Validity and reliability study of Turkish version on low vision with quality of life questionnaire

AIM:To adapt the low vision-related quality of life(LVQOL) instrument into Turkish language and to assess its validity and reliability.METHODS:The study was conducted in 387 patients attending the Centre of Low Vision Rehabilitation,Faculty of Medicine,Ankara University.For statistical analyses,the Spearman's correlation coefficient,Cronbach's alpha coefficient and Confirmatory Factor Analysis(CFA) were used.RESULTS:According to results of CFA,the item in the 'Adjustment' subscale because of having the factor loading below 0.40,was excluded from the questionnaire.The reliability of the questionnaire was assessed according to Cronbach's alpha coefficients.The reliability of the 'Distance Vision,Mobility,and Lighting' subscale was ?琢=0.863;of the 'Adjustment' subscale was ?琢=0.694;'Reading and Fine Work' was ?琢=0.791,and 'Activities of Daily Living' was ?琢= 0.770.So these results indicate that the questionnaire is reliable to measure the vision related quality of life of low-vision patients.The correlations between the subscales were also analyzed,and the correlation between 'Adjustment' and 'Reading and Fine Work' was found to be the lowest(rs=0.336,P <0.001),whereas the strongest correlation was found between the 'Reading and Fine Work',and 'Activities of Daily Living'.Additionally,the 'Adjustment' dimension showed the strongest correlation with only 'Distance Vision,Mobility,and Lighting' dimension.CONCLUSION:After removing the last item in the second dimension,the Turkish adaptation of all dimensions of the LVQOL has been shown to be reliable,valid and suitable for use in patients with low vision in Turkey.

AB097.Barriers and facilitators related to the use of optical low vision aids,a scoping review

Background:In recent decades,several studies have been performed in the field of(non-)use of assistive technology devices(ATs)and have found that many variables are likely to be involved in the decision-making process of whether a person with a disability uses or abandons their aids.In low vision rehabilitation,high variability rates and a variety of reasons for non-use of low vision aids has been reported.Determinants of non-use of ATs have previously been categorized into personal factors,ATs factors,environmental factors of the user,and intervention factors.It is probable that some of these factors are also associated with the use of optical low vision aids(OLVAs).Thus,using a framework about adherence with medical interventions,the aim of this scoping review was to explore barriers and facilitators related to OLVAs(non-)use.Methods:Existing guidelines of the scoping review Methods were used to examine and summarize the extent,range,and nature of findings regarding factor categories associated to OLVAs usage.Searches were conducted using the following online databases:Embase,MedLine,and ERIC without limitation on publication dates.A combination of key words and MeSH terms was used based upon the identified core concepts of the research question:(I)low vision;(II)assistive technology;and(III)adherence.A charting form,a flow chart of the study selection process,and a combination of a descriptive numerical analysis and a thematic analysis of 24 studies were performed.Results:The results of this review indicate high variability rates(range:13-50%,M=24%,SD=10%)of people possessing OLVAs but not using them.Most authors do not use a precise definition of“non-use”,and when a definition is provided,the terminology is inconsistent.As expected,the four categories of variables identified are likely to be involved in OLVAs’(non-)use:(I)the largest number of concerns were personal factors.Several aspects regarding personal characteristics were identified,such as demographic,physical,psychological,social-emotional,and occupational factors.Some variables,such as age,diagnosis and visual acuity were reported as contradictorily influencing the OLVAs’usage;(II)ATs factors were associated with quality,appearance,practical aspects of use and the very type of OLVAs;(III)environmental factors referred to social support,physical barriers,expectations of the social environment,presence of a helper,and stigmatization;(IV)finally,intervention factors consisted of taking into account user’s opinions,positive health care experiences,instruction and training,provision processes,delivery periods,and follow-up services.Conclusions:This scoping review provides the preliminary evidence that factors related to OLVAs non-use could be classified into the same four typical categories described in the theory of non-adherence.These results suggest that strategies intended to enhance adherence might be for OLVAs should focus on these four aspects of device use.

VISUAL REHABILITATION IN LOW VISION PATIENTS WITH AGE-RELATED MACULAR DEGENERATION

Using optical visual aids, visual rehabilitation was performed in 14 low vision patients(25 eyes) with age-related macular degeneration. With distance aids, visual acuity improvement appeared in 24 eyes(95%) out of the 25 eyes. Twelve eyes(48%) obtained a visual acuity equal to or better than 0.4. With near visual aids, near acuity of all eyes(100%) was improved. Thirteen eyes(52%) got the near vision equal to or better than 0.5. Ten patients could read No.5 Chinese Reading Card. The reading success rat...

Prevalence and risk factors for eye diseases, blindness, and low vision in Lhasa, Tibet

AIM: To determine the prevalence and risk factors for eye diseases, blindness, and low vision in Tibet, and to assist the development of eye disease prevention and treatment schemes.METHODS: We carried out a survey of eye diseases among a population living at high altitude. A total of 1 115 Tibetan permanent residents aged 40 years or older from the towns and villages of Qushui County, Lhasa Prefecture, Tibet Autonomous Region, participated in this study. All participants completed a detailed questio-nnaire, and underwent presenting and pinhole visual acuity tests,and a comprehensive ophthalmic examination.RESULTS: There were 187 blind eyes (8.43%), 231 eyes with low vision (10.41% ). The leading cause of visual impairment was cataract of 55.0% (101/187) blindness and of 50.2% (116/231) low vision, followed by fundus lesions of 22.9% blindness and 23.8% low vision, while only a low prevalence of glaucoma of 9.6% blindness and 1.7% low vision was observed. The analysis of 2 219 eyes showed that the most common external eye disease was pterygium (27.2%) in Tibet.CONCLUSION: The high prevalence of blindness and low vision in the Tibetan population at high altitude is a serious public health issue. There is a need to establish and maintain an appropriate effective eye care program in Tibet.

Responsiveness and minimal clinically important difference of the Chinese version of the Low Vision Quality of Life Questionnaire after cataract surgery

AIM: To investigate the Chinese version of the Low Vision Quality of Life Questionnaire(CLVQOL) as an instrument for obtaining clinically important changes after cataract surgery.METHODS: Patients underwent cataract surgery in Shanghai General Hospital, Shanghai Jiao Tong University, who fit the inclusion criteria were recruited. Two CLVQOLs were administered, including a preoperative CLVQOL and a CLVQOL at the end of the 3 mo follow-up period, and were completed using face-to-face interviews or phone interviews conducted by trained investigators. The minimal clinically important difference(MCID) was calculated using an anchor-based method and a distribution method. In addition, the responsiveness of the questionnaire was measured.RESULTS: A total of 155 residents were enrolled. The average visual acuity(VA) preoperatively was 0.08(SD=0.05), and it increased to 0.47(SD=0.28) at the end of followup. Statistically significant positive changes in the CLVQOL scores indicated significant improvement of vision related quality of life after cataract surgery. With the larger value between the two results as the final value, the MCID values of the CLVQOL(scores of the four scales as well as the total score) were 8.94, 2.61, 4.34, 3.10 and 17.63, respectively. The CLVQOL has both good internal and external responsiveness.CONCLUSION: CLVQOL scores are appropriate instruments for obtaining clinically important changes after cataract surgery. This study is an effective exploration for establishingcataract surgery efficacy standards, which helps clinical and scientific research workers in ophthalmology to gain a more in-depth understanding when using CLVQOL.

Functional outcome of the low vision aids for visual impairment secondary to central nervous system tumors in children

To assess functional outcomes of optical low vision aids(LVAs) for pediatric visual impairment due to central nervous system(CNS) tumors. A prospective case study was conducted on 15 children with history of CNS tumors with mean age of 10.47±1.85 y. Lighthouse distance, near visual acuity tests, cycloplegic refraction, reading speed measurement and visual field examination were done. Prescription of far and near LVAs followed by training sessions. LVPrasad-functional vision questionnaire was done to evaluate performance. Visual impairment was moderate(13.3%), severe(73.3%), profound(6.7%) and near blindness in 6.7%. Telescopes prescribed in 33.4%, video magnifier in 46.7%. Questionnaire scores were significantly improved for distant rather than near tasks(P≤0.05) after training. LVAs rehabilitation is an effective method of improving vision in pediatric visual defects secondary to CNS tumors.

Machine Vision Based Measurement of Dynamic Contact Angles in Microchannel Flows

When characterizing flows in miniaturized channels, the determination of the dynamic contact angle is important. By measuring the dynamic contact angle, the flow properties of the flowing liquid and the effect of material properties on the flow can be characterized. A machine vision based system to measure the contact angle of front or rear menisci of a moving liquid plug is described in this article. In this research, transparent flow channels fabricated on thermoplastic polymer and sealed with an adhesive tape are used. The transparency of the channels enables image based monitoring and measurement of flow variables, including the dynamic contact angle. It is shown that the dynamic angle can be measured from a liquid flow in a channel using the image based measurement system. An image processing algorithm has been developed in a MATLAB environment. Images are taken using a CCD camera and the channels are illuminated using a custom made ring light. Two fitting methods, a circle and two parabolas, are experimented and the results are compared in the measurement of the dynamic contact angles.

Low Vision Assessment: Complications from Juvenile Rheumatoid Arthritis

Background: Juvenile Rheumatoid Arthritis (JRA) is an inflammatory disease that affects the joints of children and is associated with ocular complications, like uveitis and cataract. Patients with such complications can benefit from a low vision assessment to improve their functionality and their quality of life. In this case study, the importance of early detection and management of ocular complications of JRA, as well as visual rehabilitation through a low vision assessment, are highlighted and discussed. Case Presentation: A 12-year-old female of East Indian descent presented to the Low Vision Center of the University of the West Indies Optometry Eye Unit, bilaterally aphakic (absence of crystalline lens) as a result of complications she developed secondary to a systemic condition diagnosed as JRA. She presented with a distance visual acuity of 2.30 logMAR in the RE, and 1.64 logMAR in the LE, at near she was able to read 8.0 M and 3.2 M at a distance of 8 cm for RE & LE respectively. She has a history of ocular disorder secondary to JRA such as cataract, uveitis, upon low vision assessment a new spectacle prescription and an illuminated stand magnifier of 8D was issued, the patient was satisfied with the outcome of the treatment, management and low vision device issued. Conclusion: At the end of the low vision assessment, the patient was extremely satisfied and looked forward to the prospect of returning to school. Although JRA can have severe ocular complications, with the correct management, a patient’s quality of life can be dramatically improved thus stressing the importance of these types of visual assessments.

Profile of Low Vision Patients in a Resource-Poor Underserved Setting of a Developing Country

Objectives: To identify causes of low vision among the patients in the Eye clinic of University of Nigeria Teaching Hospital (UNTH). Methods: This was a cross-sectional study of all new consecutive low vision patients seen at the eye clinic of University of Nigeria Teaching Hospital-(UNTH) Ituku-Ozalla. All patients with low vision were evaluated by the researcher and the findings entered on a research protocol. Data were analyzed using descriptive statistics to generate frequency and percentage distributions and analytical statistics to test for significance of observed inter-group differences. In all comparisons, statistical significance was indicated by p < 0.05. Results: A total of 197 patients were seen comprising of 120 males and 77 females (M:F = 1.6:1) aged 39.3 ± 22.9 SD years. The main causes of low vision in the study population were glaucoma (36.0%), followed by oculocutaneous albinism (14.7%). The mean presenting distant VA was logMAR 1.1 (95% CI), while the mean near VA is logMar 1.0 (6/60, 20/200). After refraction, the mean distant VA was logMar 1.0, using unpaired t-test, the difference between the distant presenting and refracted VA were not statistically significant. 57.9% had distant VA after optical low vision assessment of logMar 0.9 - logMar - 0.2 while the mean distant VA was logMar 0.8 which was statistically significant. Near vision after optical assessment improved with a mean of logMar 0.8, which was statistically significant. Conclusion: Glaucoma was the commonest cause of low vision in this study. Optical low vision aids improved the visual functions of majority of the patients in this study.

The Contrast Sensitivity Function in Low Vision

The contrast sensitivity of 51 low vision patients (95 eyes) showed a substantial decrease in all spatial frequencies. The peak contrast sensitivity was shifted to 1 C/D from the normal 3-4 C/D. The high-frequency cut off is correlated to the visual acuity positively. Of the 33 patients, the preferred eye was the eye with better peak sensitivity in 28 patients (84%), while the preferred eye was the eye with better visual acuity in 22 patients (66%). It seems that the peak sensitivity is more important t...

Quantitative Evaluation of Flicker ERG Waveforms in Low Vision Patients

Flicker electroretinograms(FERGs)of 30Hz were recorded for 46eyes(23 cases)of low vision,including 38 eyes with retinal diseases and 8eyes with optic neuropathy,and for 39 normal eyes(33 cases).The recordedwave forms were analysed by two methods:(1)to measure the peak to peakamplitude and pseudophase directly,and(2)to measure the amplitude andphase of fundamental response component(30Hz)by discrete Fourier trans-form(DFT).The abnormality ratios between these two methods were com-pared in low vision pati...

"Made in China" Reflects Low Added-value in Global Industrial Divisions

The Belle Corporation is a Chinese domestic shoe maker and seller. It also belongs to an industry that has come to be representative of the ubiquitous "Made in China" label. One of the main reasons the company is favored by global investors is due to its unique business pattern-a pattern that sets manufacturing as its base and is active in exploring industrial chain downstream links and establishing its own individual retail channels. Ever since its first inception in the stock market, Belle has set out to acquire several upstream manufacturing companies, indicating its desire for increasing channel terminals. Using a vertically integrated competition strategy, Belle stands out amongst its rivals as being particularly successful in the non-mainstream manufacturing sector. Consequently, its business practices can be used as a model for other domestic manufacturing companies in their efforts to meet the challenges posed by globalization.

Low Noise Amplifier Design for Digital Television Applications

The DVB-T (Digital Video Broadcasting—Terrestrial) standard is being deployed in many parts of the world for digital broadcasting services, providing a variety of features extending the capabilities of the older analog ones. In this paper, a two-stage low noise amplifier (LNA) is designed for use with the DVB-T standard. The design is employed based on microstrip. The microwave design meets all the specifications required, achieving input and output return loss below ?10 dB, high gain of 35 dB and high linearity. Low noise figure of 1.3 dB is achieved with the use of pHEMT transistor technology.

Prevalence of Charles Bonnet syndrome in low vision:a systematic review and meta-analysis

Background:Charles Bonnet syndrome(CBS)is characterized by vivid lifelike visual hallucinations and is typically seen in individuals with visual impairment.In this systematic review,we summarize current knowledge on the prevalence of CBS in patients with low vision.Methods:We searched 11 literature databases on 21 April 2021 for studies on the prevalence of CBS in low vision populations.Our protocol was registered in the PROSPERO database(reg.No.CRD42021255021).Eligible studies were defined as those on a population of low vision patients wherein the prevalence of CBS was evaluated(without any further restriction on the method for diagnosis of CBS).No restriction was enforced on study design,but we expected observational cross-sectional studies due to the nature of our research question.Two authors independently extracted data and evaluated risk of bias of individual studies using the Agency for Healthcare Research and Quality checklist for cross-sectional studies.Studies underwent qualitative review in the text and quantitatively in a prevalence meta-analysis using the random-effects model.Sensitivity analysis was made to evaluate the robustness of the summary estimate.Results:We identified 11 studies,which summarized data on 4,521 individuals with visual impairment.Diagnosis of CBS was based on screening questions or interviews,which in positive cases often was explored in more detail with follow-up questions or interviews.Most studies either had normal mental state as a participant eligibility criterion or as a part of the diagnosis of CBS.The pooled prevalence of CBS in low vision patients aged≥40 years was 19.7%(95%CI:13.8%to 26.4%).The sensitivity analysis showed certain robustness in the summary prevalence estimate wherein prevalence estimates ranged from 16.9%to 22.5%.Conclusions:CBS is a prevalent condition in patients with low vision at a rate of approximately one in five patients.Considering that an estimated 239 million individuals have moderate visual impairment or worse,we estimate a global number of patients with CBS at approximately 47.2 million.

A Low Complexity VCS Method for PAPR Reduction in Multicarrier Code Division Multiple Access

This paper investigates a peak to average power ratio （PAPR） reduction method in multicarrier code division multiple access （MC-CDMA） system. Variable code sets （VCS）, a spreading codes selection scheme, can improve the PAPR property of the MC-CDMA signals, but this technique requires an exhaustive search over the combinations of spreading code sets. It is observed that when the number of active users increases, the search complexity will increase exponentially. Based on this fact, we propose a low complexity VCS （LC-VCS） method to reduce the computational complexity. The basic idea of LC-VCS is to derive new signals using the relationship between candidature signals. Simulation results show that the proposed approach can reduce PAPR with lower comtational pucomplexity. In addition, it can be blindly received without any side information.

A Solution for Scalable Routing in Depth Divisions-Based DUSNs via Adding a Scalable Parameter to Control Depth Clusters: Creating an Energy Efficient and Low Delay NI-Independent Communication Protocol

Due to effectiveness of network layer on general performance of networks, designing routing protocols is very important for lifetime and traffic efficiency in wireless sensor networks. So in this paper, we are going to represent an efficient and scalable version of depth-based routing (DBR) protocol that is limited by depth divisions-policy. In fact the new version is a network information independent routing protocol for acoustic communications. Proposed method by use of depth clustering is able to reduce consumed energy and end-to-end delay in dense underwater sensor networks (DUSNs) and this issue is proved by simulation.

AB030.Usability of ArtontheBrain:A visual-arts based mobile health solution to promote quality of life in older adults with low vision due to age-related macular degeneration

Background:Taking part in productive and enjoyable recreational activities has been shown improve quality of life for people of all ages and capabilities.However,vision loss can have a significant impact on participation in important leisure activities.This is especially the case for the elderly,whose lowered mobility is further impacted by vision loss.Technology can offer solutions to bridging some barriers caused by these deficits by bringing leisure activities to the user in the form of mobile applications.As such,the purpose of the present study was to evaluate the accessibility and usability of the ArtOnTheBrain application,a visual art based mobile health solution to promote brain health and well-being,by older adults with low vision due to age-related macular degeneration(AMD).Methods:There were a total of 16 participants(age range,65-93 years,M=79,10 males).All had a diagnosis of AMD with visual acuities in the better eye between 20/60 and 20/200.Additionally,all participants had accessed rehabilitation services and most had experience using a computer at home.Using an Apple iPad Air(2013),they were asked to interact with the ArtOnTheBrain website’s Learn(e.g.,Listen to artwork description)and Play(e.g.,complete a word-search game)features with either the Safari or Google Chrome Internet apps.Using the Concurrent Think Aloud method,participants were asked to continuously comment on their activities and experiences with the app and verbalize their internal monologue while being audio and video recorded.These recordings were later transcribed verbatim and analysed using qualitative description and thematic analysis.Results:Participants’behaviours and verbal feedback were divided based on whether they presented as barriers or facilitators.Beginning with barriers,these were mostly related to the accessibility of the visual aspects of the applications interface(i.e.,contrast and font size),whereby participants requested additional control over the magnification options,both for text as well as images of the artwork.The main facilitator was the audio option built into the Learn tab,which allowed participants to listen to the artwork descriptions.Facilitators also included the aesthetics of the app,the perceived boost in confidence in interacting with technology,and the educational and leisure benefits.Conclusions:Older adults with low vision are faced with a decreased ability to engage in leisure activities.The development of technologies aimed at increasing the accessibility of leisure activities for these individuals is an important step in increasing their quality of life.As such,despite some of the accessibility challenges,the majority of participants viewed ArtontheBrain positively.Identifying the barriers and facilitators to its use is an important step in the development of this application in order to optimize its accessibility for older adults with low vision.Future work to be done with this application will be to evaluate the cognitive impact of ArtontheBrain on low vision users.

An NMOS output-capacitorless low-dropout regulator with dynamic-strength event-driven charge pump

In this paper,an NMOS output-capacitorless low-dropout regulator(OCL-LDO)featuring dual-loop regulation has been proposed,achieving fast transient response with low power consumption.An event-driven charge pump(CP)loop with the dynamic strength control(DSC),is proposed in this paper,which overcomes trade-offs inherent in conventional structures.The presented design addresses and resolves the large signal stability issue,which has been previously overlooked in the event-driven charge pump structure.This breakthrough allows for the full exploitation of the charge-pump structure's poten-tial,particularly in enhancing transient recovery.Moreover,a dynamic error amplifier is utilized to attain precise regulation of the steady-state output voltage,leading to favorable static characteristics.A prototype chip has been fabricated in 65 nm CMOS technology.The measurement results show that the proposed OCL-LDO achieves a 410 nA low quiescent current(IQ)and can recover within 30 ns under 200 mA/10 ns loading change.

Clinical usefulness of the baby vision test in young children and its correlation with the Snellen chart

AIM:To investigate the efficacy of a new visual acuity(VA)screening method,the baby vision test for young children.METHODS:A total 105 eyes of 65 children aged 2-8y were included in the study.Acuity testing was conducted using a standardized recognition acuity chart(Snellen visual chart:at 3 m)and the baby vision model assessment.The baby vision device includes a screen,a near infrared camera and a computer.Children were seated at a measured distance of 33-40 cm from a display for testing.VA was estimated according to the highest resolution the children could follow.Decimal VA data were converted to logarithm of the minimum angle of resolution(logMAR)for statistical analysis.The VA results for each child were recorded and analyzed for consistency.RESULTS:The mean VA measured using the Snellen visual chart was 0.62±0.32,and that assessed using the baby vision test was 0.66±0.27.The 95%limit of agreement was-0.609 to 0.695,with 95.2%(100/105)plots within the 95%limits of agreement.VA values of the baby vision test were significantly correlated with those of the Snellen chart(R=0.274,P=0.005).CONCLUSION:The baby vision test can be used as a relatively reliable method for estimating VA in young children.This new acuity assessment might be a valid predictor of optotype-measured acuity later in preverbal children.

SlowFast架构下景区异常行为识别算法及预警研究

针对当前古建筑场景下人员异常行为识别相关实例缺乏、数据集少、古建筑级别低、质量次,导致人员异常行为识别准确率低等问题,该文在古建筑景区背景下自行拍摄了多组视频,从中挑选构建了人员异常行为动作的5033段视频数据集:具有明确的典型古建筑背景;具有多人场景下暴恐打架斗殴、刻划、刻画以及存在火灾风险的人员异常行为等特征,并对每个视频进行了注释。该文首次于SlowFast网络框架中成功引入信号时域特征活动性、移动性参数,对构建的数据集进行高阶时序特征建模、增加分类算子。在人员异常行为识别任务中,模型的Top1准确率达到93.54%,而平均准确率达到96.30%,在SlowFast模型中引入活动性、移动性算子后,模型识别的准确率提升了0.87%。与几种常见架构的算法相比,该文所提出的方法存在一定的优势。