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Ophthalmology Oct 2018Presbyopia prevalence and spectacle-correction coverage were estimated by systematic review and meta-analysis of epidemiologic evidence, then modeled to expand to... (Meta-Analysis)
Meta-Analysis
TOPIC
Presbyopia prevalence and spectacle-correction coverage were estimated by systematic review and meta-analysis of epidemiologic evidence, then modeled to expand to country, region, and global estimates.
CLINICAL RELEVANCE
Understanding presbyopia epidemiologic factors and correction coverage is critical to overcoming the burden of vision impairment (VI) from uncorrected presbyopia.
METHODS
We performed systematic reviews of presbyopia prevalence and spectacle-correction coverage. Accepted presbyopia prevalence data were gathered into 5-year age groups from 0 to 90 years or older and meta-analyzed within World Health Organization global burden of disease regions. We developed a model based on amplitude of accommodation adjusted for myopia rates to match the regionally meta-analyzed presbyopia prevalence. Presbyopia spectacle-correction coverage was analyzed against country-level variables from the year of data collection; variation in correction coverage was described best by a model based on the Human Development Index, Gini coefficient, and health expenditure, with adjustments for age and urbanization. We used the models to estimate presbyopia prevalence and spectacle-correction coverage in each age group in urban and rural areas of every country in the world, and combined with population data to estimate the number of people with near VI.
RESULTS
We estimate there were 1.8 billion people (prevalence, 25%; 95% confidence interval [CI], 1.7-2.0 billion [23%-27%]) globally with presbyopia in 2015, 826 million (95% CI, 686-960 million) of whom had near VI because they had no, or inadequate, vision correction. Global unmet need for presbyopia correction in 2015 is estimated to be 45% (95% CI, 41%-49%). People with presbyopia are more likely to have adequate optical correction if they live in an urban area of a more developed country with higher health expenditure and lower inequality.
CONCLUSIONS
There is a significant burden of VI from uncorrected presbyopia, with the greatest burden in rural areas of low-resource countries.
Topics: Eyeglasses; Global Health; Humans; Presbyopia; Prevalence; Vision Disorders; Visual Acuity; Visually Impaired Persons
PubMed: 29753495
DOI: 10.1016/j.ophtha.2018.04.013 -
Psychiatria Polska Apr 2020Anxiety and anxiety disorders among people with visual impairment are more frequent than in the general population. It is estimated that . of people with visual... (Review)
Review
Anxiety and anxiety disorders among people with visual impairment are more frequent than in the general population. It is estimated that . of people with visual impairment face depression and/or anxiety, whereas 4-6% of people are diagnosed with anxiety disorders. The purpose of this paper is analyzing the occurrence of anxiety in people with visual impairment based on current information. Literature review indicates that people with visual impairment experience the common, as well as the more specific, often chronic anxiety symptoms. Despite the significance of the foregoing phenomenon and its negative consequences, literature does not explain its causes, specify the problem, and most importantly, does not provide recommendations for preventing the occurrence of anxiety in the foregoing group of people. In order to understand the nature of anxiety, it is important to learn more about its causes and consequences for health,both biopsychosocial and spiritual wellbeing. In people with visual impairment this may depend on particular conditions which these people face every day, therefore the concept of anxiety in this group of people requires a separate consideration.
Topics: Anxiety; Attitude to Health; Comorbidity; Female; Humans; Male; Quality of Life; Vision Disorders; Visually Impaired Persons
PubMed: 32772060
DOI: 10.12740/PP/OnlineFirst/85408 -
Journal of Pediatric Ophthalmology and... 2022
Topics: Child; Humans; Sleep Wake Disorders; Vision Disorders; Visually Impaired Persons
PubMed: 35343821
DOI: 10.3928/01913913-20220202-01 -
Scientific Reports May 2023According to World Health Organization (WHO), currently, 2.2 billion people are living with visual impairment worldwide, of which almost half could have been prevented....
According to World Health Organization (WHO), currently, 2.2 billion people are living with visual impairment worldwide, of which almost half could have been prevented. There are both modifiable and unmodifiable factors leading to visual disability and, ultimately, blindness. Several population-based studies in different parts of Iran have tried to determine these factors concerning their specific population and environment-related characteristics. AZAR Eye and Vision cohort is the second-largest cohort study in the whole country. AZAR Eye and Vision cohort is the ophthalmologic branch of AZAR cohort which is the largest eye cohort study in the country, which is trying to determine the prevalence and incidence of visual impairment, blindness, and other major ophthalmologic conditions and their associated risk factors in East Azerbaijan province located in Iran, a middle eastern country. A recently emerging phenomenon is the drying of the ultra-salty lake of Urmia located in the West Azerbaijan province which is a direct neighbor of our studied population and has caused recurrent salt storms in the immediate near areas. This phenomenon could adversely affect visual health via different conditions which our study will elucidate. The enrollment phase took place between 2014 and 2017 and 11,208 participants were enrolled out of 15,000 participants in the primary cohort. The resurvey phase will begin five years after the enrollment phase. In this phase, 30% of the participants are randomly selected to be reexamined and complete questionnaires. The participants showing any issues such as diabetes and being a glaucoma suspect will be included in the resurvey phase, too. Data categories gathered include demographics, lifestyle factors, past medical and drug histories, and a diet quality and quantity questionnaire including 130 edible items. Urine, hair, nail, and 25-ml blood samples, were collected from the participants. Then they were referred to an optometrist to complete an ophthalmologic questionnaire and undergo eye examination and lensometry. Then they underwent slit-lamp examinations and pictures were taken of the lens and fundus. People with suspected visual impairment were referred to an ophthalmology clinic. The data are processed and a four-level quality check is performed on each block. The most common visual impairment is cataracts. This study's most important aim is to evaluate the effect of local environmental and ethnic factors on eye diseases in this specific population.
Topics: Humans; Visually Impaired Persons; Cohort Studies; Visual Acuity; Blindness; Vision, Low; Eye Diseases; Ocular Hypertension; Prevalence; Vision Disorders
PubMed: 37198199
DOI: 10.1038/s41598-023-30212-y -
Wiley Interdisciplinary Reviews.... 2016Spatial navigation in the absence of vision has been investigated from a variety of perspectives and disciplines. These different approaches have progressed our... (Review)
Review
Spatial navigation in the absence of vision has been investigated from a variety of perspectives and disciplines. These different approaches have progressed our understanding of spatial knowledge acquisition by blind individuals, including their abilities, strategies, and corresponding mental representations. In this review, we propose a framework for investigating differences in spatial knowledge acquisition by blind and sighted people consisting of three longitudinal models (i.e., convergent, cumulative, and persistent). Recent advances in neuroscience and technological devices have provided novel insights into the different neural mechanisms underlying spatial navigation by blind and sighted people and the potential for functional reorganization. Despite these advances, there is still a lack of consensus regarding the extent to which locomotion and wayfinding depend on amodal spatial representations. This challenge largely stems from methodological limitations such as heterogeneity in the blind population and terminological ambiguity related to the concept of cognitive maps. Coupled with an over-reliance on potential technological solutions, the field has diffused into theoretical and applied branches that do not always communicate. Here, we review research on navigation by congenitally blind individuals with an emphasis on behavioral and neuroscientific evidence, as well as the potential of technological assistance. Throughout the article, we emphasize the need to disentangle strategy choice and performance when discussing the navigation abilities of the blind population. For further resources related to this article, please visit the WIREs website.
Topics: Blindness; Brain; Humans; Space Perception; Spatial Learning; Spatial Navigation
PubMed: 26683114
DOI: 10.1002/wcs.1375 -
Journal of Global Health Nov 2023Retinal disorders cause substantial visual burden globally. Accurate estimates of the vision loss due to retinal diseases are pivotal to inform optimal eye health care...
BACKGROUND
Retinal disorders cause substantial visual burden globally. Accurate estimates of the vision loss due to retinal diseases are pivotal to inform optimal eye health care planning and allocation of medical resources. The purpose of this study is to describe the proportion of visual impairment and blindness caused by major retinal diseases in China.
METHODS
A nationwide register-based study of vitreoretinal disease covering all 31 provinces (51 treating centres) of mainland China. A total of 28 320 adults diagnosed with retinal diseases were included. Participants underwent standardised ocular examinations, which included best-corrected visual acuity (BCVA), dilated-fundus assessments, and optical coherence tomography. Visual impairment and blindness are defined using BCVA according to the World Health Organization (WHO) (visual impairment: <20/63-≥20/400; blindness: <20/400) and the United States (visual impairment: <20/40-≥20/200; blindness: <20/200) definitions. The risk factors of vision loss were explored by logistic regression analyses.
RESULTS
Based on the WHO definitions, the proportions for unilateral visual impairment and blindness were 46% and 18%, respectively, whereas those for bilateral visual impairment and blindness were 31% and 3.3%, respectively. Diabetic retinopathy (DR) accounts for the largest proportion of patients with visual impairment (unilateral visual impairment: 32%, bilateral visual impairment: 60%) and blindness (unilateral blindness: 35%; bilateral blindness: 64%). Other retinal diseases that contributed significantly to vision loss included age-related macular degeneration, myopic maculopathy, retinal vein occlusion, and rhegmatogenous retinal detachment and other macular diseases. Women (bilateral vision loss: P = 0.011), aged patients (unilateral vision loss: 45-64 years: P < 0.001, ≥65 years: P < 0.001; bilateral vision loss: 45-64 years: P = 0.003, ≥65 years: P < 0.001 (reference: 18-44 years)) and those from Midwest China (unilateral and bilateral vision loss: both P < 0.001) were more likely to suffer from vision loss.
CONCLUSIONS
Retinal disorders cause substantial visual burden among patients with retinal diseases in China. DR, the predominant retinal disease, is accountable for the most prevalent visual disabilities. Better control of diabetes and scaled-up screenings are warranted to prevent DR. Specific attention should be paid to women, aged patients, and less developed regions.
Topics: Adult; Humans; Female; Aged; Visually Impaired Persons; Visual Acuity; Blindness; Vision, Low; Vision Disorders; Retinal Diseases; Macular Degeneration; Diabetic Retinopathy; Prevalence
PubMed: 37921040
DOI: 10.7189/jogh.13.04126 -
Indian Journal of Ophthalmology Aug 2021To determine the causes of severe visual impairment and blindness in children in schools for the blind in the city of Bangalore, Karnataka and to determine the error of... (Review)
Review
PURPOSE
To determine the causes of severe visual impairment and blindness in children in schools for the blind in the city of Bangalore, Karnataka and to determine the error of inclusion and exclusion from these schools.
METHODS
This was a cross-sectional study. Children in four schools for the blind were subjected to a detailed ophthalmic evaluation. The World Health Organization Program for Prevention of Blindness low-vision form was used to collect data. To know the educational background of children with visual disability of 40% or more (best-corrected visual acuity of ≤6/24 in the better eye), not in schools for the blind, we collected data by telephonic conversation after procuring their phone numbers from our low-vision clinic.
RESULTS
One-hundred-seventy-eight children were examined. The major site of anomaly causing blindness in 31% of children was optic nerve, followed by retina (24%), cornea (23%), and whole globe (22%). Avoidable blindness was 35.42%. Thirteen percent of the children with no visual disability were incorrectly enrolled in blind schools. We were able to contact 92 children with a visual disability of ≥40%. Seventy-eight children (84.78%) attended regular schools; these schools were bereft of a specially trained teacher to look after the needs of the blind.
CONCLUSION
Avoidable blindness is still a cause for concern. Children should undergo eye-examination before being enrolled in schools for the blind to avoid errors of inclusion. Though integrated education for children with vision disability is a good approach, it requires teachers trained in teaching skills particular to blindness. Education for the visually impaired in India needs a major revision.
Topics: Blindness; Child; Cross-Sectional Studies; Humans; India; Schools; Vision, Low; Visually Impaired Persons
PubMed: 34304171
DOI: 10.4103/ijo.IJO_3725_20 -
Ophthalmology Aug 2023We provide global estimates of the prevalence of corneal blindness and vision impairment in adults 40 years of age and older and examine the burden by age, sex, and... (Meta-Analysis)
Meta-Analysis Review
TOPIC
We provide global estimates of the prevalence of corneal blindness and vision impairment in adults 40 years of age and older and examine the burden by age, sex, and geographic region from 1984 through 2020.
CLINICAL RELEVANCE
Corneal opacities (COs) are among the top 5 causes of blindness worldwide, yet the global prevalence, regional differences, and risk factors are unclear.
METHODS
Abstracted data from the published literature and surveys were obtained from the Global Burden of Disease Vision Loss Expert Group. We supplemented this by an independent systematic literature search of several databases. Studies that provided CO vision impairment data based on population-based surveys for those 40 years of age or older were included, for a total of 244. For each of the 4 outcomes of blindness and moderate to severe vision impairment (MSVI) caused by trachomatous and nontrachomatous CO (NTCO), time trends and differences in prevalence by region, age, and sex were evaluated using a Poisson log-linear model with a generalized estimating equation method. Age-standardized estimates of global prevalence of blindness and MSVI were calculated using the 2015 United Nations standard populations.
RESULTS
The global prevalence of blindness resulting from NTCO in those 40 years and older was 0.081% (95% confidence interval [CI], 0.049%-0.315%); that of MSVI was 0.130% (95% CI, 0.087%-0.372%). A significant increase with age was found (prevalence rate ratio, 2.15; 95% CI, 1.99-2.32). Latin America and Europe showed the lowest rates, with 2- to 8-fold higher rates of blindness or MSVI in other regions. The global prevalence of blindness resulting from trachomatous CO in those 50 years and older was 0.0094% (95% CI, 0%-0.0693%); that from MSVI was 0.012% (95% CI, 0%-0.0761%). Blindness resulting from trachomatous CO and MSVI increased with age and female sex, and rates were significantly higher in the African regions. A decrease in trachomatous blindness rates over time was found (prevalence rate ratio, 0.91; 95% CI, 0.86-0.96).
DISCUSSION
An estimated 5.5 million people worldwide are bilaterally blind or have MSVI resulting from CO, with an additional 6.2 million unilaterally blind. Blindness resulting from trachomatous CO is declining over time, likely because of the massive scaleup of the global trachoma elimination program and overall socioeconomic development.
FINANCIAL DISCLOSURE(S)
The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Topics: Adult; Humans; Female; Blindness; Vision Disorders; Visually Impaired Persons; Trachoma; Corneal Opacity; Prevalence
PubMed: 36963570
DOI: 10.1016/j.ophtha.2023.03.012 -
Sensors (Basel, Switzerland) Jan 2023Laser sensing and vision sensing smart canes can improve the convenience of travel for the visually impaired, but for the present, most of the system functions of laser... (Review)
Review
Laser sensing and vision sensing smart canes can improve the convenience of travel for the visually impaired, but for the present, most of the system functions of laser sensing and vision sensing smart canes are still defective. Guide equipment and smart blind canes are introduced and classified first, and the smart blind canes based on vision sensing, laser sensing and laser vision sensing are investigated, respectively, and the research status of laser vision sensing smart blind canes is sorted out. The advantages and disadvantages of various laser vision sensing smart blind canes are summarized, especially the research development of laser vision fusion as the core of new smart canes. The future development prospects of laser vision sensing smart blind cane are overviewed, to boost the development of laser vision sensing smart blind cane, to provide safe and efficient travel guarantee for the visually impaired.
Topics: Humans; Canes; Equipment Design; Blindness; Visually Impaired Persons
PubMed: 36679665
DOI: 10.3390/s23020869 -
Sensors (Basel, Switzerland) Oct 2022The visually impaired suffer greatly while moving from one place to another. They face challenges in going outdoors and in protecting themselves from moving and... (Review)
Review
The visually impaired suffer greatly while moving from one place to another. They face challenges in going outdoors and in protecting themselves from moving and stationary objects, and they also lack confidence due to restricted mobility. Due to the recent rapid rise in the number of visually impaired persons, the development of assistive devices has emerged as a significant research field. This review study introduces several techniques to help the visually impaired with their mobility and presents the state-of-the-art of recent assistive technologies that facilitate their everyday life. It also analyses comprehensive multiple mobility assistive technologies for indoor and outdoor environments and describes the different location and feedback methods for the visually impaired using assistive tools based on recent technologies. The navigation tools used for the visually impaired are discussed in detail in subsequent sections. Finally, a detailed analysis of various methods is also carried out, with future recommendations.
Topics: Humans; Visually Impaired Persons; Self-Help Devices; Technology
PubMed: 36298237
DOI: 10.3390/s22207888