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The Lancet. Global Health Feb 2021Many causes of vision impairment can be prevented or treated. With an ageing global population, the demands for eye health services are increasing. We estimated the... (Meta-Analysis)
Meta-Analysis
Causes of blindness and vision impairment in 2020 and trends over 30 years, and prevalence of avoidable blindness in relation to VISION 2020: the Right to Sight: an analysis for the Global Burden of Disease Study.
BACKGROUND
Many causes of vision impairment can be prevented or treated. With an ageing global population, the demands for eye health services are increasing. We estimated the prevalence and relative contribution of avoidable causes of blindness and vision impairment globally from 1990 to 2020. We aimed to compare the results with the World Health Assembly Global Action Plan (WHA GAP) target of a 25% global reduction from 2010 to 2019 in avoidable vision impairment, defined as cataract and undercorrected refractive error.
METHODS
We did a systematic review and meta-analysis of population-based surveys of eye disease from January, 1980, to October, 2018. We fitted hierarchical models to estimate prevalence (with 95% uncertainty intervals [UIs]) of moderate and severe vision impairment (MSVI; presenting visual acuity from <6/18 to 3/60) and blindness (<3/60 or less than 10° visual field around central fixation) by cause, age, region, and year. Because of data sparsity at younger ages, our analysis focused on adults aged 50 years and older.
FINDINGS
Global crude prevalence of avoidable vision impairment and blindness in adults aged 50 years and older did not change between 2010 and 2019 (percentage change -0·2% [95% UI -1·5 to 1·0]; 2019 prevalence 9·58 cases per 1000 people [95% IU 8·51 to 10·8], 2010 prevalence 96·0 cases per 1000 people [86·0 to 107·0]). Age-standardised prevalence of avoidable blindness decreased by -15·4% [-16·8 to -14·3], while avoidable MSVI showed no change (0·5% [-0·8 to 1·6]). However, the number of cases increased for both avoidable blindness (10·8% [8·9 to 12·4]) and MSVI (31·5% [30·0 to 33·1]). The leading global causes of blindness in those aged 50 years and older in 2020 were cataract (15·2 million cases [9% IU 12·7-18·0]), followed by glaucoma (3·6 million cases [2·8-4·4]), undercorrected refractive error (2·3 million cases [1·8-2·8]), age-related macular degeneration (1·8 million cases [1·3-2·4]), and diabetic retinopathy (0·86 million cases [0·59-1·23]). Leading causes of MSVI were undercorrected refractive error (86·1 million cases [74·2-101·0]) and cataract (78·8 million cases [67·2-91·4]).
INTERPRETATION
Results suggest eye care services contributed to the observed reduction of age-standardised rates of avoidable blindness but not of MSVI, and that the target in an ageing global population was not reached.
FUNDING
Brien Holden Vision Institute, Fondation Théa, The Fred Hollows Foundation, Bill & Melinda Gates Foundation, Lions Clubs International Foundation, Sightsavers International, and University of Heidelberg.
Topics: Aged; Aged, 80 and over; Blindness; Cataract; Eye Diseases; Female; Glaucoma; Global Burden of Disease; Global Health; Humans; Macular Degeneration; Male; Middle Aged; Refractive Errors; Vision Disorders; Vision, Low; Visual Acuity
PubMed: 33275949
DOI: 10.1016/S2214-109X(20)30489-7 -
The Medical Clinics of North America May 2021Age-related macular degeneration (AMD) is a leading cause of blindness. The main risk factor is advancing age, with the severity of vision loss ranging from mild to... (Review)
Review
Age-related macular degeneration (AMD) is a leading cause of blindness. The main risk factor is advancing age, with the severity of vision loss ranging from mild to severe. There is a 25% risk of early AMD and 8% risk of late AMD in patients over the age of 75, with the number of cases expected to increase because of the aging population. Diagnosis of the disease requires a dilated fundus examination. Physicians should be aware of the symptoms, risk factors, and treatment options for AMD to refer appropriately for ophthalmologic evaluation. Early detection can be helpful to prevent disease progression.
Topics: Blindness; Humans; Macular Degeneration; Risk Factors; Sensory Aids; Vision, Low
PubMed: 33926642
DOI: 10.1016/j.mcna.2021.01.003 -
The Lancet. Global Health Feb 2021To contribute to the WHO initiative, VISION 2020: The Right to Sight, an assessment of global vision impairment in 2020 and temporal change is needed. We aimed to... (Meta-Analysis)
Meta-Analysis
BACKGROUND
To contribute to the WHO initiative, VISION 2020: The Right to Sight, an assessment of global vision impairment in 2020 and temporal change is needed. We aimed to extensively update estimates of global vision loss burden, presenting estimates for 2020, temporal change over three decades between 1990-2020, and forecasts for 2050.
METHODS
We did a systematic review and meta-analysis of population-based surveys of eye disease from January, 1980, to October, 2018. Only studies with samples representative of the population and with clearly defined visual acuity testing protocols were included. We fitted hierarchical models to estimate 2020 prevalence (with 95% uncertainty intervals [UIs]) of mild vision impairment (presenting visual acuity ≥6/18 and <6/12), moderate and severe vision impairment (<6/18 to 3/60), and blindness (<3/60 or less than 10° visual field around central fixation); and vision impairment from uncorrected presbyopia (presenting near vision
vision loss up to 2050. FINDINGS
In 2020, an estimated 43·3 million (95% UI 37·6-48·4) people were blind, of whom 23·9 million (55%; 20·8-26·8) were estimated to be female. We estimated 295 million (267-325) people to have moderate and severe vision impairment, of whom 163 million (55%; 147-179) were female; 258 million (233-285) to have mild vision impairment, of whom 142 million (55%; 128-157) were female; and 510 million (371-667) to have visual impairment from uncorrected presbyopia, of whom 280 million (55%; 205-365) were female. Globally, between 1990 and 2020, among adults aged 50 years or older, age-standardised prevalence of blindness decreased by 28·5% (-29·4 to -27·7) and prevalence of mild vision impairment decreased slightly (-0·3%, -0·8 to -0·2), whereas prevalence of moderate and severe vision impairment increased slightly (2·5%, 1·9 to 3·2; insufficient data were available to calculate this statistic for vision impairment from uncorrected presbyopia). In this period, the number of people who were blind increased by 50·6% (47·8 to 53·4) and the number with moderate and severe vision impairment increased by 91·7% (87·6 to 95·8). By 2050, we predict 61·0 million (52·9 to 69·3) people will be blind, 474 million (428 to 518) will have moderate and severe vision impairment, 360 million (322 to 400) will have mild vision impairment, and 866 million (629 to 1150) will have uncorrected presbyopia.
INTERPRETATION
Age-adjusted prevalence of blindness has reduced over the past three decades, yet due to population growth, progress is not keeping pace with needs. We face enormous challenges in avoiding vision impairment as the global population grows and ages.
FUNDING
Brien Holden Vision Institute, Fondation Thea, Fred Hollows Foundation, Bill & Melinda Gates Foundation, Lions Clubs International Foundation, Sightsavers International, and University of Heidelberg.
Topics: Aged; Aged, 80 and over; Blindness; Cataract; Eye Diseases; Female; Forecasting; Glaucoma; Global Burden of Disease; Global Health; Humans; Macular Degeneration; Male; Middle Aged; Presbyopia; Vision, Low; Visual Acuity
PubMed: 33275950
DOI: 10.1016/S2214-109X(20)30425-3 -
Eye (London, England) Aug 2018Numerous studies have demonstrated physical activity is a strong factor in overall health and well-being, and a growing body of literature, reviewed herein, suggests... (Review)
Review
Numerous studies have demonstrated physical activity is a strong factor in overall health and well-being, and a growing body of literature, reviewed herein, suggests that several eye conditions, including glaucoma, age-related macular degeneration, and diabetic retinopathy, are associated with lower activity levels. Likewise, physical activity levels are lower in persons with worse vision. Research in this area has utilized both self-reported physical activity measures as well as objective measures of activity (i.e., accelerometers), each of which have their own strengths and limitations. Putative mechanisms explaining the association of various eye conditions with physical activity are discussed. It is possible that activity restriction occurs as a downstream consequence of eye disease/visual impairment, that activity restriction causes eye disease/visual impairment, or that causality is bidirectional; evidence supporting each of these theories is put forth. An improved understanding of the relationship between physical activity and eye disease will highlight potential secondary health risks resulting from eye disease, and can help determine whether activity might serve as a readily available preventative measure to prevent specific eye conditions.
Topics: Exercise; Eye Diseases; Humans; Quality of Life; Vision, Low; Visual Acuity
PubMed: 29610523
DOI: 10.1038/s41433-018-0081-8 -
The Cochrane Database of Systematic... Jan 2020Low vision rehabilitation aims to optimise the use of residual vision after severe vision loss, but also aims to teach skills in order to improve visual functioning in... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Low vision rehabilitation aims to optimise the use of residual vision after severe vision loss, but also aims to teach skills in order to improve visual functioning in daily life. Other aims include helping people to adapt to permanent vision loss and improving psychosocial functioning. These skills promote independence and active participation in society. Low vision rehabilitation should ultimately improve quality of life (QOL) for people who have visual impairment.
OBJECTIVES
To assess the effectiveness of low vision rehabilitation interventions on health-related QOL (HRQOL), vision-related QOL (VRQOL) or visual functioning and other closely related patient-reported outcomes in visually impaired adults.
SEARCH METHODS
We searched relevant electronic databases and trials registers up to 18 September 2019.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) investigating HRQOL, VRQOL and related outcomes of adults, with an irreversible visual impairment (World Health Organization criteria). We included studies that compared rehabilitation interventions with active or inactive control.
DATA COLLECTION AND ANALYSIS
We used standard methods expected by Cochrane. We assessed the certainty of the evidence using the GRADE approach.
MAIN RESULTS
We included 44 studies (73 reports) conducted in North America, Australia, Europe and Asia. Considering the clinical diversity of low vision rehabilitation interventions, the studies were categorised into four groups of related intervention types (and by comparator): (1) psychological therapies and/or group programmes, (2) methods of enhancing vision, (3) multidisciplinary rehabilitation programmes, (4) other programmes. Comparators were no care or waiting list as an inactive control group, usual care or other active control group. Participants included in the reported studies were mainly older adults with visual impairment or blindness, often as a result of age-related macular degeneration (AMD). Study settings were often hospitals or low vision rehabilitation services. Effects were measured at the short-term (six months or less) in most studies. Not all studies reported on funding, but those who did were supported by public or non-profit funders (N = 31), except for two studies. Compared to inactive comparators, we found very low-certainty evidence of no beneficial effects on HRQOL that was imprecisely estimated for psychological therapies and/or group programmes (SMD 0.26, 95% CI -0.28 to 0.80; participants = 183; studies = 1) and an imprecise estimate suggesting little or no effect of multidisciplinary rehabilitation programmes (SMD -0.08, 95% CI -0.37 to 0.21; participants = 183; studies = 2; I = 0%); no data were available for methods of enhancing vision or other programmes. Regarding VRQOL, we found low- or very low-certainty evidence of imprecisely estimated benefit with psychological therapies and/or group programmes (SMD -0.23, 95% CI -0.53 to 0.08; studies = 2; I = 24%) and methods of enhancing vision (SMD -0.19, 95% CI -0.54 to 0.15; participants = 262; studies = 5; I = 34%). Two studies using multidisciplinary rehabilitation programmes showed beneficial but inconsistent results, of which one study, which was at low risk of bias and used intensive rehabilitation, recorded a very large and significant effect (SMD: -1.64, 95% CI -2.05 to -1.24), and the other a small and uncertain effect (SMD -0.42, 95%: -0.90 to 0.07). Compared to active comparators, we found very low-certainty evidence of small or no beneficial effects on HRQOL that were imprecisely estimated with psychological therapies and/or group programmes including no difference (SMD -0.09, 95% CI -0.39 to 0.20; participants = 600; studies = 4; I = 67%). We also found very low-certainty evidence of small or no beneficial effects with methods of enhancing vision, that were imprecisely estimated (SMD -0.09, 95% CI -0.28 to 0.09; participants = 443; studies = 2; I = 0%) and multidisciplinary rehabilitation programmes (SMD -0.10, 95% CI -0.31 to 0.12; participants = 375; studies = 2; I = 0%). Concerning VRQOL, low-certainty evidence of small or no beneficial effects that were imprecisely estimated, was found with psychological therapies and/or group programmes (SMD -0.11, 95% CI -0.24 to 0.01; participants = 1245; studies = 7; I = 19%) and moderate-certainty evidence of small effects with methods of enhancing vision (SMD -0.24, 95% CI -0.40 to -0.08; participants = 660; studies = 7; I = 16%). No additional benefit was found with multidisciplinary rehabilitation programmes (SMD 0.01, 95% CI -0.18 to 0.20; participants = 464; studies = 3; I = 0%; low-certainty evidence). Among secondary outcomes, very low-certainty evidence of a significant and large, but imprecisely estimated benefit on self-efficacy or self-esteem was found for psychological therapies and/or group programmes versus waiting list or no care (SMD -0.85, 95% CI -1.48 to -0.22; participants = 456; studies = 5; I = 91%). In addition, very low-certainty evidence of a significant and large estimated benefit on depression was found for psychological therapies and/or group programmes versus waiting list or no care (SMD -1.23, 95% CI -2.18 to -0.28; participants = 456; studies = 5; I = 94%), and moderate-certainty evidence of a small benefit versus usual care (SMD -0.14, 95% CI -0.25 to -0.04; participants = 1334; studies = 9; I = 0%). ln the few studies in which (serious) adverse events were reported, these seemed unrelated to low vision rehabilitation.
AUTHORS' CONCLUSIONS
In this Cochrane Review, no evidence of benefit was found of diverse types of low vision rehabilitation interventions on HRQOL. We found low- and moderate-certainty evidence, respectively, of a small benefit on VRQOL in studies comparing psychological therapies or methods for enhancing vision with active comparators. The type of rehabilitation varied among studies, even within intervention groups, but benefits were detected even if compared to active control groups. Studies were conducted on adults with visual impairment mainly of older age, living in high-income countries and often having AMD. Most of the included studies on low vision rehabilitation had a short follow-up, Despite these limitations, the consistent direction of the effects in this review towards benefit justifies further research activities of better methodological quality including longer maintenance effects and costs of several types of low vision rehabilitation. Research on the working mechanisms of components of rehabilitation interventions in different settings, including low-income countries, is also needed.
Topics: Depression; Humans; Quality of Life; Randomized Controlled Trials as Topic; Self Efficacy; Vision, Low
PubMed: 31985055
DOI: 10.1002/14651858.CD006543.pub2 -
Turkish Journal of Ophthalmology Jun 2019With increased life expectancy at birth and especially the rising incidence of age-related macular degeneration, low vision (re)habilitation is becoming more important... (Review)
Review
With increased life expectancy at birth and especially the rising incidence of age-related macular degeneration, low vision (re)habilitation is becoming more important today. Important factors to consider when presenting rehabilitation and treatment options to patients presenting to low vision centers include the diagnosis of the underlying disease, the patient’s age, their existing visual functions (especially distance and near visual acuity), whether visual loss is central or peripheral, whether their disease is progressive or not, the patient’s education level, and their expectations from us. Low vision patients must be guided to the right centers at the appropriate age, with appropriate indications, and with realistic expectations, and the rehabilitation process must be carried out as a multidisciplinary collaboration.
Topics: Humans; Ophthalmology; Vision, Low; Visual Acuity
PubMed: 31245978
DOI: 10.4274/tjo.galenos.2018.53325 -
Annual Review of Vision Science Oct 2016Low vision is any type of visual impairment that affects activities of daily living. In the context of low vision, we define plasticity as changes in brain or perceptual... (Review)
Review
Low vision is any type of visual impairment that affects activities of daily living. In the context of low vision, we define plasticity as changes in brain or perceptual behavior that follow the onset of visual impairment and that are not directly due to the underlying pathology. An important goal of low-vision research is to determine how plasticity affects visual performance of everyday activities. In this review, we consider the levels of the visual system at which plasticity occurs, the impact of age and visual experience on plasticity, and whether plastic changes are spontaneous or require explicit training. We also discuss how plasticity may affect low-vision rehabilitation. Developments in retinal imaging, noninvasive brain imaging, and eye tracking have supplemented traditional clinical and psychophysical methods for assessing how the visual system adapts to visual impairment. Findings from contemporary research are providing tools to guide people with low vision in adopting appropriate rehabilitation strategies.
Topics: Contrast Sensitivity; Humans; Neuronal Plasticity; Optical Imaging; Vision, Low; Visual Acuity; Visual Fields; Visual Perception
PubMed: 28532346
DOI: 10.1146/annurev-vision-111815-114344 -
Clinical & Experimental Optometry Jul 2020Despite orientation and mobility (O&M) being a significant factor determining quality of life of people with low vision or blindness, there are no gold standard measures... (Review)
Review
Despite orientation and mobility (O&M) being a significant factor determining quality of life of people with low vision or blindness, there are no gold standard measures or agreement on how to measure O&M performance. In the first part of this systematic review, an inventory of O&M outcome measures used by recent studies to assess the performance of orientation and/or mobility of adults with vision impairment (low vision and blindness) is presented. A wide variety of O&M outcome measures have been implemented in different fields of study, such as epidemiologic research and interventional studies evaluating training, assistive technology, vision rehabilitation and vision restoration. The most frequent aspect of outcome measures is efficiency such as time, distance, speed and percentage of preferred walking speed, followed by obstacle contacts and avoidance, and dis/orientation and veering. Other less commonly used aspects are target identification, safety and social interaction and self-reported outcome measures. Some studies employ sophisticated equipment to capture and analyse O&M performance in a laboratory setting, while others carry out their assessment in real-world indoor or outdoor environments. In the second part of this review, the appropriateness of implementing the identified outcome measures to assess O&M performance in clinical and functional O&M practice is evaluated. Nearly a half of these outcome measures meet all four criteria of face validity (either clinical or functional), responsiveness, reliability and feasibility and have the potential to be implemented in clinical or functional O&M practice. The findings of this review confirm the complicated and dynamic nature of O&M. Multiple measures are required in any evaluation of O&M performance to facilitate holistic assessment of O&M abilities and limitations of each individual.
Topics: Humans; Orientation; Outcome Assessment, Health Care; Quality of Life; Vision, Low; Walking
PubMed: 31838758
DOI: 10.1111/cxo.13004 -
The Gerontologist Jun 2016Given the centrality of risk in geriatric rehabilitation, it is critically important to attend to how conceptualizations of risk shape research, policies, and... (Review)
Review
PURPOSE
Given the centrality of risk in geriatric rehabilitation, it is critically important to attend to how conceptualizations of risk shape research, policies, and rehabilitation practices. This paper presents a critical interpretive synthesis (CIS) of literature addressing risk and low vision rehabilitation for older adults with age-related vision loss (ARVL) to identify key guiding assumptions regarding risk and discuss implications for what gets attended to, and not attended to, within research and rehabilitation.
DESIGN AND METHODS
This CIS combined guidelines proposed by Dixon-Woods and colleagues (2006-Conducting a critical interpretive synthesis of the literature on access to healthcare by vulnerable groups. BMC Medical Research Methodology, 6, 35) and Alvesson and Sandberg (2011-Generating research questions through problematization. Academy of Management Review, 36, 247-271; 2013-Constructing research questions: Doing interesting research. London: Sage). The iterative review process involved 3 steps: literature search and selection, data extraction, and syntheses to identify boundary assumptions. The dataset included 83 research and practice description articles.
RESULTS
Older adults with ARVL were constructed as "at risk" for various adverse outcomes, particularly dependency and self-harm, and as posing risks to others. An epidemiological approach to risk based in assumptions aligned with a technico-scientific perspective was dominant, with risk conceptualized as an embodied, individual-level phenomenon that is to be determined and managed through objective screening and expert monitoring.
IMPLICATIONS
Key concerns include a lack of: attention to the tensions created when rehabilitation research and practice attempt to promote independence while simultaneously reducing risk, incorporation of aging adults' perspectives on risk, and analysis of environmental factors that shape risks. Research that starts by valuing older adults' experiences and attends to context can inform rehabilitation practices that support health-promoting, risk-taking, and facilitate collaborative approaches to risk management.
Topics: Aged; Aged, 80 and over; Aging; Disability Evaluation; Geriatric Assessment; Humans; Risk; Risk Assessment; Vision, Low
PubMed: 26888757
DOI: 10.1093/geront/gnv685 -
Indian Journal of Ophthalmology Mar 2016Oculodentodigital dysplasia is a rare, autosomal dominant disorder with high penetrance and variable expressivity, caused by mutations in the connexin 43 or gap junction...
Oculodentodigital dysplasia is a rare, autosomal dominant disorder with high penetrance and variable expressivity, caused by mutations in the connexin 43 or gap junction protein alpha-1 gene. It has been diagnosed in fewer than 300 people worldwide with an incidence of around 1 in 10 million. It affects many parts of the body, particularly eyes (oculo), teeth (dento), and fingers and/or toes (digital). The common clinical features include facial dysmorphism with thin nose, microphthalmia, syndactyly, tooth anomalies such as enamel hypoplasia, anodontia, microdontia, early tooth loss and conductive deafness. Other less common features are abnormalities of the skin and its appendages, such as brittle nails, sparse hair, and neurological abnormalities. To prevent this syndrome from being overlooked, awareness of possible symptoms is necessary. Early recognition can prevent blindness, dental problems and learning disabilities. Described here is the case of a 21-year-old male who presented to the ophthalmology outpatient department with a complaint of bilateral progressive loss of vision since childhood.
Topics: Abnormalities, Multiple; Craniofacial Abnormalities; Eye Abnormalities; Foot Deformities, Congenital; Humans; Male; Microphthalmos; Syndactyly; Tooth Abnormalities; Vision, Low; Visual Acuity; Young Adult
PubMed: 27146935
DOI: 10.4103/0301-4738.180191