Estimates of the prevalence of visual impairment caused by uncorrected refractive errors in 2004 have been determined at regional and global levels for people aged 5 years and over from recent ...published and unpublished surveys. The estimates were based on the prevalence of visual acuity of less than 6/18 in the better eye with the currently available refractive correction that could be improved to equal to or better than 6/18 by refraction or pinhole. A total of 153 million people (range of uncertainty: 123 million to 184 million) are estimated to be visually impaired from uncorrected refractive errors, of whom eight million are blind. This cause of visual impairment has been overlooked in previous estimates that were based on best-corrected vision. Combined with the 161 million people visually impaired estimated in 2002 according to best-corrected vision, 314 million people are visually impaired from all causes: uncorrected refractive errors become the main cause of low vision and the second cause of blindness. Uncorrected refractive errors can hamper performance at school, reduce employability and productivity, and generally impair quality of life. Yet the correction of refractive errors with appropriate spectacles is among the most cost-effective interventions in eye health care. The results presented in this paper help to unearth a formerly hidden problem of public health dimensions and promote policy development and implementation, programmatic decision-making and corrective interventions, as well as stimulate research.
Global data on visual impairment in the year 2002 RESNIKOFF, Serge; PASCOLINI, Donatella; ETYA'ALE, Daniel ...
Bulletin of the World Health Organization,
11/2004, Letnik:
82, Številka:
11
Journal Article
Recenzirano
Odprti dostop
This paper presents estimates of the prevalence of visual impairment and its causes in 2002, based on the best available evidence derived from recent studies. Estimates were determined from data on ...low vision and blindness as defined in the International statistical classification of diseases, injuries and causes of death, 10th revision. The number of people with visual impairment worldwide in 2002 was in excess of 161 million, of whom about 37 million were blind. The burden of visual impairment is not distributed uniformly throughout the world: the least developed regions carry the largest share. Visual impairment is also unequally distributed across age groups, being largely confined to adults 50 years of age and older. A distribution imbalance is also found with regard to gender throughout the world: females have a significantly higher risk of having visual impairment than males. Notwithstanding the progress in surgical intervention that has been made in many countries over the last few decades, cataract remains the leading cause of visual impairment in all regions of the world, except in the most developed countries. Other major causes of visual impairment are, in order of importance, glaucoma, age-related macular degeneration, diabetic retinopathy and trachoma.
Trachoma is the leading cause of infectious blindness worldwide. It is known to be highly correlated with poverty, limited access to healthcare services and water. In 2003, the WHO estimated that 84 ...million people were suffering from active trachoma, and 7.6 million were severely visually impaired or blind as a result of trachoma: this study provides an updated estimate of the global prevalence of trachoma based on the most recent information available.
A literature search of recent published and unpublished surveys in the 57 endemic countries was carried out: the result of surveys that used the WHO trachoma grading system and additional information from regional and country experts served as a basis to determine the prevalence of trachoma in each country.
Population-based surveys provided recent information for 42 out of 57 endemic countries. 40.6 million people are estimated to be suffering from active trachoma, and 8.2 million are estimated to have trichiasis.
The current estimate of prevalence of trachoma is lower than the previous WHO estimates: this can be explained by the success in implementing control strategy, by more accurate data, as well as by socio-economic development in endemic countries.
PURPOSE For the past 25 years, the WHO Programme for the Prevention of Blindness and Deafness has maintained a Global Data Bank on visual impairment with the purpose of storing the available ...epidemiological data on blindness and low vision. The Data Bank has now been updated to include studies conducted since the last update in 1994. METHODS An extensive literature search was conducted in international and national scientific and medical journals to identify epidemiological studies that fulfilled basic criteria for inclusion in the Data Bank, namely a clearly stated definition of blindness and low vision, and prevalence rates derived from population-based surveys. Sources such as National Prevention of Blindness Programmes, academic institutions or WHO country or regional reports were also investigated. RESULTS Two-hundred-and-eight population-based studies on visual impairment for 68 countries are reported in detail, providing an up-to-date, comprehensive compilation of the available information on visual impairment and its causes globally.
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.
Corneal opacities (COs) are among the top 5 causes of blindness worldwide, yet the global prevalence, regional differences, and risk factors are unclear.
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.
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).
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.
The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Abstract
Hearing and vision impairment are highly prevalent in ageing individuals and are significant public health concerns given their meaningful impacts on individuals and society. Yet, many cases ...of both visual and hearing impairment remain unidentified and thus, unaddressed. This article describes the rationale and process of monitoring for visual and hearing impairment in older adults, by summarising guidance and resources available from the World Health Organisation (WHO) that were developed based upon the best current available evidence. It is recommended that vision screening be offered at least annually to adults aged over 50 years and hearing screening be offered every 5 years to adults aged 50–64 years, and every 1–3 years to adults aged 65 years or older. Both hearing and vision screening can be conducted in community, home or clinical settings by trained health workers with simple equipment. More specifically, vision screening can be conducted with a simple eye chart. Hearing screening can be conducted without specialised equipment by using pure tones set to a fixed level, an automated mobile- or web-based digits-in-noise test, or the whispered voice test. Hearing screening can also be conducted in audiology clinics using pure-tone air conduction threshold testing. There exists WHO guidance to support the monitoring of hearing and vision impairment, which, when warranted, can facilitate referral for comprehensive assessment and prompt appropriate, person-centred interventions to mitigate the negative consequences of hearing and vision impairment.
ObjectiveKnowledge of a patient’s emotional health status and using patient-centred communication may be key to providing early intervention and referral to appropriate treatment/support services for ...ophthalmology patients. This study aims to determine if and how ophthalmologists use anxiety and depression scores to determine clinical care of patients with chronic eye disease.Methods and analysisThis cross-sectional study included 10 ophthalmologists and a convenience sample of 100 of their patients (>18 years). The Patient Health Questionnaire (PHQ-9) for depression and the Generalised Anxiety Disorder (GAD-7) tool were administered to patients. Scores from these instruments were provided to ophthalmologists just prior to the clinic visit. After the visit, ophthalmologists were given a questionnaire to assess self-reported change in clinical practice and whether knowledge of scores impacted their communication style, treatment plan and follow-up protocol.ResultsOf these patients (mean age=63), 27% reported mild-moderate anxiety or depression as their worst score, while 2% reported suicidal thoughts; 20% reported neither anxiety nor depression. Ophthalmologists’ response to patients with mild or worse anxiety or depression was to change clinical approach (28%) and communication style (31%), both metrics increasing with severity of symptoms (Fisher’s exact p<0.05). None reported changing their choice of treatment or modifying follow-up protocols; referral to social work/psychiatry services was 60%, 3.7% and 0% for patients with moderately severe or worse, mild-to-moderate, or minimal scores, respectively.ConclusionProviding ophthalmologists with knowledge of the emotional health of their patients may change the clinical approach and referral pattern.
To estimate the population health effects, costs and cost effectiveness of selected cataract surgery interventions in areas of the world with different epidemiological profiles.
Effectiveness ...estimates are based on a review of the literature taking into account factors such as operative failure, complications and patient non-compliance. A population model was applied to follow the lifelong impact on individuals having cataract surgery. Costing estimates are based on primary data collected in 14 epidemiological subregions by regional costing teams and on a literature review. Costings were estimated for different geographical coverage levels using non-linear cost functions.
Intra- and extra-capsular cataract surgeries are cost-effective ways to reduce the impact of cataract-blindness. Extra-capsular cataract surgery is more cost-effective than intra-capsular surgery in all regions considered. Providing extra-capsular cataract surgery to 95% of those who need it (95% coverage level) would avert over 3.5 million disability-adjusted life years (DALYs) per year globally. The cost-effectiveness ranges from 57 International dollars (1 dollar) per DALY in the WHO South-East Asia Region where there is high overall child and adult mortality to 1 dollar 2307 per DALY in the WHO Western Pacific Region where there is low overall child and adult mortality.
Extra-capsular surgery for cataracts at a high level of coverage is the most cost-effective way of restoring sight in all epidemiological subregions considered. Analysts from countries within a region are encouraged to further contextualize the results based on their own country's specific parameters.
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