Symptoms associated with VDT use

Symptoms associated with the eyes were recorded by a group of 92 video display terminal (VDT) users over five days. A diary was maintained for the symptoms and other task related factors such as the type of work performed. Diary entries were recorded approximately every two hours. Symptoms were classified as either ocular (a range of discomfort symptoms), visual (blur or double vision) and systemic (headache or postural symptoms). Tired eyes and headaches were the most frequently reported symptoms. Comparing the symptoms reported during VDT work sessions and the clerical (non-VDT) work sessions, there was a small but consistent trend towards more frequent symptoms during VDT sessions. Almost all types of symptoms showed a significant increase in frequency over the day (time of day effect).     

A survey of symptoms and eye safety practices among welders

Welding is a task which is potentially hazardous to the eyes. In this study we have administered a questionnaire to 128 welders to investigate ocular symptoms and eye safety practices when welding. The welders demonstrated high levels of discomfort symptoms which were correlated with the length of unprotected exposure to nearby welding, the number of welding flashes received and the length of time spent welding. Dust and fumes in the workplace were also a frequent cause of ocular discomfort. Foreign body injuries were common among the welders, many of whom also reported after-images persisting following welding.     

视屏终端对视功能影响的观察

目的　探讨视屏终端(VDT)作业对青年学生视功能的影响,以揭示VDT作业的累积作用与眼保健的关系,为防治提供可能依据。方法　对5 0例长期接触VDT的青年学生,在1年内进行3次视功能系列检查,并与对照组进行比较分析。结果　观察组在观察期间出现视疲劳者逐步增加,各阶段均明显高于对照组,1年间增加例数与对照组比较差异有显著意义(P <0 . 0 5 )。视力下降和泪膜破裂时间异常等都明显高与对照组(P <0 .0 5 ) ,屈光改变例数比对照组多,但差异无显著意义(P>0 . 0 5 )。结论　VDT作业累积对视功能有一定的影响。     

Vision and the Visual Display Unit. A Review

ABSTRACT This paper presents a review of the literature concerning vision as it relates to the operation of visual display units (VDUs). The factors leading to asthenopic complaints amongst VDU operators are assessed and the risk of permanent injury discussed. Recommendations are made on the examination of the eye and vision of VDU operators.     

IMI Accommodation and Binocular Vision in Myopia Development and Progression

The role of accommodation in myopia development and progression has been debated for decades. More recently, the understanding of the mechanisms involved in accommodation and the consequent alterations in ocular parameters has expanded. This International Myopia Institute white paper reviews the variations in ocular parameters that occur with accommodation and the mechanisms involved in accommodation and myopia development and progression. Convergence is synergistically linked with accommodation and the impact of this on myopia has also been critiqued. Specific topics reviewed included accommodation and myopia, role of spatial frequency, and contrast of the task of objects in the near environment, color cues to accommodation, lag of accommodation, accommodative-convergence ratio, and near phoria status. Aspects of retinal blur from the lag of accommodation, the impact of spatial frequency at near and a short working distance may all be implicated in myopia development and progression. The response of the ciliary body and its links with changes in the choroid remain to be explored. Further research is critical to understanding the factors underlying accommodative and binocular mechanisms for myopia development and its progression and to guide recommendations for targeted interventions to slow myopia progression.     

七叶洋地黄双苷滴眼液治疗VDT综合征的有效性和临床安全性研究

目的:探讨七叶洋地黄双苷滴眼液对视屏显示终端(visual display terminal,VDT)综合征的有效性和临床安全性。方法:采用自身对照。单独应用七叶洋地黄双苷滴眼液点眼,观察用药前后VDT综合征相关症状,包括:近距离工作不能持久、眼及眼睑周围疼痛、异物感、眼睑沉重、视物模糊复视、眼红、干涩流泪、头痛、恶心呕吐、眩晕共10项。结果:患者VDT综合征明显改善,观察期间未发现局部及全身不良反应。结论:七叶洋地黄双苷滴眼液可有效地缓解VDT综合征,临床应用安全。     

维生素B12滴眼液缓解视频终端视疲劳的临床观察

目的：观察维生素 B12滴眼液缓解视频终端视疲劳的临床疗效。
　　方法：纳入患者50例100眼,治疗组及对照组各25例50眼。对照组给予生理盐水点眼,治疗组给予维生素 B12滴眼液点眼。使用方法均为每日3次,每次1滴,点双眼,连续用药60d。测定各组患者用药前后眼调节参数及泪液分泌量。
　　结果：用药后,治疗组与对照组相比泪液分泌量增加,调节幅度加大,调节灵敏度增加,调节滞后减少,差异均具有统计学意义(P<0.05)。
　　结论：维生素 B12滴眼液可以改善干眼症状,提高眼调节能力,治疗视频终端视疲劳。     

Forced vergence fixation disparity parameters with and without a central fusion lock

The effect of a central fusion lock on forced vergence fixation disparity curve parameters, that is, magnitudes of fixation disparity and associated phoria, curve type and the central slope of the curve, was studied in 84 subjects because of ambiguity in the previous studies. It was found that the magnitudes of exo fixation disparity and exo associated phoria decreased significantly when they were measured with the central fusion lock. The central lock had no noticeable effect on the type of the curve, although, the central slope of the curve was flatter in the presence of the central lock.     

Vision Impairment and Driving

Driving is the primary mode of travel in many countries. It facilitates the performance of routine daily activities and is thus integral with the concept of quality of life. Vision is inarguably a fundamental component of safe driving. Drivers with certain eye conditions reduce their driving exposure and restrict their driving to the safest times, yet there is preliminary evidence that some eye conditions increase the risk of crashes. Visual acuity is only weakly related to crash involvement, whereas peripheral vision appears to play a more critical role. Color vision deficiency by itself is not a threat to safe driving. Based on the current literature, it is unclear whether other types of visual sensory impairment have a significant impact on driving safety and performance. Tests of visual attention and processing speed show great promise as methods of identifying high-risk drivers. There is a serious need for well-designed studies in key practical areas, such as the safety of low-vision drivers who use bioptic telescopes, the impact of monocular vision impairment on safety, and the effectiveness of vision rescreening policies after initial licensure. For ophthalmologists to guide patients about driving fitness, valid and reliable assessment tools must be developed and made widely available.     

Association between tear film break up time and blink interval in visual display terminal users

AIM: To investigate the association between tear film break up time (TBUT) and blinking interval in visual display terminal (VDT) users. METHODS: Nine hundred and thirty VDT users underwent dry eye testing, and functional visual acuity (FVA) test. The blinking interval during FVA was compared with TBUT. Subjects with longer blinking interval than TBUT were considered as unstable tear film. Logistic regression analysis revealed the risk factors for unstable tear group. RESULTS: Among 930 workers, 858 subjects (92.3%) participated in this study. Almost 80% of the subjects were categorized into the unstable tear group. Unstable tear group has significantly lower Schirmer values and TBUT (17.5±11.6 vs 21.1±11.5 mm, 3.7±2.6 vs 5.7±2.7s, both P<0.001). There were no significant differences in epithelial staining or severity of symptoms. Logistic regression showed that over 40y was a risk for being unstable tear group [odds ratio (OR)=1.53; 95% confidence interval (CI)=1.06-2.20]. Contact lens use was protective factor for being in the unstable tear group (OR=0.37; 95%CI= 0.26-0.53). CONCLUSION: Subjects with shorter TBUT than blinking interval are prevalent among VDT users. Subjects over the age of 40 shows an increased risk for unstable tear film.     

A Unified Rule for Binocular Contrast Summation Applies to Normal Vision and Common Eye Diseases

PurposeBinocular summation refers to better visual performance with two eyes than with one eye. Little is known about the mechanism underlying binocular contrast summation in patients with common eye diseases who often exhibit binocularly asymmetric vision loss and structural changes along the visual pathway. Here we asked whether the mechanism of binocular contrast summation remains preserved in eye disease.MethodsThis study included 1035 subjects with normal ocular health, cataract, age-related macular degeneration, glaucoma, and retinitis pigmentosa. Monocular and binocular contrast sensitivity were measured by the Pelli-Robson contrast sensitivity chart. Interocular ratio (IOR) was quantified as the ratio between the poorer and better eye contrast sensitivity. Binocular summation ratio (BSR) was quantified as the ratio between binocular and better eye contrast sensitivity.ResultsAll groups showed statistically significant binocular summation, with the BSR ranging from 1.25 [1.20, 1.30] in the glaucoma group to 1.31 [1.27, 1.36] in the normal vision group. There was no significant group difference in the BSR, after accounting for IOR. By fitting a binocular summation model Binocular = (Left^m + Right^m)^1/m to the contrast sensitivity data, we found that the same binocular summation rule, reflected by the parameter m, applies across the five groups.ConclusionsCortical binocular contrast summation appears to be preserved in spite of eye diseases that can affect the two eyes differently. This finding supports the importance of assessing both monocular and binocular functions, rather than relying on a monocular assessment in the better eye as a potentially inaccurate surrogate measure.     

Improving interactive facility with vision training

The measurement of accommodative facility has gained acceptance in optometric examinations because it can provide valuable information on the dynamics of accommodation. Accommodative infacility is usually treated by prescribing various orthoptic exercises. This study arose from a need to investigate the effects of specific vision training procedures on binocular accommodative facility (interactive facility). The results indicate that even relatively short periods of accommodative rock training can improve the level of interactive facility.     

马来西亚一所私立大学使用视觉显示装置的学生非斜视双眼视觉异常

目的：评估马来西亚一所私立大学使用视觉显示装置(VDU)的学生非斜视双眼视觉异常(NSBVA)情况。

方法：对2019-01/2019-05期间每天使用3h及以上VDU的大学生进行横断面研究。使用一种简便的样本收集方法,所有受试者均通过初级视力检查且满足入选标准,对符合入选标准的学生进一步进行NSBVA评估。采用描述性分析排除NSBVA的百分比,采用Chi-square独立性检验,观察NSBVA与年龄、性别、VDU使用时间的相关性。

结果：研究共纳入140名学生,其中女88名(62.9%),男52名(37.1%)。受试者平均年龄为22.54±1.48a,平均VDU使用时间为5.76±2.49h。使用VDU学生的NSBVA百分比为40%。在VDU使用者中,调节异常和倾斜异常的发生率分别为17.86% 和22.14%。性别与NSBVA之间存在适度关联(P=0.010)。但是,年龄(P=0.334)和VDU使用时间(P=0.835)与NSBVA无显著相关。

结论：马来西亚一所私立大学的学生中,有40%的人使用VDU。在所有NSBVA中,VDU用户调节异常(15%)和会聚功能异常(10%)更为常见。     

斜视患者脑功能与结构异常的研究进展

斜视是一种常见的眼球运动障碍,表现为眼位偏斜,常伴双眼视觉功能受损。正常眼位有赖于参与视觉系统和眼球运动系统的各脑区的正常功能和它们之间的协调配合,其中任一层次的受损都可能引起斜视。早期神经电生理和免疫自显影技术应用于动物实验,发现初级视觉皮层功能损伤,包括双眼视神经元减少、眼优势柱代谢改变。近年来,功能磁共振的发展促进了对人脑皮层功能变化的认识。研究发现斜视患者不仅存在与眼球运动及双眼视觉功能障碍相关的脑皮层及皮层间联系的损伤,还存在与代偿相关的可塑性改变。而基于体素的形态计量学和弥散张量成像技术的应用为斜视患者大脑异常提供了解剖学依据。本文从脑功能与结构异常角度对近几年有关斜视神经机制的研究进展进行综述,以期为进一步研究提供参考。     

川东北地区基于某视光门诊的非斜视性双眼视觉异常患病情况及相关因素研究

目的：:调查川东北地区某眼视光门诊12～35岁患者的非斜视性双眼视觉异常（NSBVD）患病情况及相关因素。方法：:系列病例研究。招募于川北医学院附属医院眼视光门诊寻求常规视力检查的12～35岁志愿者172例。检查内容包括主觉验光、立体视觉、水平隐斜、正融像性聚散（PFV）和负融像性聚散（NFV）、聚散灵活度（VF）、集...     

视频终端干眼患者眼表及睑板腺的分析

目的　探讨睑板腺腺体缺失和睑板腺脂质排出难易程度在年轻视频终端干眼患者眼部不适症状中的作用。方法　选择２０１４年１０月至２０１５年１月就诊于天津医科大学眼科医院屈光角膜门诊临床诊断为视频终端干眼的患者５０例（１００眼）。根据视频时间分为２组:短视频组（每天≤４ｈ）２８例、长视频组（每天＞４ｈ）２２例。根据眼表疾病评分指数（ｏｃｕｌａｒｓｕｒｆａｃｅｄｉｓ-ｅａｓｅｉｎｄｅｘ,ＯＳＤＩ）分为２组:轻、中度症状组（１３．０≤ＯＳＤＩ≤３２．５）３０例,重度症状组（３２．５＜ＯＳＤＩ≤１００．０）２０例。利用眼表分析仪及裂隙灯显微镜分别进行泪河高度、泪膜破裂时间、睑板腺、角膜荧光素染色及睑板腺脂质排出状况的评估。根据数据的正态分布和方差齐性,采用两独立样本ｔ检验。结果　长视频组与短视频组ＯＳＤＩ分别为２８．１５±１１．２８、２２．９３±９．７５,泪膜破裂时间分别为（５．８４±１．９５）ｓ、（４．７５±１．５９）ｓ,角膜荧光素染色评分分别为３．０８±１．７０、２．２１±２．０２,睑板腺缺失等级分别为２．５０±１．１１、１．８９±０．９１,睑板腺脂质排出难易度评分分别为２．１１±０．８０、１．７５±０．８６,两组间差异均有统计学意义（均为Ｐ＜０．０５）。长视频组与短视频组泪河高度分别为（０．１９±０．０４）ｍｍ、（０．２０±０．０４）ｍｍ,差异无显著性（Ｐ＝０．０６９）。严重症状组与轻、中度症状组的泪膜破裂时间［（４．６８±１．７７）ｓ、（５．６１±１．８１）ｓ］、角膜荧光素染色评分（３．５０±１．５０、２．１０±２．０１）、睑板腺缺失等级（２．４８±１．０１、２．０５±１．０３）及睑板腺脂质排出难易度评分（２．２３±０．６２、１．８０±０．９０）相比差异均有统计学意义（均为Ｐ＜０．０５）,严重症状组与轻、中度症状组的泪河高度分别为（０．１９±０．０５）ｍｍ、（０．２０±０．０４）ｍｍ,差异无显著性（Ｐ＝０．４２８）。睑板腺缺失与ＯＳＤＩ评分及角膜荧光素染色评分呈正相关（ｒ＝０．２２２,Ｐ＝０．０２６;ｒ＝０．２４１,Ｐ＝０．０１６）;睑板腺脂质排出难易程度与ＯＳＤＩ评分及角膜荧光素染色评分呈正相关（ｒ＝０．２０５,Ｐ＝０．０４１;ｒ＝０．３１１,Ｐ＝０．００２）。结论　视频终端干眼患者泪液量与视频时间和眼部症状严重程度无显著相关性。睑板腺缺失及睑板腺脂质排出难度增加可能是引起视频终端干眼眼部不适的重要因素。     

Preschool visual acuity tests: A comparison between two prototype charts and two visual acuity charts in current use

The lack of standardised visual acuity charts with established norms for preschool children has resulted in a diverse variety of visual acuity tests in use for the paediatric patient. All available tests appear to have some limitations, including inadequate norms, long test times, poor reliability, and frequently use test parameters and stimuli which are different from those used with adults. This study compares results for four visual acuity test charts. A Bailey-Lovie Illiterate E chart and an abbreviated Sheridan-Gardiner test were compared with two prototype acuity charts; a modified Bailey-Lovie letter chart and an Arrow chart. A novel symbol such as an arrow constructed as a Snellen optotype incorporated into a chart on the Bailey-Lovie principle, was the test of choice. This test was interesting to preschool children and results showed significant correlation with those obtained using charts based on adult standards.     

Poor Vision and Self-Reported Functional Difficulties among Recently Hospitalized Individuals in the United States

Purpose: Many hospitalized adults may have limited vision and as a result be at increased risk of worse functional outcomes. Here, we determine the prevalence of poor vision among recently hospitalized United States adults. Additionally, we evaluate the impact of objective vision defects on reading difficulty and external mobility outcomes (difficulty with falls and going down steps).

Methods: Our cross-sectional study included 1,347 adult Americans aged 50 years and older, all recently hospitalized, participating in the 2001–2008 National Health and Nutrition Examination Survey (NHANES). Self-reported difficulty with reading and going down steps/stairs/curbs data were collected for all participants, while data on self-reported falling difficulty were only available for the 2001–2004 NHANES (n=631). Presenting near and distance visual acuity (VA) were measured, with poor vision defined as VA worse than 20/40.

Results: Poor near and distance vision were present in 17.4% and 9.8% of individuals, respectively. Multivariable analyses showed that the odds of reading difficulty were greater with worse VA (odds ratio, OR, 1.9 per 0.3 logMAR increment in near VA, 95% confidence interval, CI, 1.6–2.4, P<0.01), as were the odds of difficulty going down steps/stairs/curbs (OR 2.4 per 0.3 logMAR increment in distance VA, 95% CI 1.9–3.1, P<0.01) and odds of falling difficulty (OR 1.6 per 0.3 logMAR increment in distance VA, 95% CI 1.1–2.4, P=0.04).

Conclusion: About 1 in 10 and 1 in 6 recently hospitalized older Americans had poor distance and near vision, respectively. Many of these individuals may experience trouble reading hospital documents and ambulating, and may be at increased risk of falls.