使用计算机终端及不同休息方案对眼表性状的影响

目的 研究使用计算机终端及不同的休息方案对眼表性状的影响.方法 30名受试者均接受5种不同阅读方案:1.连续计算机终端阅读2h后休息10min.(2)连续书本阅读2h后休息10min.(3)连续计算机终端阅读1h后休息10min(休息1方案).(4)计算机终端阅读总时间1h,每30min间隔休息5min(休息2方案).(5)计算机终端阅读总时间1h,每15min间隔休息2min(休息3方案).每次阅读前后分别检查眼部泪膜破裂时间(Brakup Time,BUT)、基础泪液分泌试验(Schirmer I test,Sit)、角膜荧光素染色(Fluorescein Staining,FL)、虎红(Rose Bangle,Rb)染色、结膜印迹细胞(Imprssion Cytology,IC)检查.结果 (1)连续2h计算机终端阅读后较书本阅读更易出现BUT缩短、Sit值减少、FL及Rb染色评分增加(P<0.05).(2)连续计算机终端阅读2h较1h更易出现BUT缩短Sit值减少、FL及Rb染色评分增加(P<0.05).(3)3种休息方案之间的BUT、FL、Rb染色之间的差异具统计学意义(P<0.05),休息3方案优于其它方案.结论 使用计算机终端阅读较书本阅读更易对眼表性状产生影响,并随时间的不同出现差异.三种不同休息方案比较,每使用计算机终端阅读15min间隔休息2min(休息3方案)对眼表性状影响最小.     

非斜视性双眼视觉异常临床分析

目的 对5例不同的非斜视性双眼视觉异常的视功能检测结果进行综合分析.方法 对2012年4月至2013年4月在南昌大学附属眼科医院在验光基础上,应用综合验光仪测量集合幅度、调节幅度以及正负相对调节,用Von Graefe法测量在远近距离的隐斜方向和隐斜度、调节集合/调节值(AC/A)比率(调节性集合与调节量之比),用Risley可变棱镜测量远近水平正负融像聚散,用Worth4点灯和R.D.S立体视觉图测量立体视觉.参照Morgan分析法加以分析并采取相应视觉训练.结果 (1)1例集合不足的特征是远距隐斜在正常范围而近距高度外隐斜,且近距正相对聚散(PRC)低、AC/A低.(2)1例集合过度是近距内隐斜、远距隐斜在正常范围、负相对聚散(NRC)低、AC/A高.(3)1例散开过度是远距高度外隐斜、近距隐斜在正常范围、高AC/A.(4)1例融像性聚散减低是远、近距隐斜均在正常范围,AC/A正常、但正负融像性聚散均下降.(5)1例单纯内隐斜是远、近距内隐斜均超过正常范围,负相对聚散下降、AC/A正常.结论 5例都属于非斜视性双眼视觉异常,临床症状虽相似,检查结果却不同,诊断和治疗也不尽相同.     

配戴多焦点硬性角膜接触镜对近视患者双眼视功能的影响

目的：探讨多焦点设计的硬性角膜接触镜对近视患者双眼视功能的影响。

方法：自身前后对照研究。于2020-07/08在川北医学院招募近视学生15人作为试验者,试验者首先配戴框架眼镜行双眼视功能检查,然后分别配戴单焦点与多焦点硬性角膜接触镜(间隔1wk),每种镜片配戴2wk后行双眼视功能检查。采用单因素方差分析比较多焦点硬性角膜接触镜(MFRGP)、单焦点硬性角膜接触镜(SVRGP)和框架眼镜双眼视功能的差异。

结果：三种镜片立体视、远距水平隐斜、远距正融像性聚散、远距负融像性聚散、近距正融像性聚散、聚散灵活度、集合近点、调节幅度、调节灵活度、负相对调节比较均无差异(P>0.05)。与框架眼镜相比,配戴MFRGP近距水平隐斜、近距负融像性聚散、调节滞后、正相对调节增大,AC/A降低(P=0.023、0.048、0.001、0.013、0.046); 与SVRGP相比,MFRGP近距水平隐斜、调节滞后、正相对调节增大,AC/A降低(P=0.014、<0.001、0.001、0.009)。

结论：配戴MFRGP会引起近距水平隐斜、调节滞后、正相对调节增大和AC/A降低,这些变化可能对配戴者近距离用眼产生一定影响,在临床应用中要考虑这些预期的变化,以便正确评估和管理患者。     

注视视频终端对视觉功能的影响

目的 了解短期注视视频终端（VDT）对视功能和眼生理的影响。方法 选择21名受试者,进行持续1h的计算机操作（注视VDT）,操作前后分别行验光、调节幅度、集合近点、AC／A、远及近距离水平隐性斜视、正负融像性聚散能力、泪膜破裂时间（BUT）及像差测定,并与该组受检者近距离书本阅读进行比较。结果 VDT操作后受试者较近距离书本阅读更易出现调节幅度降低、集合近点远离、近距离外隐性斜视幅度增加,前后比较差异有统计学意义（P〈0．05）;VDT可使BUT缩短,像差增加,前后比较差异有统计学意义（P〈0．05）。但AC／A、正负融像性聚散能力、远距离隐性斜视幅度的差异无统计学意义（P〉0．05）。结论 VDT操作较书本阅读更易对人视觉功能产生影响,VDT操作可对泪膜性状和视觉质量产生暂时的影响。     

计算机阅读后的调节幅度与屈光度优势眼的关系

目的 研究计算机阅读后的单眼调节幅度及其变化与屈光度、优势眼的关系.方法 30名受试者按不同屈光度、屈光参差状态、优势眼分组,均作连续计算机终端阅读2h,阅读前后分别查单眼调节幅度.结果 (1)连续2h计算机阅读前,调节幅度的大小与屈光度有相关性(r=0.439,P=0.003);阅读后,调节幅度的变化与屈光度无相关性(r=0.121,P=0.434).(2)计算机终端阅读前,优势眼的调节幅度大小与非优势眼调节幅度大小比较差异无统计学意义(P＞0.05);阅读后,优势眼的调节幅度变化比非优势眼调节幅度变化大(P＜0.05).(3)生理性屈光参差组和病理性屈光参差组两组内优势眼眼别与双眼中屈光不正度数较高或较低眼别之间无相关性(P＞0.05).结论 计算机阅读前,调节幅度的大小与屈光度有相关性;计算机阅读后优势眼的调节幅度变化比非优势眼调节幅度变化大;优势眼眼别与双眼中屈光不正度数较高或较低眼别之间无相关.高调节幅度及优势眼可能并不是近视进展中的主要因素.     

Effects of persistent viewing of 3 D TV on human visual function

目的:研究持续观看3D电视对视功能的影响,以及探索不同视功能参数之间的关系.方法:本研究录入19位受试者,每位受试者观看90分钟的2 D电视或90分钟的3 D电视,两部电视观看间隔时间为一周,顺序随机.每次观看电视前及观看后15 min内都做相关视功能检查,检查包括以下四种视功能参数:调节功能(调节反应、调节微波动、调节灵敏度、正相对调节、负相对调节、AC/A),融像性聚散功能(远距负融像性聚散功能、远距正融像性聚散功能、近距负融像性聚散功能、近距正融像性聚散功能),隐斜量(远距隐斜量、近距隐斜量),立体视.结果:无论是与观看前的基础值比较,还是与观看2D电视后的数据比较,观看3D电视后近距离调节反应增加,汇聚减少,远距隐斜量向外隐斜改变(P<0.05).结论:持续观看3D电视会对人们的视功能有一定影响,主要是打破了调节和聚散系统的平衡.厂家和公众应该引起重视,将调节功能、融像性聚散功能、隐斜量等参数作为评估3D电视安全性的指标.     

近视儿童调节滞后与隐斜状态及相关因素研究

目的 研究近视儿童近距注视下的调节滞后和隐斜量,分析近视儿童调节滞后与近隐斜的关系及相关因素.方法 受试者为250名近视儿童,等效球镜屈光力范围为-0.50～-5.25D.采用MEM动态检影法测量受试者右眼近距的调节滞后;分别采用Howell测量法(HT)和改良Thorington测量法(MTT)测量近隐斜;通过问卷调查受试者父母的屈光状态.各重复测量三次,取均值.结果 受试者近距调节滞后为(+0.97±0.43)D,近隐斜为(-0.94±4.55)△(外隐斜,HT)和(-1.71±4.85)△(外隐斜,MTT).伴近内隐斜者占28.0％(HT)和22.8％(MTT).伴近内隐斜者的调节滞后和内隐斜呈正相关(r=0.353,P=0.003,HT;r =0.461,P＜0.001,MTT);受试者调节滞后和近视程度呈负相关(r=-0.241,P＜0.001).23％近视者父母均为近视,其调节滞后显著大于其父母组儿童(F =4.90,P=0.009).结论 近视儿童在近距注视状态下调节滞后较高.近隐斜状态和遗传因素都可能影响近视儿童的调节滞后,调节滞后量与近视程度可能存在相互作用.临床上应将近距调节反应和隐斜测量纳入儿童的常规视功能检查项目.     

集合不足型外隐斜合并调节不足三种治疗方法的比较

目的 比较集合调节训练、三棱镜配戴矫正和近视屈光过矫在集合不足型外隐斜合并调节不足患者中的疗效.方法 横断面研究,将10～35岁的60名确诊为集合不足型外隐斜合并调节不足患者随机分为3组,每组20例,A组行三棱镜配戴矫正,B组行近视屈光过矫-0.50 D戴镜矫正,C组行集合调节视功能训练,于3个月后复查隐斜度和视功能采用配对t检验和单因采方差分析 结果 复查各项视功能参数3组患者之间差异有统计学总义 A组患者隐斜度增加(t=1 2.65,P＜0.01),近距正相对融合范围减小(t=12.65,P＜0.01),症状先短暂缓解后加重;B组患者隐斜度增加(t=4.63,P＜0.01),近距正E相对融合范围减小(t＝6.71,P＜0.01),调节幅度减小(t=14.3,P＜0.01),症状明显加重;C组患者隐斜度显著减小(t=-11.61,P＜0.01),近距正相对融合范围显著增大(t=-22.40,P＜0.01),调节幅度显著增大(t=-31.06,P＜0.01),症状明显改善 结论 集合不足型外隐斜合并调节不足患者采用集合调节视功能训练能明显改善症状,减少近距隐斜度,增加近距正相对融合范围和调节幅度,是一种有效可行的治疗方法.     

注视视频终端对眼健康的影响

目的:了解长时间注视视频终端(video display terminal,VDT)对眼健康的影响,并提出预防对策。方法:对长时间连续注视VDT者视功能、屈光状态及眼进行检查,测定调节幅度、集合近点,并与很少或不操作VDT者的同样检查或测定情况进行对比。结果:长时间连续注视VDT者,其眼的健康比非注视VDT者更容易出现眼痛、眼胀、视物模糊、视力下降等视疲劳现象,并且随注视时间的延长,视疲劳的倾向更明显,调节幅度降低,集合近点远离。两组比较差异有统计学意义(P<0.05)。结论:长时间连续注视视频终端较阅读书本等界面更易对眼产生负面影响,应加强预防VDT性眼健康损害。     

持续观看立体(3D)视频对人眼视觉功能的影响

目的 研究持续观看立体(3D)视频(采用快门式立体电视)对人眼调节、聚散、立体视觉等视功能及主观视疲劳症状的影响.方法 招募32名受试者,在暗环境下配戴快门式立体眼镜持续观看90 min立体电视,在观看前后分别测量调节反应、调节微波动、调节幅度、调节灵活度、正负相对调节、梯度性AC/A、集合近点、远及近距离水平隐斜视、正负融像性聚散能力、立体视觉等双眼视功能重要参数,以及完成观看后的主观视疲劳问卷调查.结果 在持续观看立体(3D)视频后,受试者近距离调节反应[40 cm:观看前(1.58±0.33)D,观看后(1.67±0.31)D;25 cm:观看前(2.41±0.40)D,观看后(2.54±0.37 D)]和调节微波动[25cm:观看前(0.17士0.07)D,观看后(0.23±0.13 D)]均增加,内隐性斜视者的远、近距离隐斜视幅度[远距:观看前(1.96±1.71)△,观看后(0.36±1.21)△;近距:观看前(4.64±3.73)△,观看后(2.14±3.75)△]均减小、近距正融像性聚散能力[观看前(26.75±7.39)△,观看后(23.30±9.68)△]减低,观看前后差异均有统计学意义(均为P＜0.05),且观看后多数人(91％)出现视疲劳症状,其中视远模糊、眼干等症状比较突出.结论 持续观看立体(3D)视频会对人眼视功能产生一定影响,并可诱导出现不同程度的视觉疲劳症状.     

Binocular function in school children with reading difficulties

Introduction  

Prior findings suggest that poor readers tend to have poor binocular vision skills, but data on the binocular abilities of children with poor reading skills are lacking. Our aim was to characterize distance and near horizontal heterophoria, distance and near horizontal fusional vergence ranges, accommodative convergence/accommodation (AC/A) ratio, near point of convergence, and stereopsis in poor-reading school-age children without dyslexia selected from a non-clinical population.     

不同程度近视青少年儿童双眼视功能的差异

目的通过比较不同程度近视儿童双眼协动参数的差异性及其与近视程度相关性,进一步探索近视发展的原理。方法横断面研究。研究对象包括128例7～14岁近视青少年儿童,根据等效球镜度分为低度近视组（-0.50～-3.00 D）、中度近视组（-3.25～-6.00 D）和高度近视组（>-6.00 D）。双眼协动参数测量包括远距及近距水平聚散力,远距及近距水平隐斜,梯度性调节性集合与调节的比率（AC/A比率）。采用单因素方差分析和卡方检验对3组数据进行分析。结果在融像性聚散范围中,远距散开力的破裂点、近距散开力的恢复点、远距集合力的恢复点、近距集合力的模糊点及破裂点随近视程度加深而减小（F=3.271、3.579、4.931、6.507、4.887,P<0.05）,其余参数的差异无明显统计学意义（P>0.05）;在隐斜视类型的构成比中,远距及近距隐斜类型构成比例的差异在3组中无明显统计学意义（P>0.05）,总体上近距内隐斜构成比例高于远距内隐斜（χ²=6.609,P<0.05）;梯度性AC/A随近视程度的增加而增加（F=3.625,P<0.05）,其中高度近视组明显高于低度近视组（P<0.05）。结论随着青少年儿童近视程度的增加,融像性聚散范围减少,梯度性AC/A比率增高。近视儿童表现出的近距内隐斜可能与近视发展相关。     

Contact lenses vs spectacles in myopes: is there any difference in accommodative and binocular function?

Background  

Theoretically, the accommodative and vergence demands are different between single-vision contact lenses and spectacle lenses. The aim of the present study was to determine whether these differences exist when these two correction methods are used in clinical practice. For this, different visual parameters that characterize the accommodative (accommodation amplitude, accommodative facility, and accommodative response) and binocular function (near and distance horizontal and vertical dissociated phorias, near and vertical associated phorias, near and distance negative and positive fusional vergence, vergence facility, near point of convergence, negative and positive relative accommodation, stimulus AC:A ratio and stereoacuity) were evaluated in a student population when their myopia was corrected with either spectacles or soft contact lenses (SCL).     

Evidence that convergence rather than accommodation controls intermittent distance exotropia

Purpose: This study considered whether vergence drives accommodation or accommodation drives vergence during the control of distance exotropia for near fixation. High accommodative convergence to accommodation (AC/A) ratios are often used to explain this control, but the role of convergence to drive accommodation (the CA/C relationship) is rarely considered. Atypical CA/C characteristics could equally, or better, explain common clinical findings. Methods: Nineteen distance exotropes, aged 4-11?years, were compared while controlling their deviation with 27 non-exotropic controls aged 5-9?years. Simultaneous vergence and accommodation responses were measured to a range of targets incorporating different combinations of blur, disparity and looming cues at four fixation distances between 2?m and 33?cm. Stimulus and response AC/A and CA/C ratios were calculated. Results: Accommodation responses for near targets (p?=?0.017) and response gains (p?=?0.026) were greater in the exotropes than in the controls. Despite higher clinical stimulus AC/A ratios, the distance exotropes showed lower laboratory response AC/A ratios (p?=?0.02), but significantly higher CA/C ratios (p?=?0.02). All the exotropes, whether the angle changed most with lenses ('controlled by accommodation') or on occlusion ('controlled by fusion'), used binocular disparity not blur as their main cue to target distance. Conclusions: Increased vergence demand to control intermittent distance exotropia for near also drives significantly more accommodation. Minus lens therapy is more likely to act by correcting overaccommodation driven by controlling convergence, rather than by inducing blur-driven vergence. The use of convergence as a major drive to accommodation explains many clinical characteristics of distance exotropia, including apparently high near stimulus AC/A ratios.     

Stimulus and response AC/A ratios in intermittent exotropia of the divergence-excess type.

Objective infrared recording devices were used to measure simultaneously and continuously both accommodation and accommodative vergence to near stimuli in 4 subjects with intermittent exotropia of the divergence-excess type (2 simulated and 2 true). In addition standard clinically determined stimulus accommodative convergence to accommodation (AC/A) ratios were measured. Results showed the mean group response AC/C ratio to be 5.9/1 (range 4.5-8.0/1) with no differences between true and simulated divergence-excess. Similar AC/A ratios were found after 45 minutes of monocular occlusion. Our results clearly demonstrate relatively normal response AC/A ratios in these subjects. Thus, contrary to what is believed by many clinicians, the reduced ocular deviation at near compared with distance vision cannot be attributed primarily to an abnormally high AC/A ratio. We believe than fusional convergence after-effects and/or proximal convergence effects contribute to inflate the clinically determined stimulus AC/A ratios.     

Changes in vergence and accommodation parameters after smartphone use in healthy adults

Purpose:To assess pre and post vergence and accommodation parameters after monitored reading on a smartphone device.Methods:This prospective comparative study was performed in a tertiary eye care center for a duration of 6 months (December 2017 – May 2018). A total of 47 healthy emmetropic subjects of age group ranging from 18-30 years were recruited for the study. Participants underwent an initial visual screening protocol, followed by accommodation and vergence parameters assessment. The subjects were given reading text of optotype N6 at 40cm working distance for 30 minutes in a smart phone device. Pre and post measurements were documented.Results:Among 47 subjects there were 17 male and 30 females with mean age group of 21.2+2.06 years. There was a statistically significant worsening of accommodative components (negative & positive relative accommodation, lag of accommodation). In vergence parameters, a statistically significant deterioration of negative (12.8 + 1.65 to 12.38 + 1.93 PD) and positive fusional vergence (15.48 + 1.53 to 16.08 +1.61 PD) was observed. The mean vergence facility also showed a statistically significant change in pre and post task measurements (13.51 + 1.64 to 10.71 + 1.91 cpm (cycles per minute)).Conclusion:The current study investigated that perusing text with a smart phone for 30 minutes shows significant effect on accommodative and vergence components for near task, with greater impact on vergence parameters. Drawn out exposure to digital screens at near, may bring about visual quality dysfunction.     

Effects of wearing yellow spectacles on visual skills, reading speed, and visual symptoms in children with reading difficulties

Background

Possible beneficial effects of yellow-tinted spectacle lenses on binocular vision, accommodation, oculomotor scanning, reading speed and visual symptoms were assessed in children with reading difficulties.

Methods

A longitudinal prospective study was performed in 82 non-dyslexic children with reading difficulties in grades 3–6 (aged 9–11 years) from 11 elementary schools in Madrid (Spain). The children were randomly assigned to two groups: a treatment (n?=?46) and a without-treatment group (n?=?36). Children in the treatment group wore yellow spectacle lenses with best correction if necessary over 3 months (in school and at home). The tests were first undertaken without the yellow filter. With best spectacle correction in each subject, measurements were made of: distance and near horizontal heterophoria, distance and near horizontal fusional vergence ranges, the accommodative convergence/accommodation (AC/A) ratio, near point of convergence (NPC), stereoacuity, negative relative accommodation (NRA) and positive relative accommodation (PRA), monocular accommodative amplitude (MAA), binocular accommodative facility (BAF), oculomotor scanning, and reading speed (words per minute). The Convergence Insufficiency Symptom Survey (CISS) questionnaire was completed by all children. After the 3-month period, measurements were repeated with the yellow lenses (treatment group) or without the yellow lenses (without-treatment group) but with refractive correction if needed.

Results

Over the 3 months, the two groups showed similar mean changes in the variables used to assess binocular vision, accommodation, oculomotor scanning, and reading speed. However, mean relative changes in convergence insufficiency symptoms differed significantly between the groups (p?=?0.01).

Conclusion

No effects of wearing yellow spectacles emerged on binocular vision, accommodation, oculomotor scanning, and reading speed in children with reading difficulties. The yellow filter had no effect even in children with low MAA and BAF. The reduction in visual symptoms observed in children with reading difficulties using the yellow filters was clinically insignificant.