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.

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.

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.

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.

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...

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.

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...

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.

Cella vision DM96血细胞形态自动成像仪在低值血小板计数中的应用

目的探讨Cella vision DM96血细胞形态成像仪在计数低值血小板中的应用价值。方法采用SYSMEX XE-2100全自动血细胞分析仪的电阻抗法对血常规标本520例进行测定,随机选择血小板计数在<100×109/L范围内的76例标本,对所选择低值血小板的标本用SYSMEX-XE2100血细胞分析仪进行光学法计数血小板,再用Sysmenx sp-1000i自动化涂片染色仪对所选标本涂片染色,然后用Cella vision DM96血细胞形态自动成像仪(简称DM96)对标本进行血小板计数,用相关性回归统计学方法分析DM96对低值血小板计数的准确性。结果 SYSMEX XE-2100全自动血细胞分析仪电阻抗法和光学法相关性良好(R2=0.9087),光学法计数普遍要比电阻抗法计数高。DM96和血细胞分析仪对血小板计数的两种方法有较好的相关性(电阻抗法和光学法的R2分别为0.8395和0.8252)。结论用SYSMEX-XE2100血细胞分析仪对低值血小板计数检测后,对于有大血小板存在和血小板聚集的标本,CellavisionDM96的方法更能把血小板形态和分布以数码图片的方式形象的显示出来,结果更加准确,有利于结果的判断。

Reversibility of visual field defects through induction of brain plasticity: vision restoration, recovery and rehabilitation using alternating current stimulation

For decades visual field defects were considered irreversible because it was thought that in the visual system the regeneration potential of the neuronal tissues is low.Nevertheless,there is always some potential for partial recovery of the visual field defect that can be achieved through induction of neuroplasticity.Neuroplasticity refers to the ability of the brain to change its own functional architecture by modulating synaptic efficacy.It is maintained throughout life and just as neurological rehabilitation can improve motor coordination,visual field defects in glaucoma,diabetic retinopathy or optic neuropathy can be improved by inducing neuroplasticity.In ophthalmology many new treatment paradigms have been tested that can induce neuroplastic changes,including non-invasive alternating current stimulation.Treatment with alternating current stimulation(e.g.,30 minutes,daily for 10 days using transorbital electrodes and^10 Hz)activates the entire retina and parts of the brain.Electroencephalography and functional magnetic resonance imaging studies revealed local activation of the visual cortex,global reorganization of functional brain networks,and enhanced blood flow,which together activate neurons and their networks.The future of low vision is optimistic because vision loss is indeed,partially reversible.

Research on Night Vision System Based on Range-Gated Imaging

A design of low-light-level night vision system is described,which can image objects selectively in the specific space. The system can selectively image some objects in specific distances,meanwhile ignore those shelters on the way of observation by combining an intensifying charge coupled device(ICCD) with a near infrared laser assisted in vision,whose operation wavelength matches with the photocathode of the image tube,and adopting the gated mode and adjustable time-delay. A semiconductor laser diode of 100 W in peak power is chosen for illumination. The laser and the image tube operate in 150 ns pulse width and 2 kHz repeat frequency. Some images of different objects at the different distances within 100 m can be obtained clearly,and even behind a grove by using a sampling circuit and a delay control device at 100 W in peak power of semiconductor laser diode,150 ns in pulse width of laser and image tube,2 kHz in repeat frequency.

The Etiology of Vision Impairment in Target Population

Purpose: research the etiology of vision impairment in target persons over 45 years old in Doumen county , Guangdong province.Methods: Depending on the prevalences of the blindness among the person aged over 50 years, the theoretic sample rate is 1 000/4 8733×100%=2. 05%. The 8 districts were divided into 3 parts according to the local economic situation and the proportion of the population in the areas. In fact, the sampling rate is 932/ 10055 = 88.34%.Results:W’e found that impairment 【0. 3 accounted for 10. 94%. The prevalence of bilateral blindness and low vision was 1. 61% and 3. 22%, respectively. Both prevalences of blindness and low vision were increased with age. The leading cuase of blindness was cataract (45. 2%). The second was corneal opacity (16. 7% ). Prevalentces of the low vision and the blindness were higher in females than in males (P【0. 005).Conclusions: Curable and preventable diseases were the leading cause for the blindness (70%). Prevalences of blindness and the low vision

Enhance Egocentric Grasp Recognition Based Flex Sensor Under Low Illumination

Egocentric recognition is exciting computer vision research by acquiring images and video from the first-person overview.However,an image becomes noisy and dark under low illumination conditions,making subsequent hand detection tasks difficult.Thus,image enhancement is necessary to make buried detail more visible.This article addresses the challenge of egocentric hand grasp recognition in low light conditions by utilizing the flex sensor and image enhancement algorithm based on adaptive gamma correction with weighting distribution.Initially,a flex sensor is installed to the thumb for object manipulation.The thumb placement that holds in a different position on the object of each grasp affects the voltage changing of the flex sensor circuit.The average voltages are used to configure the weighting parameter to improve images in the image enhancement stage.Moreover,the contrast and gamma function are used to adjust varies the low light condition.These grasp images are then separated to be training and testing with pretrained deep neural networks as the feature extractor in YOLOv2 detection network for the grasp recognition system.The proposed of using a flex sensor significantly improves the grasp recognition rate in low light conditions.

AB034. Knowledge and understanding of eye disease among older adults with vision impairment

Background:By 2026,projections indicate that 1/5 Canadians will be over the age of 65.This shift in demographics will be accompanied by an increase in age-related eye disease.Survey studies have reported vision loss as a major medical concern among older adults,but there is little information on older adults’awareness and knowledge of age-related eye diseases.A lack of knowledge can lead to missed or delayed treatment and/or lifestyle modification.This study aims to assess the knowledge and understanding older adults have of their own eye disease and its prognosis.Methods:Participants over the age of 50 with a visual impairment were recruited from the MAB-Mackay Rehabilitation Centre,the Low Vision Self-Help Association(LVSHA)of the West Island and through word of mouth.Visual acuity and contrast sensitivity were measured using the ETDRS charts and Mars Charts,respectively.Optical coherence tomography(OCT)/scanning laser ophthalmoscopy was used to take cross-sectional images of participant retinas.Participants were asked to name their visual diagnoses and describe them in their own words.Participant diagnoses were compared to diagnoses determined by an optometrist or ophthalmologist.Results:To date,this study has recruited 26 participants(7M,19F)over the age of 50 years(range,51-95 years).Many participants(73%)were able to name their visual diagnoses,articulate their symptoms,and discuss their treatment and prognosis.The majority of these individuals(67%)were clients of the MAB-Mackay or participants in the LVSHA.Of the 27%(4M,4F)who were unclear or had misunderstood their diagnoses,half were participants in a low vision support group,but they had multiple visual diagnoses and it was the congenital or trauma-related visual impairments acquired before joining the MAB-Mackay or LVSHA that remained unclear.The other 4 individuals who misunderstood their diagnoses were not involved with any low vision or rehabilitation organizations.Conclusions:Visual impairment is sometimes dismissed as part of aging.A lack of awareness and knowledge can lead to missed or delayed treatment and/or lifestyle modifications.The preliminary results of this study demonstrate the important role organizations like the MAB-Mackay and LVSHA play in education and adaptation to low vision for older adults.Individuals with a better understanding of their own diagnoses are more likely to follow through with doctor-recommendations and have successful treatment or slowed progression.

AB100.Screening for vision and hearing loss in patients with dementia:recommendations from interviews with sensory experts

Background:Dementia is a syndrome that affects a person’s ability to understand and express information.The higher prevalence of vision and/or hearing losses among persons with dementia in long-term care(LTC)facilities interferes with the ability of nurses to provide optimal care because communication is compromised.Therefore,the detection and screening for sensory impairment is of the utmost importance in LTC facilities;however,there is currently no agreement among nursing professionals on how to best identify such losses for the purpose of further referral,and the need for a validated screening measure suitable for nurses in LTC facilities is clear.The present project aims to close this gap by investigating the screening recommendations of vision-and hearing-care professionals working with clients affected by dementia.Methods:Eleven experts in audiology,optometry,deafblindness,and technology participated in individual semi-structured interviews on the topic of tools and strategies that can be used to screen individuals with dementia for sensory loss.Interview transcripts were coded by two evaluators using verbal agreement and consensus building.Results:Three main themes emerged from the interviews with experts:barriers,facilitators,and strategies.Barriers to sensory screening were often mentioned,particularly impaired communication and lack of staff cooperation.Facilitators consisted uniquely of people,such as family members,intervenors,and nurses.Strategies for sensory screening in this population consisted of improving communication through repetition and encouragements;considerations based on familiarity;and inferring an impairment on the basis of patient behaviour.Few of our interviewees were knowledgeable on the topic of screening apps.Conclusions:Our findings,to be integrated with a similar environmental scan conducted among LTC nurses,can inform the administration of sensory impairment screening tests among a population with dementia in order to optimize care.

基于计算机视觉的腰背痛患者痧象图片处理和分析研究

目的提出痧象图片处理和分析的思路和方法,为痧象数字化研究提供参考。方法以计算机视觉技术为基础,以腰背痛患者背部痧象处理和分析为目标,提出痧象图片预处理、特征提取和筛选、痧象分析等系列方法,并进行实验验证。结果痧象预处理方法能够实现原始图像颜色校正和背部区域精准分割;特征提取方法提取了腰背痛患者94个痧象颜色和纹理特征,筛选得到20个关键特征;痧象分析方法能够找到与不同证候相关的关键特征。结论利用计算机视觉方法能够较好地完成痧象图片的预处理、特征识别和提取、痧象分析和理解,可以为痧象数字化和客观化研究提供支撑。

近视针刺法联合指针疗法防控儿童低中度近视的疗效观察

目的 探讨近视针刺法联合指针疗法防控儿童低中度近视临床疗效。方法 选取2020年1月—2022年10月期间首都医科大学附属北京同仁医院就诊的低中度近视儿童86例,按随机数字表方法分为对照组和观察组,每组各43例。对照组给予配镜治疗,观察组在对照组基础上予近视针刺法联合指针疗法。治疗1个月后,观察两组患儿治疗前后临床疗效,治疗前后中医证候评分,裸眼视力,屈光度,眼轴长度,调节幅度。结果 治疗后两组患儿观察组临床总有效率93.02%(40/43)明显高于对照组74.42%(32/43),差异有统计学意义(P<0.05)。治疗后两组患儿中医证候评分均较治疗前降低,差异有统计学意义(P<0.05);且观察组中医证候评分明显低于对照组,差异有统计学意义(P<0.05)。治疗后两组患儿裸眼视力及屈光度均较治疗前升高,差异有统计学意义(P<0.05);且观察组裸眼视力及屈光度均明显高于对照组,差异有统计学意义(P<0.05)。治疗后两组患儿眼轴长度及调节幅度均较治疗前升高,差异有统计学意义(P<0.05);且观察组眼轴增长幅度低于对照组,调节幅度高于对照组,差异有统计学意义(P<0.05)。结论 近视针刺法联合指针疗法防控儿童低中度近视临床疗效显著。