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Purpose To assess the influence of distance and near visual impairment on self-reported near visual functioning (VF) among adults in a multi-country study. Design Population-based cross-sectional study. Participants Participants aged ≥35 years were randomly selected with cluster sampling at seven sites: rural sites in Nepal (Kaski) and India (Madurai), a semi-rural site in China (Shunyi), semi-urban sites in South Africa (Durban) and Niger (Dosso), and urban sites in the United States (Los Angeles) and China (Guangzhou). Methods Binocular presenting distance and near visual acuity (VA) were measured with a LogMAR tumbling E chart at 4 meters and 40 cm, respectively. A 12-item near VF questionnaire interview was administered by trained local interviewers, with responses scored from 100 to 0 as visual “disability” increased. Multiple linear regression was used to investigate the association of age, gender, education and VA with overall eyesight, difficulty with activities and social functioning subscale scores. Main Outcome Measures VF subscale scores. Results The study sample consisted of 6,851 questionnaire respondents. The VF subscale scores decreased significantly with worse distance and near VA, and even mildly impaired VA could result in reduced VF at all sites. In multiple linear regression modeling, lower VF subscale scores were associated with older age in four sites, female gender in three sites, and greater education in two sites. The influence of near VA was greater than that of distance VA in three sites, and in one site distance VA was more influential than near VA. With study site included in the regression modeling, lower scores for the overall eyesight subscale (compared to the Shunyi reference site) were found in Guangzhou, Kaski and Durban; lower difficulty in activities scores were found in Kaski and Durban, but better scores in Guangzhou and Madurai; social functioning scores were lower in Kaski, Durban and Dosso. Conclusions Along the entire VA spectrum, lower levels of distance and near VA led to significant reductions in VF subscale scores, with wide variation both within and between study sites. The impact of near vision on VF should receive greater emphasis with further investigation in various socio-economic and cultural settings.

The burden of vision impairment due to uncorrected refractive error (needing spectacles) in Mozambique is known to be significant. To improve the planning and provision of eye health services, a better understanding of how vision is valued by patients is needed. The willingness to pay (WTP) for improved vision through correcting refractive error was investigated in Nampula, Mozambique, using stated choice and bidding game methodologies. The mean WTP values were found to be 388.92 Meticals (US$13) for stated choice and 469.89 Meticals (US$16) for the bidding game. The mean WTP values for rural dwellers were found to be lower than responses from those living in urban areas. If avoidable vision impairment is to be addressed in Mozambique, the cost of services must not be a barrier and the construction of a sustainable spectacle system that delivers for both rural and urban patients must be a priority.

BACKGROUND:The growing global burden of vision impairment makes it imperative that there are appropriately trained human resources. Optometrists play a critical role in alleviating this burden, but the low number of optometrists available or the numbers in different countries has always been a challenge for eye care planning. Despite this, there have been limited studies conducted to quantify the deficits in the number of optometrists globally. Methods:A standardised English language questionnaire was used in this cross-sectional study to determine the number and distribution of optometrists globally between February 2017 and May 2020. The survey was translated where necessary and completed by key informants. Using the World Council of Optometry’s scope of practice guidelines, optometrists were defined at levels 2 to 4. Optometrist-to-population ratios were calculated for all countries and regions and compared to targets of 1:50 000 (in developing contexts) or 1:10 000 (in developed contexts).Results:An overall response rate of 80.9% was achieved with responses from 123 of the 152 countries invited. Most (40.7%) key informants were academics. The total number of optometrists across 21 Global Burden of Disease (GBD) regions was 331,781 as of 2019. Sixty-six (53.7%) of 123 countries met the 1:50,000 Optometrist-to-population ratio. A strong (r=0.7) direct positive relationship existed between age-standardised prevalences of blindness and mild- and severe-vision impairment and optometrist-to-population ratios. Strong inverse relationships were observed between country GDP and optometrist-to-population ratio.Conclusion:High-income countries met the target for optometrist-to-patient ratios, while low-to-, middle-income countries and low-income countries did not meet the targets. Low optometrist-to-patient ratios were strongly associated with a higher magnitude of blindness and vision impairment.

Background: Diabetes mellitus (DM) and diabetic retinopathy (DR) are important issues in the district health system (DHS) of South Africa (SA). Guidelines for the management of DR in SA were developed more than a decade ago but not effectively implemented.Aim: The aim of this study was to develop a suitable model for DR that could be effectively implemented by a team of healthcare practitioners (HCPs) to co-manage DM and DR in the DHS of SA.Setting: The study was conducted through Voortrekker District Hospital, Limpopo Province, SA.Methods: A saturated strategy sample study was employed, and questionnaires were distributed to 24 endocrinologists in both private and public practices in Gauteng Province and to three ophthalmologists and 10 medical officers (MOs) in ophthalmology in health institutions in Waterberg and Capricorn districts of Limpopo Province. The questionnaires distributed included questions relating to the recommended roles of primary healthcare (PHC) nurses, MOs in general practice, MOs in ophthalmology, ophthalmic nurses, optometrists, and ophthalmologists to manage patients with DM in the public sector. The Delphi technique was employed requiring experts to comment qualitatively and quantitatively to elicit the required information.Results: At PHC level, PHC nurses are to document a comprehensive patient case history and assess vitals before referring to MOs in general practice. Medical officers in general practice are to assess DM control and screen for target organ disease. All patients with DM are to be referred to optometrists for retinal photography. Optometrists and ophthalmic nurses are to detect, grade and monitor pre-proliferative stages of DR, and refer to MOs in ophthalmology or ophthalmologists at district or tertiary hospitals for surgical intervention or treatment.Conclusion: Based on the expertise of the endocrinologists and ophthalmologists concerned, a DR screening model for a DHS was proposed, reflecting the role of HCPs in the management of DM and DR in the DHS of Limpopo Province, SA.

Background: The development of human resources for eye health (HReH), aimed at achieving a 25% reduction in visual impairment by the year 2020, was one of the VISION 2020 objectives. Aim: To assess HReH in the public sector of KwaZulu-Natal (KZN), and its effect on the accessibility of eye care in the province. Setting: All public eye facilities in KZN. Methods: A quantitative cross-sectional study using a close-ended questionnaire to assess distribution and outputs of HReH. At the end of the questionnaire, respondents gave general comments on their ability to provide services. Results: Human resource rates were 0.89 for ophthalmologists, 2.44 for cataract surgeons, 4.8 for optometrists and 4.7 for ophthalmic nurses per 1 million population. Most health facilities had some HReH working in them, albeit none had dispensing opticians. Regression analysis showed that 67.1% of variation in cataract surgery was because of the number of surgeons available. Cataract surgical rates were low with a waiting period of up to 18 months. In addition to the refractive error regression analysis of 33.7%, spectacle supply was low, with a backlog of up to 9 months in some facilities. Conclusion: Overall, HReH targets as per VISION 2020 and the National Prevention of Blindness have not been met in this region. Dispensing opticians are not employed in any of the province’s health districts. An increase in the eye health workforce is necessary to improve the eye health outcomes for people dependent on public eye facilities.

SIGNIFICANCE: Uncorrected refractive error is the leading cause of visual impairment; therefore, reducing its prevalence is important worldwide. For two decades, there has not been a comprehensive assessment of refractive error in Latin America. PURPOSE: The purpose of this study was to determine the current prevalence of refractive error, presbyopia, spectacle coverage, barriers to uptake refractive services, and spectacle correction in people 15 years and older in Bogotá, Colombia. METHODS: A cross-sectional community-based survey was conducted using 50 randomly selected clusters from 10 districts of Bogotá reflecting the socioeconomic status of the city. Respondents 15 years and older were interviewed and underwent standardized clinical eye examinations. Prevalence of uncorrected refractive error, spectacle coverage, and visual impairment were standardized to 2015 age-sex population distribution of Bogotá and further analyzed. RESULTS: A total of 2886 subjects (90% of 3206 eligible subjects) participated in the study; 39.1% were male and 60.9% were female in the age range of 15 to 96 years, with a median age of 46 years (interquartile range, 45 to 54 years). Age- and sex-standardized prevalence of visual impairment was 19.3% (95% confidence interval [CI], 17.8 to 20.8%). Prevalence of uncorrected refractive error was 12.5% (95% CI, 11.3 to 13.7%). Prevalence of presbyopia among participants 35 years and older was 55.2% (95% CI, 52.9 to 57.4%). Spectacle coverage was 50.9% for distance vision, and it was 33.9% for presbyopia. Main barrier to spectacle uptake was a limitation in affording spectacles because of economic factors (29.5%). CONCLUSIONS: This study provides a current estimate of refractive error using the Rapid Assessment of Refractive Error for Colombia and the Latin American region. The prevalence of uncorrected refractive error and presbyopia was high, and the barriers to spectacle uptake were higher in the lowest socioeconomic strata. The results obtained in the present study will help in making evidence-based decisions related to eye care service delivery in Colombia.

Purpose We estimated the potential global economic productivity loss resulting from vision impairment (VI) and blindness as a result of uncorrected myopia and myopic macular degeneration (MMD) in 2015. Clinical Relevance Understanding the economic burden of VI associated with myopia is critical to addressing myopia as an increasingly prevalent public health problem. Methods We estimated the number of people with myopia and MMD corresponding to critical visual acuity thresholds. Spectacle correction coverage was analyzed against country-level variables from the year of data collection; variation in spectacle correction was described best by a model based on a human development index, with adjustments for urbanization and age. Spectacle correction and myopia data were combined to estimate the number of people with each level of VI resulting from uncorrected myopia. We then applied disability weights, labor force participation rates, employment rates, and gross domestic product per capita to estimate the potential productivity lost among individuals with each level and type of VI resulting from myopia in 2015 in United States dollars (US$). An estimate of care-associated productivity loss also was included. Results People with myopia are less likely to have adequate optical correction if they are older and live in a rural area of a less developed country. The global potential productivity loss associated with the burden of VI in 2015 was estimated at US$244 billion (95% confidence interval [CI], US$49 billion–US$697 billion) from uncorrected myopia and US$6 billion (95% CI, US$2 billion—US$17 billion) from MMD. Our estimates suggest that the Southeast Asia, South Asia, and East Asia Global Burden of Disease regions bear the greatest potential burden as a proportion of their economic activity, whereas East Asia bears the greatest potential burden in absolute terms. Conclusions Even under conservative assumptions, the potential productivity loss associated with VI and blindness resulting from uncorrected myopia is substantially greater than the cost of correcting myopia.

With the growing prevalence of myopia, already at epidemic levels in some countries, there is an urgent need for new management approaches. However, with the increasing number of research publications on the topic of myopia control, there is also a clear necessity for agreement and guidance on key issues, including on how myopia should be defined and how interventions, validated by well-conducted clinical trials, should be appropriately and ethically applied. The International Myopia Institute (IMI) reports the critical review and synthesis of the research evidence to date, from animal models, genetics, clinical studies, and randomized controlled trials, by more than 85 multidisciplinary experts in the field, as the basis for the recommendations contained therein. As background to the need for myopia control, the risk factors for myopia onset and progression are reviewed. The seven generated reports are summarized: (1) Defining and Classifying Myopia, (2) Experimental Models of Emmetropization and Myopia, (3) Myopia Genetics, (4) Interventions for Myopia Onset and Progression, (5) Clinical Myopia Control Trials and Instrumentation, (6) Industry Guidelines and Ethical Considerations for Myopia Control, and (7) Clinical Myopia Management Guidelines.

Background: Diabetic retinopathy (DR) screening programmes have been developed and implemented in different countries based on availability of resources. Most protocols developed for DR have been solely dedicated to DR screening without involving systemic screening. Aim: To implement and evaluate a DR screening model utilising a team of healthcare practitioners (HCPs) to manage diabetes mellitus (DM) to reduce DR progression. Setting: Primary healthcare clinics and Voortrekker hospital in Waterberg district of Limpopo province. Methods: A cross-sectional study was conducted, in which a total of 107 patients with DM from seven clinics consented to participation. A proposed DR screening model was implemented where patients with DM were screened for systemic complications at clinics and referred to Voortrekker district hospital for retinal photography. Questionnaire responses evaluated the success of the screening process and operational challenges. Results: From the study population, 32 (29.1%) were male and 75 (70.1%) were female. The mean age of patients was 63.7 years with a mean weight of 80.69 kg. The mean duration of DM was 9.26 years and the mean haemoglobin A1c (HbA1c) level was 9.7%. From the 47 patients who had visual acuity less than 6/9, 74.5% had refractive error. About 10% (9.4%) had DR or diabetic macular oedema (DME) and 38.3% had other lesions. Referral to an ophthalmologist was necessary in 36.5% of cases. Conclusion: The implementation of a team approach to co-manage DM and DR utilising the developed protocol improved the quality of care for patients with DM in the district health system.

Background: Low vision and blindness have significant implications, resulting in a generally reduced quality of life amongst the sufferers. Aim: To determine the prevalence and causes of low vision and blindness amongst learners at the Akropong School for the Blind. Setting: The study was conducted in Akropong School for the Blind, Ghana. Methods: A cross-sectional study design was used. Eye examinations included measurements of presenting distance visual acuity (PDVA) with the Tumbling ‘E’ distance LogMAR chart. Anterior and posterior segments were examined with an ophthalmoscope and a slit lamp. Results: Two hundred and sixty-eight ( N = 268) learners comprising 157 (58.6%) males and 111 (41.4%) females took part in this study and their ages ranged from 4 to 43 years (mean and standard deviation [SD] = 15.79 ± 6.15 years). The results indicated that 76.1% were classified as blind and 23.9% of the learners had low vision. The leading cause of low vision was glaucoma (39.1%) followed by pseudophakia (21.9%) and retinopathy (18.8%). The most common causes of low vision and blindness based on pathology found on ocular anatomical structures were corneal opacity/phthisis bulbi (35.5%), followed by glaucoma (25%), cataract (13.4%) and retinopathy (10.8%). Conclusion: The leading causes of low vision and blindness identified in this study were because of avoidable diseases such as corneal opacity/phthisis bulbi and glaucoma. This highlighted the need for adequate primary eye care services, equitable eye health workforce distribution and eye health awareness in Ghana to help prevent low vision and blindness.

Background: Without appropriate interventions, simple or low myopia can progressively get worse and lead to high myopia. Patients with high myopia are at a greater risk of developing retinal detachment, myopic macular degeneration, glaucoma and eventual blindness in some cases, and hence the reason for the global call for myopia control. Consequently, myopia in the 21st century is not only treated as a refractive error but an ocular disorder with potential negative consequences. Myopia control strategies include optical, pharmacological and behavioural methods. In this report, the effectiveness of optical methods of myopia control was reviewed. Aim: The aim of the review is to evaluate and summarise existing knowledge on myopia control and provide recommendations to guide future studies. Method: The review was conducted using online search engines including PubMed and Google Scholar. Articles published between 2000 and 2019 were included. Results: For the optical methods of myopia control, under-correction has been found to be largely ineffective. However, a recent study shows that myopic children without correction had slower myopia progression (−0.75 D) than fully corrected children (−1.04 D) indicating a 28% reduction. Evidence from various studies indicates that bifocals and progressive addition lenses are not as effective as soft dual focus contact lenses or extended depth of focus contact lenses. Clinical trials indicate that single vision rigid gas permeable lenses did not slow myopic progression. Peripheral defocus lenses and orthokeratology were found to be approximately 50% effective across studies reviewed. Conclusion: Peripheral defocus lenses and multifocal contact lens designs offer the most effective myopia control. Orthokeratology is equally effective but future designs should consider ways of minimising risks of complications with lens wear. More studies would be needed to better understand how under-corrected myopic eyes tend to progress faster, whereas myopic eyes without correction tend to progress slower. A holistic approach and combination of methods may offer the best form of myopia control in the 21st century considering the increase in near work activities and use of digital devices among the most vulnerable groups.

Background: Visual impairment among school children is relatively common and research provides evidence for integration of comprehensive eye care into school health programmes. Aim: To determine the prevalence and determinants of visual impairment in school-aged children in Southern Nigeria. Setting: School aged children from 10 public and private-owned schools in Cross River State, Southern Nigeria. Methods: This cross-sectional analytic study used a multistage random sampling technique to select 2418 school children aged 6–17 years. Comprehensive eye examinations were performed on the study. The logistic regression analysis with 95% confidence interval (CI) was used to test hypotheses. Results: Of the 2418 school children selected, 2110 (87%) were assessed. The prevalence ‘of uncorrected, presenting and best corrected visual acuity of 0.3 (20/40) or worse in the better eye’ was 7.3%, 7.2% and 0.19%, respectively. Errors of refraction were the cause of the impairment in 198 (70.7%; 63.5–76.0) eyes with reduced vision, followed by glaucoma suspects 38 (19.2%; 13.8–24.8), amblyopia (3.0%; 1.1–6.4) and corneal opacity 3 (1.5%; 0.3–4.3). The major and independent predictors of visual impairment were age (adjusted odds ratio [AOR] 1.97, 95% 1.45–2.67), high socio-economic status (adjusted odds ratio [AOR] 1.68, 95% 1.36–2.09) and female gender (AOR 1.35, 95% 1.00–1.88). Conclusion: The common causes of visual impairment in school-aged children are avoidable, and are mostly because of uncorrected refractive error, which could reflect inadequate refractive error services in the area.

ObjectiveTo estimate the effect of providing free spectacles on uncorrected visual acuity (VA) among urban migrant Chinese school children.DesignExploratory analysis from a parallel cluster-randomised clinical trial.MethodsAfter baseline survey and VA screening, eligible children were randomised by school to receive one of the two interventions: free glasses and a teacher incentive (tablet computer if ≥80% of children given glasses were wearing them on un-announced examination) (treatment group) or glasses prescription and letter to parents (control group). The primary outcome was uncorrected logarithm of the minimal angle of resolution (LogMAR) VA at study closeout, adjusted for baseline uncorrected VA.ResultsAmong 4376 randomly selected children, 728 (16.6%, mean age 10.9 years, 51.0% boys) at 94 schools failed VA screening and met eligibility criteria. Of these, 358 children (49.2%) at 47 schools were randomised to treatment and 370 children (50.8%) at 47 schools to control. Among these, 679 children (93.3%) completed follow-up and underwent analysis. Spectacle wear in the treatment and control groups was 68.3% and 29.3% (pConclusionWe found no evidence that spectacles wear worsens children’s uncorrected VA among urban migrant Chinese school children.

Background Uncorrected refractive error (URE) is a major cause of vision impairment among children that impacts negatively on their lives including distresses. We aim to understand the disability-related distress among vision-impaired children due to URE in rural and semi-rural South Africa using qualitative techniques. Methods Structured focus groups of children (aged 5-12 years old) with normal vision and vision impairment due to URE from four schools in Pinetown, KwaZulu Natal, South Africa, were performed (four mixed-gender group discussions and eight single gender group discussions). We recruited the study participants after the children underwent standardised vision screening. Criterion sampling was used when selecting study participants. The interviews were transcribed to identify meaning units and broken down to condensed meaning units, which were then grouped into megathemes. Themes were then generated. Results Thirteen children with normal vision and 63 children with vision impairment due to URE participated in the twelve focus group discussions with 36 boys (47%) and 40 girls (53%). Twelve themes were generated. The megathemes were Loss of Self Confidence (number of themes (n) = 3), Loss of self-worth (n = 3), Loss of interconnection/ interaction with community (n = 2), Humiliation (n = 2) and Discrimination (n = 2). Conclusions We found that vision impairment due to URE can cause distress in different domains in children's life and further grouped them into different themes. The themes will be used for the development of a tool to assess disability-related distress among children with vision impairment due to URE. We also recommend that distresses caused by URE should be taken into consideration when designing eye care programmes for children.

Background: Oral rehydration solution (ORS) is a form of oral rehydration therapy (ORT) for diarrhoea that has the potential to drastically reduce child mortality; yet, according to UNICEF estimates, less than half of children younger than 5 years with diarrhoea in low-income and middle-income countries (LMICs) received ORS in 2016. A variety of recommended home fluids (RHF) exist as alternative forms of ORT; however, it is unclear whether RHF prevent child mortality. Previous studies have shown considerable variation between countries in ORS and RHF use, but subnational variation is unknown. This study aims to produce high-resolution geospatial estimates of relative and absolute coverage of ORS, RHF, and ORT (use of either ORS or RHF) in LMICs. Methods: We used a Bayesian geostatistical model including 15 spatial covariates and data from 385 household surveys across 94 LMICs to estimate annual proportions of children younger than 5 years of age with diarrhoea who received ORS or RHF (or both) on continuous continent-wide surfaces in 2000-17, and aggregated results to policy-relevant administrative units. Additionally, we analysed geographical inequality in coverage across administrative units and estimated the number of diarrhoeal deaths averted by increased coverage over the study period. Uncertainty in the mean coverage estimates was calculated by taking 250 draws from the posterior joint distribution of the model and creating uncertainty intervals (UIs) with the 2·5th and 97·5th percentiles of those 250 draws. Findings: While ORS use among children with diarrhoea increased in some countries from 2000 to 2017, coverage remained below 50% in the majority (62·6%; 12 417 of 19 823) of second administrative-level units and an estimated 6 519 000 children (95% UI 5 254 000-7 733 000) with diarrhoea were not treated with any form of ORT in 2017. Increases in ORS use corresponded with declines in RHF in many locations, resulting in relatively constant overall ORT coverage from 2000 to 2017. Although ORS was uniformly distributed subnationally in some countries, within-country geographical inequalities persisted in others; 11 countries had at least a 50% difference in one of their units compared with the country mean. Increases in ORS use over time were correlated with declines in RHF use and in diarrhoeal mortality in many locations, and an estimated 52 230 diarrhoeal deaths (36 910-68 860) were averted by scaling up of ORS coverage between 2000 and 2017. Finally, we identified key subnational areas in Colombia, Nigeria, and Sudan as examples of where diarrhoeal mortality remains higher than average, while ORS coverage remains lower than average. Interpretation: To our knowledge, this study is the first to produce and map subnational estimates of ORS, RHF, and ORT coverage and attributable child diarrhoeal deaths across LMICs from 2000 to 2017, allowing for tracking progress over time. Our novel results, combined with detailed subnational estimates of diarrhoeal morbidity and mortality, can support subnational needs assessments aimed at furthering policy makers' understanding of within-country disparities. Over 50 years after the discovery that led to this simple, cheap, and life-saving therapy, large gains in reducing mortality could still be made by reducing geographical inequalities in ORS coverage. This work was primarily supported by a grant from the Bill & Melinda Gates Foundation (OPP1132415). L G Abreu has received support from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Finance Code 001), Conselho Nacional de Desenvolvimento Científico e Tecnológico and Fundação de Amparo à Pesquisa do Estado de Minas Gerais. O O Adetokunboh acknowledges the South African Department of Science and Innovation and the National Research Foundation. S M Aljunid acknowledges the Department of Health Policy and Management, Faculty of Public Health, Kuwait University and International Centre for Casemix and Clinical Coding, Faculty of Medicine, National University of Malaysia for the approval and support to participate in this research project. H T Atalay acknowledges Aksum University. M Ausloos and C Herteliu are partially supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CNDS-UEFISCDI, project number PN-III-P4-ID-PCCF-2016-0084. P S Azzopardi was supported by an Australian National Health and Medical Research Council (NHMRC) early career fellowship. A Badawi is supported by the Public Health Agency of Canada. T W Bärnighausen was supported by the Alexander von Humboldt Foundation through the Alexander von Humboldt Professor award, funded by the German Federal Ministry of Education and Research; the EU; the Wellcome Trust; and from National Institute of Child Health and Human Development of National Institutes of Health (NIH; R01-HD084233), National Institute on Aging of NIH (P01-AG041710), National Institute of Allergy and Infectious Diseases of NIH (R01-AI124389 and R01-AI112339), as well as Fogarty International Center of NIH (D43-TW009775). G B Britton is supported by Sistema Nacional de Investigación (SNI) de la Secretaría Nacional de Ciencia, Tecnología e Innovación (SENACYT) of Panamá. A Barac is funded by the Project of Ministry of Education, Science and Technology of the Republic of Serbia (number III45005). D A Bennett was supported by the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre. The views expressed are those of the authors and not necessarily those of the National Health Service, the NIHR, or the UK Department of Health and Social Care. V M Costa acknowledges her grant (SFRH/BHD/110001/2015), received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006. F Carvalho acknowledges UID/MULTI/04378/2019 and UID/QUI/50006/2019 support with funding from FCT/Ministério da Ciência, Tecnologia e Ensino Superior through national funds. K Deribe is supported by a Wellcome Trust grant (number 201900/Z/16/Z) as part of his International Intermediate Fellowship. C Herteliu is partially supported by a grant co-funded by European Fund for Regional Development through the Operational Program for Competitiveness (project ID P_40_382). P Hoogar thanks Centre for Bio Cultural Studies, Directorate of Research, Manipal Academy of Higher Education, Manipal and Centre for Holistic Development and Research, Kalaghatgi-Karnataka. S M S Islam is funded by a Fellowship from National Heart Foundation of Australia and Deakin University. M Jakovljevic and the Serbian part of this GBD contribution was co-funded through grant OI175014 of the Ministry of Education Science and Technological Development of the Republic of Serbia. A P Kengne is supported by the South African Medical Research Council. Y J Kim's work was supported by the Research Management Centre, Xiamen University Malaysia, grants number XMUMRF/2018-C2/ITCM/0001. K Krishan is supported by a DST PURSE grant and UGC Center of Advanced Study awarded to the Department of Anthropology, Panjab University, Chandigarh, India. M Kumar acknowledges K43 TW010716-03. B Lacey acknowledges support from the NIHR Oxford Biomedical Research Centre and the British Heart Foundation Centre of Research Excellence, Oxford. P T N Memiah acknowledges the Council for the Development of Social Science Research in Africa. M Molokhia is supported by the NIHR Biomedical Research Center at Guy's and St Thomas' National Health Service Foundation Trust and King's College London. I Moreno Velásquez is supported by the Sistema Nacional de Investigación (SENACYT, Panamá). G C Patton is funded by an NHMRC Fellowship. A M Samy received a fellowship from the Egyptian Fulbright Mission programme. M M Santric-Milicevic acknowledges the support of the Ministry of Education, Science and Technological Development of the Republic of Serbia (contract number 175087). A Sheikh acknowledges the support of Health Data Research UK. M R Sobhiyeh acknowledges the Clinical Research Development Center of Imam Reza Hospital, Kermanshah University of Medical Sciences for their wise advice. R Tabarés-Seisdedos was supported in part by grant PI17/00719 from Instituto de Salud Carlos III–FEDER. B Unnikrishnan acknowledges Manipal Academy of Higher Education, Manipal. M R Weaver was supported by the Bill & Melinda Gates Foundation grant OPP1127433. C S Wiysonge was supported by the South African Medical Research Council.

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.

PurposeWe used systematic review and meta-analysis to identify and assimilate evidence quantifying blindness and visual impairment (VI) associated with myopic macular degeneration (MMD), then derived models to predict global patterns. The models were used to estimate the global prevalence of blindness and VI associated with MMD from 2000 to 2050.MethodsThe systematic review identified 17 papers with prevalence data for MMD VI fitting our inclusion criteria. Data from six papers with age-specific data were scaled to relative age-dependent risk and meta-analysed at VI and blindness levels. We analysed variance in all MMD VI and blindness data as a proportion of high myopia against variables from the place and year of data collection, with a model based on health expenditure providing the best correlation. We used this model to estimate the prevalence and number of people with MMD VI in each country in each decade.ResultsWe included data from 17 studies comprising 137 514 participants. We estimated 10.0 million people had VI from MMD in 2015 (prevalence 0.13%, 95% CI 5.5 to 23.7 million, 0.07% to 0.34%), 3.3 million of whom were blind (0.04%, 1.8 to 7.8 million, 0.03% to 0.10%). We estimate that by 2050, without changing current interventions, VI from MMD will grow to 55.7 million people (0.57%, 29.0 to 119.7 million, 0.33% to 1.11%), 18.5 million of whom will be blind (0.19%, 9.6 to 39.7 million, 0.11% to 0.37%).ConclusionThe burden of MMD blindness and VI will rise significantly without efforts to reduce the development and progression of myopia and improve the management of MMD.

Background The aim was to investigate the relationship of the magnitude of myopia with visual acuity in highly myopic eyes without ocular pathology. Methods Twelve hundred and ninety-two highly myopic eyes (up to −6.00 DS both eyes, no astigmatic cut-off) with no ocular pathology from the ZOC-BHVI high myopia study in China, had cycloplegic refraction, followed by subjective refraction and visual acuities and axial length measurement. Two logistic regression models were undertaken to test the association of age, gender, refractive error, axial length and parental myopia with reduced vision. Results Mean group age was 19.0 ± 8.6 years; subjective spherical equivalent refractive error was −9.03 ± 2.73 D; objective spherical equivalent refractive error was −8.90 ± 2.60 D and axial length was 27.0 ± 1.3 mm. Using visual acuity, 82.4 per cent had normal vision, 16.0 per cent had mildly reduced vision, 1.2 per cent had moderately reduced vision, 0.3 per cent had severely reduced vision and no subjects were blind. The percentage with reduced vision increased with spherical equivalent to 74.5 per cent from −15.00 to −39.99 D, axial length to 67.7 per cent of eyes from 30.01 to 32.00 mm and age to 22.9 per cent of those 41 years and over. Spherical equivalent and axial length were significantly associated with reduced vision (p

In South Africa, primary eye care is largely challenged in its organisational structure, availability of human and other resources, and clinical competency. These do meet the standard required by the National Department of Health. This study seeks to assess the levels of knowledge, attitudes, and practices on eye health amongst Human Resources for eye health (HReH) and their managers, as no study has assessed this previously. A cross-sectional study was conducted in 11 districts of a South African province. A total of 101 participants completed self-administered, close-ended, Likert-scaled questionnaires anonymously. Binary logistic regression analysis was conducted, and values of p < 0.05 were considered statistically significant. Most participants had adequate knowledge (81.6%), positive attitudes (69%), and satisfactory practices (73%) in eye health. HReH showed better knowledge than their managers (p < 0.01). Participants with a university degree, those aged 30–44 years, and those employed for p < 0.05) towards their work. Managers, who supervise and plan for eye health, were 99% less likely to practice adequately in eye health when compared with HReH (aOR = 0.012; p < 0.01). Practices in eye health were best amongst participants with an undergraduate degree, those aged 30–44 years (aOR = 2.603; p < 0.05), and participants with p < 0.01). Knowledge, attitudes, and practices were found to be significantly moderately correlated with each other (p < 0.05). Eye health managers have poorer knowledge and practices of eye health than the HReH. A lack of direction is presented by the lack of adequately trained directorates for eye health. It is therefore recommended that policymakers review appointment requirements to ensure that adequately trained and qualified directorates be appointed to manage eye health in each district.

Importance Nearly half of children suffering vision impairment reside in China with myopia accounting for the vast majority. Background To describe the design and methodology of the Shanghai Child and Adolescent Large-scale Eye Study (SCALE). Design The SCALE was a city wide, school-based, prospective survey. Participants Children and adolescents aged 4 to 14 years from kindergarten (middle and senior), primary schools and junior high schools of all 17 districts and counties of the city of Shanghai, China were examined in 2012-2013. Methods Each enrolled child underwent vision assessment (distance visual acuity; uncorrected and with corrective device if worn) and their parent/carer completed a questionnaire designed to elicit risk factors associated with myopia. Additionally, non-cycloplegic autorefraction and ocular axial length was measured in a sub-set of the larger sample.. Main Outcome Measures Prevalence and the associated factors of vision impairment, myopia and high myopia in Shanghai. Results In 2012-2013, a total of 910,245 of the eligible 1,196,763 children and adolescents identified from census (76%, mean age 9.0 ± 2.7 years (4- 14 years)) were enrolled with visual acuity screened in the city of Shanghai. Of these, 610,952 children (67% of the entire sample) underwent non-cycloplegic autorefraction and 219,188 (24% of the entire sample) had both non-cycloplegic autorefraction and axial length measurements. Conclusions and Relevance The study results will provide insights on the burden of vision impairment, myopia and high myopia in children and adolescents in a metropolitan area of China, and contribute to the policies and strategies to address and limit the burden.

Background: The optometry training programme started in Nepal in 1997 with an intake of six students per year. The second optometry school was established in 2018 with an intake of 40 students per year. Aim: To establish a profile for Nepalese optometrists and understand their perspectives regarding the entrance examination, curriculum, infrastructure and recruitment of lecturers for a newly opened second optometry school. Setting: The prospective study respondents were contacted by email and the survey was administered online. Methods: A semi-structured questionnaire was emailed to 118 registered optometrists of the Nepalese Association of Optometrists, and the response rate of the survey was 69%. The questionnaire contained broad areas such as demographics of participants, their scope of practice, mode of entrance examination and content of the course curriculum, and availability of adequate infrastructure and lecturers. Results: A vast majority (93%) of the respondents suggested that optometrists should have been involved more in the planning of the programme. Over half of the respondents (57.5%) suggested that the programme should go ahead with a revised curriculum and well-equipped laboratories. The qualitative analysis produced four broad themes: (1) quality assurance and control; (2) resources; (3) curriculum development and implementation; and (4) professional standards and opportunities. The responders expressed several strategies to address these concerns, including communicating with stakeholders and filing a case in the court for starting up a new optometry school without sufficient involvement of the existing optometrists. Conclusion: The recommendations for improvement include conducting impartial entrance examinations, establishing equipped laboratories and recruiting adequate lecturers.

Background: Uncorrected refractive error could negatively affect learning and academic performance, there is still inadequate information for planning school health. Aim: To determine the proportion of students with vision impairment because of uncorrected refractive error, and prevalent types among learners aged 10–18 years. Setting: The study site included two of 18 local government areas of the Cross River State in Nigeria, with 23 public and mission secondary schools. Methods: A two-stage cluster sampling method was used to enrol 4241 study participants from eight selected secondary schools. Results: The prevalence of vision impairment (presenting visual acuity worse than 6/12) was 7.9% (95% confidence interval [CI]: 7.17% – 8.6%). The prevalence of vision impairment because of refractive error was 7.2% (95% CI: 6.41% – 7.96%) in the better eye. Astigmatism was the predominant type of refractive error with a prevalence of 4.2% (95% CI: 3.6% – 4.8%), followed by myopia (1.72%; 95% CI: 1.3% – 2.1%) and hyperopia (1.3%; 95% CI: 0.9% – 1.6%). There were statistically significant differences in proportions of female participants who presented with myopic astigmatism (30.8%; p < 0.012). Statistically significant difference in proportions was found in older (33.3%; p < 0.0004) and male (29.6%; p < 0.0003) participants who presented with hyperopic astigmatism compared to younger and female participants, respectively. Myopia accounted for 4.8% (95% CI: 4.2% – 5.5%) and was significantly higher in female participants (5.5%; p < 0.033). Conclusion: Refractive error was the major cause of vision impairment and myopic astigmatism was the predominant type of refractive error among secondary school children in Calabar.

The evidence-basis based on existing myopia control trials along with the supporting academic literature were reviewed; this informed recommendations on the outcomes suggested from clinical trials aimed at slowing myopia progression to show the effectiveness of treatments and the impact on patients. These outcomes were classified as primary (refractive error and/or axial length), secondary (patient reported outcomes and treatment compliance), and exploratory (peripheral refraction, accommodative changes, ocular alignment, pupil size, outdoor activity/lighting levels, anterior and posterior segment imaging, and tissue biomechanics). The currently available instrumentation, which the literature has shown to best achieve the primary and secondary outcomes, was reviewed and critiqued. Issues relating to study design and patient selection were also identified. These findings and consensus from the International Myopia Institute members led to final recommendations to inform future instrumentation development and to guide clinical trial protocols.

BackgroundTo assess prevalence and causes of vision loss in Central and South Asia.MethodsA systematic review of medical literature assessed the prevalence of blindness (presenting visual acuityResultsIn Central and South Asia combined, age-standardised prevalences of blindness, MSVI and MVI in 2015 were for men and women aged 50+years, 3.72% (80% uncertainty interval (UI): 1.39–6.75) and 4.00% (80% UI: 1.41–7.39), 16.33% (80% UI: 8.55–25.47) and 17.65% (80% UI: 9.00–27.62), 11.70% (80% UI: 4.70–20.32) and 12.25% (80% UI:4.86–21.30), respectively, with a significant decrease in the study period for both gender. In South Asia in 2015, 11.76 million individuals (32.65% of the global blindness figure) were blind and 61.19 million individuals (28.3% of the global total) had MSVI. From 1990 to 2015, cataract (accounting for 36.58% of all cases with blindness in 2015) was the most common cause of blindness, followed by undercorrected refractive error (36.43%), glaucoma (5.81%), age-related macular degeneration (2.44%), corneal diseases (2.43%), diabetic retinopathy (0.16%) and trachoma (0.04%). For MSVI in South Asia 2015, most common causes were undercorrected refractive error (accounting for 66.39% of all cases with MSVI), followed by cataract (23.62%), age-related macular degeneration (1.31%) and glaucoma (1.09%).ConclusionsOne-third of the global blind resided in South Asia in 2015, although the age-standardised prevalence of blindness and MSVI decreased significantly between 1990 and 2015.

The global prevalence of blindness and vision impairment due to uncorrected refractive error amplifies the need for the delivery of refractive services. Effective strategies need to be employed in order to ensure that they leave an impression on the landscape of refractive error blindness and vision impairment. The approaches must be systematic and evidence-based. Recent studies which plot the refractive error challenges impress upon practitioners across the eye health gamut the need to effect change immediately in an effective, sustainable and equitable manner.

OBJECTIVE To estimate global and regional trends from 1990 to 2010 of the prevalence and number of persons visually impaired specifically by diabetic retinopathy (DR), as a complication of the precipitous trends in global diabetes, is fundamental for health planning purposes. RESEARCH DESIGN AND METHODS The meta-analysis of published population studies from 1990 to 2012 for the Global Burden of Disease Study 2010 (GBD) yielded estimated global regional trends in DR among other causes of moderate and severe vision impairment (MSVI; presenting visual acuity RESULTS Globally in 2010, out of overall 32.4 million blind and 191 million visually impaired people, 0.8 million were blind and 3.7 million were visually impaired because of DR, with an alarming increase of 27% and 64%, respectively, spanning the two decades from 1990 to 2010. DR accounted for 2.6% of all blindness in 2010 and 1.9% of all MSVI worldwide, increasing from 2.1% and 1.3%, respectively, in 1990. These figures were lower in regions with younger populations (4%). CONCLUSIONS The number of persons with visual impairment due to DR worldwide is rising and represents an increasing proportion of all blindness/MSVI causes. Age-standardized prevalence of DR-related blindness/MSVI was higher in sub-Saharan Africa and South Asia. One out of 39 blind people had blindness due to DR, and 1 out of 52 visually impaired people had visual impairment due to DR.

Population-based studies involving refractive error in South Africa are few because they are expensive to conduct and require a high level of expertise. Rapid assessment of refractive error (RARE) is a relatively less resource-intensive method designed to assess the magnitude of uncorrected refractive error (URE), spectacle coverage and barriers to access of services. This information is useful for designing and implementing programs as well as for policy development.The purpose of this study was to determine the prevalence of uncorrected refractive error and spectacle coverage and to explore the barriers to uptake of refractive services in persons 15 to 35 years old in the eThekwini municipality, Durban, South Africa.A cross-sectional epidemiological study was conducted using the RARE protocol. A total of 1,543 participants were enumerated and 1,516 were examined. Uncorrected refractive error was defined as presenting visual acuity less than 6/12 that could be corrected to 6/12 or better using a pinhole. Spectacle coverage was defined as the proportion of need that was already met with spectacle correction.The prevalence of age and sex adjusted URE was 1.5% (95 per cent CI: 0.7 -2.3). Odds for uncorrected refractive error in women were 0.5 (95 per cent CI: 0.3-0.9) lower compared to men. There was a statistically significant association between uncorrected refractive error and respondents 15 to 24 years old (p 0.001). The spectacle coverage (6/12 cut-off) was 51.4 per cent (95 per cent CI: 28.1-74.7). The prevalence of spectacle use among participants was 3.8 per cent.The low prevalence of uncorrected refractive error found in this study agrees with previous studies that indicate that despite uncorrected refractive error being the most common cause of visual impairment and the second most common cause of blindness worldwide, its prevalence is relatively low in South Africans.