0．07；Kappa分析结果具有很好的一致性（k=0．71）；性别与视力检查一致性无明显相关（P=0．845）；年龄与视力检查一致性有显著相关性（P=0．019），年龄越小视力检查一致性越差；屈光不正与视力检查一致性也有显著相关性（P=0．000），近视度数在-1．00D—-5．00D之间的儿童视力检查一致性相对差．而正视眼的视力检查一致性较好。结论：结果提示ETDRS对数视力表适合儿童视力检查，建议推广使用。眼科学报2008；24：48-52．     

灯箱视力表与Freiburg电子视力表应用对比研究

目的 比较灯箱视力表与Freiburg电子视力表结果的一致性与可重复性,评价Freiburg电子视力表的临床应用价值。设计 诊断性技术评价。研究对象 空军杭州航空医学鉴定训练中心的工作人员86例,平均年龄（26.3±2.1）岁。方法 所有入选者均随机由2位固定检查者分别使用灯箱视力表和Freiburg电子视力表进行检查,两种视力表检查的顺序随机决定。所有检查均在同一房间内完成,房间内亮度小于3 lux。检查距离均为3 m。对不同视力表间与检查者间测量重复性采用配对t检验比较结果的差别并计算相关系数r值。主要指标 使用两种视力表获得的logMAR视力。结果 在检查者一,用灯箱视力表查,被检者logMAR视力为0.19±0.23,Freiburg电子视力表0.20±0.15,两者差值为-0.011±0.141,差异无统计学意义（t=-0.741, P=0.461）,但有显著相关性（r=0.808,P=0.000）。在检查者二,用灯箱视力表查,被检者logMAR视力为0.32±0.25,Freiburg电子视力表为0.20±0.15,两者差值为-0.118±0.151,差异有统计学意义（t=7.191, P=0.000）及显著相关性（r=0.810,P=0.000）。均用灯箱视力表,检查者一、二的差异有统计学意义（F=11.872,P=0.001）,两者显著相关（r=0.938,P=0.000）。而均用Freiburg电子视力表,检查者一、二的差异无统计学意义（F=0.019,P=0.890）,两者显著相关（r=0.986,P=0.000）。结论 Freiburg电子视力表受检查者因素的影响小于灯箱视力表,其在不同测量者间的可重复性优于灯箱视力表。（眼科, 2013, 22: 117-120）     

拥挤Kay图片视力表在学龄前儿童视力筛查中的应用

目的：采用拥挤Kay图片视力表检测学龄前儿童视力,并和标准对数视力表检测结果进行比较,探讨2种视力表检测结果是否具有一致性,以补充不能完成标准对数视力表检测的学龄前儿童的视力筛查。方法：前瞻性自身对照研究。于2021年1─5月随机选取济南市章丘区某幼儿园152名学龄前儿童进行全面眼科筛查,分别使用拥挤Kay图片视力表及标准对数视力表对其进行视力检测,并采用Wilcoxon检验进行2种视力差异性的比较,Spearman秩相关分析及Bland-Altman分析进行相关性及一致性分析。结果：152名儿童参与筛查,其中129名儿童屈光状态正常且能配合2种视力表检测。129名儿童中男74名,女55名,年龄为（52.3±7.0）个月;拥挤Kay图片测得LogMAR视力为0.10（0.09,0.10）,标准对数视力表视力为0.10（0.10,0.22）;2种视力检查方法有较好的相关性（r=0.436,P<0.001）,拥挤Kay视力表检测结果略高于标准视力表约0.04 LogMAR,差异有统计学意义（Z=-6.124,P<0.001）,Bland-Altman散点图显示98.4%的点均在一致性范围内;参与筛查儿童Kay图片视力检查配合度更高（χ2=18.007,P<0.001）。不同月龄拥挤Kay图片视力检测结果差异有统计学意义（H=13.791,P=0.003）,随年龄增长,视力呈递增趋势。结论：拥挤Kay图片视力表用于学龄前儿童视力检测,患儿配合程度高,其结果与标准对数视力表相比有较好的一致性,但Kay图片视力表所检查的视力结果高于标准视力表约0.04 LogMAR,在参考视力结果时应相应调整视力标准。     

对数视力表认识误区之管见

针对近年来有关视力标准的争议提出看法：①形觉视力标准的制定．应覆盖整个形觉视力范围。②Weber—Fechner法则至今仍是心理物理学领域包括视觉领域的指导理论。③发现对数视力表视标增率和黄金比率的关系：10√10≈√φ。说明对数视力表的设计无形中巧合了黄金比率规律。④分析了小数制和对数制两种视力数制的优缺点,认为应弃用小数制。     

噪声视力表在儿童视力检查中的可重复性分析

目的探讨噪声视力表对儿童视力检查的可重复性及其相关影响因素。方法在门诊首诊患儿中,随机选择无理解障碍及除屈光不正外无其他器质性眼病儿童200例,使用噪声视力表进行噪声视力重复检查。采用配对t检验进行统计学分析。结果两次视力测量之间差异的均数为O.03行,（P=0.515）;两次视力测量结果按性别分组无明显差异（P=1.0,P=0.262）;按年龄分组亦无明显差异（P=0.159,P=0.786）;按屈光不正分组,其中近视组两次视力测量结果有明显差异（P=0.010）。近视儿童视力检查一致性较差,而正视及远视儿童的视力检查一致性较好（P=0.133,P=0.083）。结论结果提示噪声视力表适合儿童视力检查,建议推广使用。     

改良液晶视力表初步应用

目的 探讨一种改良液晶视力表实际应用的可行性。方法 前瞻性对照研究。选取吉林大学第二医院眼科医护人员33例,男8例,女25例,年龄（27.4±8.5）岁,先使用灯箱视力表再使用改良液晶改装后的液晶视力表对其进行视力检测。由同一名检查者对受检者双眼进行测量。使用Wilcoxon符号秩和检验和Bland-Altman法评估2种测量方法的一致性。结果 灯箱视力表和改良液晶视力表测量的视力值分别为4.2～5.2（4.9）和4.2～5.1（4.9）,2种方法测量结果的差异无统计学意义（Z=-0.307,P＞0.05）。Bland-Altman图显示2种测量方法具有较好的一致性,其95%一致性界限为-0.168～0.162。结论 应用改良液晶视力表检查视力和灯箱视力表具有较高的一致性。对于特殊患者,改良液晶视力表或许更具优势。     

ETDRS表原理和使用方法及其与Snellen视力表的比较

早期糖尿病视网膜病变治疗研究（early treatment diabetic retinopathy study,ETDRS）视力表是在Bailey-Lovie视力表基础上发展出来专门用于临床试验的视力表,其原理较Snellen视力表科学和合理,精确度和可重复性都高于后者,检查所耗时间较后者长,其logMAR视力结果可直接用于视力统计。ETDRS视力表能通过不同测试距离（4、2、1 m）对极低视力进行量化和评分,并且不同测试距离视力值可相互转化。但1 m以下测量时理论值和实际测量值存在较大误差,为了避免夸大视力改进或丢失的情况,应谨慎对待不同测试距离的转化值。     

液晶视力表显示精度与显示屏点距的相关性分析

目的探讨液晶视力表测量精度与显示屏点距的关系。方法 采用标准对照研究方法,调查常用显示屏相关参数,与新标准对数视力表国家标准（GB11533-2011）的视标大小及允许误差进行推算、对比研究。结果 液晶视力表在亮度、幅宽、白度、照明方面完全符合（GB11533-2011）要求;在液晶显示精度方面,0.27 mm点距的显示屏可准确测试远视力≤5.0视力;0.1245 mm点距显示屏可准确测试远视力≤5.2视力;点距0.077 mm的显示屏准确测试远视力≤5.3视力。结论 选择合适点距和测试距离可使液晶视力表测试结果更精确。     

Lea Symbols视力表在42～78个月儿童视力检查中的重复测量可信度分析

目的：探讨Lea Symbols视力表在学龄前儿童视力检查中的重复测量可信度。方法：横断面研究。 2017年4-5月对泉州市泉港区实验幼儿园的250名42～78（61.9±10.3）个月的学龄前儿童进行全面 的眼科检查,使用Lea Symbols视力表重复测量右、左眼的单眼远视力,采用LogMAR记录法记录 视力值。采用Bland-Altman分析、加权Kappa检验、组内相关系数3种统计分析方法衡量2次测量之 间的重复测量可信度。结果：3种分析方法均显示Lea Symbols视力表在学龄前儿童视力检查中的重 复测量可信度较好,2次测量间视力的差值94.3%在1行以内,2次测量的视力值之间的相关性较高 （r=0.753,P<0.001）。在139名屈光正常儿童中,2次测量的视力值（LogMAR）平均相差0.014。在 139名屈光正常儿童中,视力与月龄的相关性是显著的,月龄越大视力越好（r第1次=-0.335,P<0.001; r第2次=-0.424,P<0.001）;性别对可重复性没有影响（P=0.197）。结论：Lea Symbols视力表可用于 中国42个月及以上学龄前儿童的视力检查,可以在临床视力检查中推广使用。     

A new Gujarati language logMAR visual acuity chart: Development and validation

Aims:

Gujarati is the main spoken language of a large proportion of the population of India. The aim of this study was to develop and validate a new Minimum Angle of Resolution (logMAR) visual acuity chart in the Gujarati language.

Materials and Methods:

A new Gujarati visual acuity chart was designed to logMAR specifications using Gujarati optotypes experimentally selected to have similar relative letter legibility under spherical and cylindrical defocus. The chart validation study was carried out using 153 adult subjects in a large clinical setting in India. Subjects who were literate in English and Gujarati participated in the study. Visual acuity was measured with the new Gujarati logMAR chart and a modified Early Treatment of Diabetic Retinopathy Study-(m-ETDRS) logMAR chart. The method of presentation was randomized between the charts. Repeat visual acuity was measured on a subsequent day with a second version of the Gujarati logMAR chart.

Results:

The Gujarati chart correlated highly with the m-ETDRS logMAR chart (r² = 0.974). The mean visual acuity difference (Gujarati – m-ETDRS logMAR) was equal to three letters (–0.06 logMAR). The Gujarati logMAR chart also proved to be highly repeatable (r² = 0.994, test-retest) with 95% CI of ± 0.04 logMAR.

Conclusions:

The new Gujarati logMAR visual acuity chart provides a valid and repeatable tool for the measurement of visual acuity in native Gujarati language speakers.     

A comparison of visual acuity measured by ETDRS chart and Standard Logarithmic Visual Acuity chart among outpatients

AIM:To compare the results of visual acuity(VA)measured by Early Treatment Diabetic Retinopathy Study(ETDRS)chart,5 m Standard Logarithm Visual Acuity(5 SL)chart,and 2.5 m Standard Logarithm Visual Acuity(2.5 SL)chart in outpatients of age 12-80 y.METHODS:Each patient(totally 2000 outpatients)had both eyes tested with ETDRS chart at 4 m,5 SL chart at 5 m,and 2.5 SL chart at 2.5 m in random order.The VA values of outpatients were categorized by ages.VA values were expressed by log MAR recording method.RESULTS:The mean VA results of ETDRS charts,5 SL,and 2.5 SL chart were 0.52±0.28,0.50±0.30,and 0.46±0.28 log MAR,respectively.There was a statistically significant difference in the three eye charts in the whole group(P<0.001).For all subjects,the correlation of VA tested with three charts was statistically significant(Spearman correlation coefficient=0.944,0.937,0.946,all P<0.001).Bland–Altman analysis shows the 95%limits of agreement between the 5 SL and 2.5 SL chart were-0.182 to 0.210,-0.139 to 0.251,and-0.151 to 0.235 log MAR,respectively.CONCLUSION:The agreement between the three eye charts is not high.The VA measured by 5 SL chart is slightly better than that by ETDRS chart and 5 SL chart would be a suitable alternative when ETDRS chart are not available in the clinical situation.The VA measured by 2.5 SL chart is about 0.5 line better than VA tested with ETDRS chart,which may overestimate VA.     

视力表照明现状调查及分析

通过对山东省泰安市各级医院及眼镜营销单位视力表照度的调查，了解视力表照明的现状，使用照度仪在视力表的八个方位测量。计算平均照度及均匀度。结果表明视力表照度不统一，同一视力表照度不均匀的现象普遍存在，这一现象应引起眼科界及视力表生产厂家的重视 。     

The development of a "reduced logMAR" visual acuity chart for use in routine clinical practice

BACKGROUND/AIMS: The advantages of logMAR acuity data over the Snellen fraction are well known, and yet existing logMAR charts have not been adopted into routine ophthalmic clinical use. As this may be due in part to the time required for a logMAR measurement, this study was performed to determine whether an abbreviated logMAR chart design could combine the advantages of existing charts with a clinically acceptable measurement time. METHODS: The test-retest variability, agreement (with the gold standard), and time taken for "single letter" (interpolated) acuity measurements taken using three prototype "reduced logMAR" (RLM) charts and the Snellen chart were compared with those of the ETDRS chart which acted as the gold standard. The Snellen chart was also scored with the more familiar "line assignment" method. The subjects undergoing these measurements were drawn from a typical clinical outpatient population exhibiting a range of acuities. RESULTS: The RLM A prototype chart achieved a test-retest variability of +/-0.24 logMAR compared with +/-0.18 for the ETDRS chart. Test-retest variability for the Snellen chart was +/-0.24 logMAR using clinically prohibitive "single letter" scoring increasing to +/-0.33 with the more usual "line assignment" method. All charts produced acuity data which agreed well with those of the ETDRS chart. "Single letter" acuity measurements using the prototype RLM charts were completed in approximately half the time of those taken using the ETDRS and Snellen charts. The duration of a Snellen "line assignment" measurement was not evaluated. CONCLUSION: The RLM A chart offers an acceptable level of test-retest variability when compared with the gold standard ETDRS chart, while reducing the measurement time by half. Also, by allowing a faster, less variable acuity measurement than the Snellen chart, the RLM A chart can bring the benefits of logMAR acuity to routine clinical practice.     

Construction and validation of a Tamil logMAR chart

Purpose:  To design, construct and validate a new Tamil logMAR visual acuity chart based on current recommendations.
Methods:  Ten Tamil letters of equal legibility were identified experimentally and were used in the chart. Two charts, one internally illuminated and one externally illuminated, were constructed for testing at 4 m distance. The repeatability of the two charts was tested. For validation, the two charts were compared with a standard English logMAR chart (ETDRS).
Results:  When compared to the ETDRS chart, a difference of 0.06 ± 0.07 and 0.07 ± 0.07 logMAR was found for the internally and externally illuminated charts respectively. Limits of agreement between the internally illuminated Tamil logMAR chart and ETDRS chart were found to be (−0.08, 0.19), and (−0.07, 0.20) for the externally illuminated chart. The test – retest results showed a difference of 0.02 ± 0.04 and 0.02 ± 0.06 logMAR for the internally and externally illuminated charts respectively. Limits of agreement for repeated measurements for the internally illuminated Tamil logMAR chart were found to be (−0.06, 0.10), and (−0.10, 0.14) for the externally illuminated chart.
Conclusions:  The newly constructed Tamil logMAR charts have good repeatability. The difference in visual acuity scores between the newly constructed Tamil logMAR chart and the standard English logMAR chart was within acceptable limits. This new chart can be used for measuring visual acuity in the literate Tamil population.     

视力表的标准化

回顾了我国多年来视力表在设计、制作和使用中存在的问题,着重分析了目前使用最普遍的两种视力表《国际标准视力表》和《标准对数视力表》存在的问题。认为视力表视力检查是评价人眼主觉视力简便而实用的方法,它只对视觉功能做粗略的评估,简便和实用是其最大的特点。因此今后在设计和使用视力表时应考虑:①设计合理、简便实用、兼顾习惯、国际接轨、全国统一;②除有通用表外,另设计出供3岁左右儿童使用的视力表。建议国家标准局在业务主管部门(卫生部及中华医学会)协助下,组织视力表问题研究专题组,广泛征求意见与建议,提出规范统一的方案。     

Evaluating a new logMAR chart designed to improve visual acuity assessment in population-based surveys

AIMS: This study aimed to evaluate a new chart designed to improve the collection of visual acuity data in population-based surveys. The Reduced logMAR E chart (RLME) employs three letters per line, 'tumbling E' optotypes, and conforms to accepted contemporary design principles. METHODS: The performance of the chart was assessed within a population-based glaucoma survey in Thailand. Performance indices were test-retest variability (TRV) and agreement with acuity data measured using the ETDRS logMAR chart which acted as the 'gold standard'. RESULTS: The 95% confidence limits for TRV of RLME acuity data were +/-0.15 logMAR. This figure is consistent with published data on the TRV of acuities measured using five-letter-per-line logMAR charts. The mean difference between RLME and ETDRS acuity data was 0.00 logMAR (95% confidence intervals of +/-0.05 logMAR) indicating that RLME acuities agreed well with those of the ETDRS chart. The chart and its method of use was readily accepted by the local ancillary staff who required only minimal training before acuity measurement could be delegated to them. CONCLUSIONS: The study demonstrated that the RLME chart is capable of accurate and repeatable acuity measurements. Certain aspects of the design of the RLME chart may be particularly pertinent to the measurement of vision in population-based surveys.     

Repeatability of near visual acuity measurement at high and low contrast

Purpose: The aim of this study was to determine the repeatability of high‐ and low‐contrast visual acuity (VA) measurements at near. Methods: Fifty‐five normal subjects were recruited. Inclusion criteria included visual acuity of at least 0.00 logarithm of minimum angle of resolution (logMAR) on each eye at distance. One eye was selected for this study, either the one with a better acuity or randomly chosen if there was no difference between the two eyes. Near VA was measured in a random order with the PolyU high‐contrast (PolyU‐HC), the PolyU low‐contrast (PolyU‐LC), the Precision high‐contrast (P‐HC) and the Precision low‐contrast (P‐LC) charts at 400 mm. Measurements were repeated after one to two weeks. Repeatability was presented using the 95% limits of agreement between visits. Results: The between‐visit repeatability was ±0.063 logMAR for high‐contrast and ±0.141 for low‐contrast using the PolyU charts. The between‐visit repeatability was ±0.120 logMAR for high‐contrast and ±0.110 for low‐contrast using the Precision charts. Seventeen subjects had high‐contrast VA better than ‐0.10 logMAR using Precision chart, which could not be measured by PolyU chart. The mean difference between high‐ and low‐contrast VA was 0.108 from the Precision charts (median difference of 0.10 or one line). Conclusions: The Precision charts could measure high‐contrast near VA to threshold level. Practitioners should be aware of a VA difference of more than one line in repetitive measurement, at both high and low contrast. A difference in near high‐ and low‐contrast VA of more than one line may warrant further investigation.