The impact of spectacle correction on the well-being of children with vision impairment due to uncorrected refractive error: a systematic review.

BACKGROUND: Despite being easily corrected with eyeglasses, over two-thirds of the world's child population presents with vision impairment (VI) due to uncorrected refractive errors. While systematic reviews have shown that VI can significantly impact children's depression and anxiety, none have reviewed the existing literature on the association between spectacle correction and well-being. This review aims to address this knowledge gap. MAIN OUTCOME MEASURES: The main outcome measures were i) cognitive and education well-being which included mathematics and english literacy, reading fluency, school function, academic performance and grades; ii) psychological and mental health well-being which included physical anxiety, learning anxiety and mental health test scores and iii) quality of life. METHODS: We searched eight databases for articles published between 1999 to 2021 that assessed the associations between spectacle correction and children's (0 to 18 years) well-being. There were no restrictions on language or geographic location. Two reviewers independently screened all publications using validated quality checklists. The findings of the review were analysed using narrative synthesis. [PROSPERO CRD42020196847]. RESULTS: Of 692 records found in the databases, six randomised control trials, one cohort, one cross-sectional and one qualitative study (N = 9, 1.3%) were eligible for analysis. Data were collected from 25 522 children, 20 parents and 25 teachers across the nine studies. Seven were rated as good quality (67 to 100% of quality criteria fulfilled), and two were satisfactory (33 to 66% of quality criteria fulfilled). Spectacle correction was found to improve children's educational well-being (n = 4 very strong evidence; n = 2 strong evidence), quality of life (n = 1, very strong evidence) and decrease anxiety and increase mental health scores (n = 1, strong evidence). CONCLUSION: Evidence suggests that spectacle correction improves children's cognitive and educational well-being, psychological well-being, mental health, and quality of life. More research is needed, given the paucity of published literature and the focus on only three aspects of well-being.

Profiling and factors associated with glaucoma diagnostic practice in sub-Saharan Africa-a cross sectional study of Nigerian and Ghanaian optometrists.

BACKGROUND: Ghana and Nigeria are the two countries in Africa that currently run the Doctor of Optometry (OD) program in sub-Saharan Africa (SSA). Optometrists in these countries are licensed to provide glaucoma care. Despite the clinically relevant practice guidelines for glaucoma, there is no data on the practice patterns for glaucoma eye care in SSA, a region with the highest prevalence of glaucoma. This study aimed to profile glaucoma diagnosis adherence to practice guidelines among optometrists in two neighbouring anglophone countries (Nigeria and Ghana). METHODS: A web-based cross-sectional survey of practising optometrists was conducted in both countries. Each country data was weighted to reflect the total number of licensed and practising optometrists at the time of this survey. Descriptive analyses were performed against demography and practice factors using survey commands to adjust for sampling weights when estimating confidence intervals (CI) around prevalence estimates. Simple and multiple logistic regression analyses were performed to identify factors associated with glaucoma diagnosis. RESULTS: A total of 493 optometrists (238, 48.3% and 255, 51.7%) from Ghana and Nigeria respectively, responded to the survey-the first to document and compare the glaucoma diagnostic criteria between optometrists in Ghana and Nigeria. More Ghanaian than Nigerian optometrists diagnosed glaucoma and over 90% in both countries reported that they frequently performed either tonometry, visual field testing, or fundus examination during glaucoma diagnosis. Ghanaian optometrists were significantly more likely to diagnose glaucoma than Nigerian optometrists (adjusted odd ratio, AOR = 6.15, 95%CI:1.63-23.15, P = .007). Optometrists who have practiced for more than 10 years (AOR = 7.04; 95%CI:1.74-28.47, P = .006) and private practice optometrists (AOR = 3.33; 95%CI:1.13-9.83, P = .03) were more likely to diagnose glaucoma. CONCLUSIONS: The study provides information for evaluating glaucoma assessment for optometrists in both countries. Optometrists in both countries are reasonably well-equipped to diagnose glaucoma and are practicing at an adequate level, but with room for improvement.

Trends in myopia management attitudes and strategies in clinical practice: Survey of eye care practitioners in Africa.

PURPOSE: There remains a lack of information on the perception and adoption of myopia control strategies among African eye care practitioners (ECPs). This study provides an African perspective to similar previous studies conducted in other parts of the world. METHODS: A self-administered survey in English and French was distributed to ECPs across Africa. The items on the questionnaire assessed their level of concern about the increasing prevalence of paediatric myopia, perceived efficacy, opinions on, and adoption of various myopia management modalities. RESULTS: Responses were obtained from 330 ECPs working in 23 African countries. Respondents were highly concerned about the increasing prevalence of paediatric myopia in their clinic (median 8/10) and perceived approved myopia control soft contact lenses as the most effective at slowing myopia progression (mean perceived reduction in myopia progression ± SD; 53.9 ± 27.1%), followed by single vision spectacles (53.1 ± 30.9%), and orthokeratology (52.8 ± 28.0%). Multifocal soft contact lenses (40.4 ± 25.8%) and pharmaceutical agents such as topical atropine drops (39.5 ± 27.1%) were perceived as least effective in slowing myopia progression. Although ECPs reported being aware of various myopia control strategies, they still mainly prescribed single vision spectacles to a large proportion (64.3 ± 29.9%) of young progressing myopes. Nearly one-third (27%) of ECPs who prescribed single vision lenses stated they were concerned about the cost implications to patients. Other reported concerns included safety of, and inadequate information about myopia control options. CONCLUSIONS: African ECPs continue to prescribe single vision lenses for progressing myopes despite being aware of the various myopia control options. Practitioners' perceptions of the efficacy of several modalities to slow myopia progression do not align with the current best evidence. Clear practice guidelines and continuing education on myopia control are warranted to inform and guide the management of myopic patients in Africa.

Effective refractive error coverage in adults aged 50 years and older: estimates from population-based surveys in 61 countries.

BACKGROUND: In 2021, WHO Member States endorsed a global target of a 40-percentage-point increase in effective refractive error coverage (eREC; with a 6/12 visual acuity threshold) by 2030. This study models global and regional estimates of eREC as a baseline for the WHO initiative. METHODS: The Vision Loss Expert Group analysed data from 565 448 participants of 169 population-based eye surveys conducted since 2000 to calculate eREC (met need/[met need + undermet need + unmet need]). A binary logistic regression model was used to estimate eREC by Global Burden of Disease (GBD) Study super region among adults aged 50 years and older. FINDINGS: In 2021, distance eREC was 79·1% (95% CI 72·4-85·0) in the high-income super region; 62·1% (54·7-68·8) in north Africa and Middle East; 49·5% (45·0-54·0) in central Europe, eastern Europe, and central Asia; 40·0% (31·7-48·2) in southeast Asia, east Asia, and Oceania; 34·5% (29·4-40·0) in Latin America and the Caribbean; 9·0% (6·5-12·0) in south Asia; and 5·7% (3·1-9·0) in sub-Saharan Africa. eREC was higher in men and reduced with increasing age. Global distance eREC increased from 2000 to 2021 by 19·0%. Global near vision eREC for 2021 was 20·5% (95% CI 17·8-24·4). INTERPRETATION: Over the past 20 years, distance eREC has increased in each super region yet the WHO target will require substantial improvements in quantity and quality of refractive services in particular for near vision impairment. FUNDING: WHO, Sightsavers, The Fred Hollows Foundation, Fondation Thea, Brien Holden Vision Institute, Lions Clubs International Foundation.

Influence of Distance and Near Visual Impairment on Self-Reported Near Visual Functioning in a Multinational Study.

PURPOSE: To assess the influence of distance and near visual impairment on self-reported near visual functioning (VF) in a multinational study. DESIGN: Population-based cross-sectional study. PARTICIPANTS: Participants aged 35 years or older were selected randomly with cluster sampling at 7 sites: rural sites in Nepal (Kaski) and India (Madurai), a semirural site in China (Shunyi), semiurban 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 logarithm of the minimum angle of resolution tumbling E chart at 4 m 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: Visual functioning subscale scores. RESULTS: The study sample consisted of 6851 questionnaire respondents. The VF subscale scores decreased significantly with worse distance and near VA, and even mildly impaired VA could result in reduced VF. Lower VF subscale scores were associated with older age at 4 sites, female gender at 3 sites, and greater education at 2 sites. The influence of near VA was greater than distance VA at 3 sites, and at 1 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 with 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 were found in Guangzhou and Madurai; and 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 socioeconomic and cultural settings.

Potential Lost Productivity Resulting from the Global Burden of Myopia: Systematic Review, Meta-analysis, and Modeling.

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.

Building consensus for the development of child eye care services in South Darfur State of Sudan using the Delphi technique.

BACKGROUND:  Global estimates suggest there are almost 19 million visually impaired children worldwide, most of whom reside in poor countries, with the major cause being treatable. AIM:  To determine the barriers to accessing childhood eye care services and to develop an eye care plan for children in South Darfur State, Sudan. SETTING:  The study took place in South Darfur State, Sudan. METHODS:  The classical Delphi technique was used to build consensus on a list of statements, which were generated based on the themes established by the experts, as well as on an extensive literature review. RESULTS:  Response rates ranged from 90% in the first round (n = 18), 100% in the second round (n = 18) to 89% in the third and final round (n = 16). The total number of statements recommended by the Delphi panellists for development of the paediatric eye care plan, was 60 based on a consensus level of 80% agreement or more. The expert's consensus on the following key elements for promotion and improvement of child eye care: The main barriers to accessing child eye care were high poverty rate, unavailability of child eye services and a lack of community awareness. The challenges facing visually impaired children were an absence of paediatric ophthalmologists, low vision and orthoptic services. CONCLUSION:  The main barriers to accessing child eye care services were financial, clinical access and lack of knowledge. There should be greater collaboration between the Ministries of Health, Education and non-governmental organisations (NGOs), to work together in addressing these barriers.

Global Prevalence of Presbyopia and Vision Impairment from Uncorrected Presbyopia: Systematic Review, Meta-analysis, and Modelling.

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.

Global prevalence of visual impairment associated with myopic macular degeneration and temporal trends from 2000 through 2050: systematic review, meta-analysis and modelling.

PURPOSE: We 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. METHODS: The 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. RESULTS: We 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%). CONCLUSION: The 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.

Rapid assessment of refractive error in the eThekwini Municipality of KwaZulu-Natal, Durban, South Africa.

BACKGROUND: 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. PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Global Vision Impairment and Blindness Due to Uncorrected Refractive Error, 1990-2010.

The purpose of this systematic review was to estimate worldwide the number of people with moderate and severe visual impairment (MSVI; presenting visual acuity <6/18, ≥3/60) or blindness (presenting visual acuity <3/60) due to uncorrected refractive error (URE), to estimate trends in prevalence from 1990 to 2010, and to analyze regional differences. The review focuses on uncorrected refractive error which is now the most common cause of avoidable visual impairment globally. : The systematic review of 14,908 relevant manuscripts from 1990 to 2010 using Medline, Embase, and WHOLIS yielded 243 high-quality, population-based cross-sectional studies which informed a meta-analysis of trends by region. The results showed that in 2010, 6.8 million (95% confidence interval [CI]: 4.7-8.8 million) people were blind (7.9% increase from 1990) and 101.2 million (95% CI: 87.88-125.5 million) vision impaired due to URE (15% increase since 1990), while the global population increased by 30% (1990-2010). The all-age age-standardized prevalence of URE blindness decreased 33% from 0.2% (95% CI: 0.1-0.2%) in 1990 to 0.1% (95% CI: 0.1-0.1%) in 2010, whereas the prevalence of URE MSVI decreased 25% from 2.1% (95% CI: 1.6-2.4%) in 1990 to 1.5% (95% CI: 1.3-1.9%) in 2010. In 2010, URE contributed 20.9% (95% CI: 15.2-25.9%) of all blindness and 52.9% (95% CI: 47.2-57.3%) of all MSVI worldwide. The contribution of URE to all MSVI ranged from 44.2 to 48.1% in all regions except in South Asia which was at 65.4% (95% CI: 62-72%). : We conclude that in 2010, uncorrected refractive error continues as the leading cause of vision impairment and the second leading cause of blindness worldwide, affecting a total of 108 million people or 1 in 90 persons.

Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050.

PURPOSE: Myopia is a common cause of vision loss, with uncorrected myopia the leading cause of distance vision impairment globally. Individual studies show variations in the prevalence of myopia and high myopia between regions and ethnic groups, and there continues to be uncertainty regarding increasing prevalence of myopia. DESIGN: Systematic review and meta-analysis. METHODS: We performed a systematic review and meta-analysis of the prevalence of myopia and high myopia and estimated temporal trends from 2000 to 2050 using data published since 1995. The primary data were gathered into 5-year age groups from 0 to ≥100, in urban or rural populations in each country, standardized to definitions of myopia of -0.50 diopter (D) or less and of high myopia of -5.00 D or less, projected to the year 2010, then meta-analyzed within Global Burden of Disease (GBD) regions. Any urban or rural age group that lacked data in a GBD region took data from the most similar region. The prevalence data were combined with urbanization data and population data from United Nations Population Department (UNPD) to estimate the prevalence of myopia and high myopia in each country of the world. These estimates were combined with myopia change estimates over time derived from regression analysis of published evidence to project to each decade from 2000 through 2050. RESULTS: We included data from 145 studies covering 2.1 million participants. We estimated 1406 million people with myopia (22.9% of the world population; 95% confidence interval [CI], 932-1932 million [15.2%-31.5%]) and 163 million people with high myopia (2.7% of the world population; 95% CI, 86-387 million [1.4%-6.3%]) in 2000. We predict by 2050 there will be 4758 million people with myopia (49.8% of the world population; 3620-6056 million [95% CI, 43.4%-55.7%]) and 938 million people with high myopia (9.8% of the world population; 479-2104 million [95% CI, 5.7%-19.4%]). CONCLUSIONS: Myopia and high myopia estimates from 2000 to 2050 suggest significant increases in prevalences globally, with implications for planning services, including managing and preventing myopia-related ocular complications and vision loss among almost 1 billion people with high myopia.

Prevalence of Refractive Errors in the INK Area, Durban, South Africa.

PURPOSE: To determine the prevalence and types of refractive errors in persons aged 35 years and older in the Inanda, Ntuzuma, and KwaMashu (INK) area of Durban, KwaZulu-Natal Province, South Africa. METHODS: Refractive error data were obtained by autorefraction (Retinomax K-Plus; Nikon, Tokyo, Japan), retinoscopy, and subjective refraction. Refractive error was defined using spherical equivalents as myopia (<-0.5D) and hyperopia (>+0.5D). Astigmatism was defined as cylinder equal to or greater than -0.5D in either eye. RESULTS: Participants' ages ranged from 35 to 90 years, with a mean of 53.05 ± 11.4 years. Women comprised 75% of the subjects. The prevalence of refractive error was 57.3%, with myopia 11.4%, hyperopia 37.7%, and astigmatism 25.7%. Myopia and astigmatism were significantly more prevalent in men (p < 0.01), whereas hyperopia was more prevalent in women (p < 0.01). Hyperopia was significantly associated with education (p < 0.01), whereas myopia and astigmatism were not (p = 0.09 and p = 0.15, respectively). CONCLUSIONS: Approximately 57.3% of the population 35 years and older in the INK area of Durban were affected by refractive errors, with myopia, hyperopia, and astigmatism being significantly associated with sex. This study suggests that there is a need for interventions to alleviate refractive error in the INK area as well as in other communities affected by the lack of access to affordable services.

How Do Patients Choose Their Spectacles in the Public Sector of South Africa?

PURPOSE: This study was designed to understand the profiles of the patients who attended and chose to purchase spectacles from the public sector eye clinics in KwaZulu Natal, South Africa. Furthermore, we wished to explore patients' perceptions of the spectacle frames on offer and to understand the motivation of the patients in selecting their spectacle frames. METHODS: This descriptive study consented 674 patients from seven eye clinics in KwaZulu Natal. Each was interviewed using a questionnaire containing open-ended, close-ended questions and questions with a Likert-scale response. RESULTS: Females comprised 68.4% of the study population. The majority of participants had not completed secondary school or had no schooling (78.9%), were unemployed (70.9%), and earned less than R2000 per month or did not have any form of income (89.2%). Of the 670 who chose to buy spectacles from the eye clinics, 79.4% indicated that this was convenient (79.4%) and 23.0% said that they were motivated in their decision because they liked the available frames. More than 95% of participants rated the design, quality, and price as good to excellent. Factors influencing their decisions included design, recommendations from staff, and quality. Those who bought the spectacles from the budget range were prepared to pay more for the next pair of spectacles, whereas almost all reported that they would return to the same eye clinic for their next pair of spectacles and that they would recommend relatives and friends to the clinic. CONCLUSIONS: The results from the study indicate that there is high acceptance by patients of the range of spectacles offered in public sector eye clinics with specific suggestions to improve it. Increased understanding of the perceptions and motivations in spectacle choice will help inform planning and procurement decisions in supplying the needs of the patients and broadening the patient base.

Population Prevalence of Need for Spectacles and Spectacle Ownership Among Urban Migrant Children in Eastern China.

IMPORTANCE: The number of urban migrants in China is 300 million and is increasing rapidly in response to government policies. Urban migrants have poor access to health care, but little is known about rates of correction of refractive error among migrant children. This is of particular significance in light of recent evidence demonstrating the educational impact of providing children with spectacles. OBJECTIVE: To measure prevalence of spectacle need and ownership among Chinese migrant children. DESIGN, SETTING, AND PARTICIPANTS: Population-based, cross-sectional study among children who failed vision testing (uncorrected visual acuity ≤6/12 in either eye) between September 15 and 30, 2013, at 94 randomly selected primary schools in predominantly migrant communities in Shanghai, Suzhou, and Wuxi, China. MAIN OUTCOMES AND MEASURES: Refractive error by cycloplegic refraction; spectacle ownership, defined as producing glasses at school, having been told to bring them; and needing glasses, defined as uncorrected visual acuity of 6/12 or less correctable to greater than 6/12 in either eye, with myopia of -0.5 diopters (D) or less, hyperopia of +2.0 D or greater, or astigmatism of 0.75 D or greater in both eyes. RESULTS: Among 4409 children, 4376 (99.3%) completed vision screening (mean [SD] age, 11.0 [0.81] years; 55.3% boys; 4225 [96.5%] migrant and 151 [3.5%] local). Among 1204 children failing vision testing (total, 27.5%; 1147 migrant children [27.1%] vs 57 local children [37.7%]; P = .003), 850 (70.6%) completed refraction. Spectacle ownership in migrant children needing glasses (147 of 640 children [23.0%]) was less than among local children (12 of 34 children [35.3%]) (odds ratio = 0.55; 95% CI, 0.32-0.95; P = .03). Having uncorrected visual acuity less than 6/18 in both eyes was associated positively with baseline spectacle ownership (odds ratio = 5.73; 95% CI, 3.81-8.62; P < .001), but parental education and family wealth were not. CONCLUSIONS AND RELEVANCE: Among urban migrant children, there was a high prevalence of need for spectacles and a very low rate of spectacle ownership. Spectacle distribution programs are needed specifically targeting migrant children.

The Global Burden of Potential Productivity Loss from Uncorrected Presbyopia.

PURPOSE: The onset of presbyopia in middle adulthood results in potential losses in productivity among otherwise healthy adults if uncorrected or undercorrected. The economic burden could be significant in lower-income countries, where up to 94% of cases may be uncorrected or undercorrected. This study estimates the global burden of potential productivity lost because of uncorrected functional presbyopia. DESIGN: Population data from the US Census Bureau were combined with the estimated presbyopia prevalence, age of onset, employment rate, gross domestic product (GDP) per capita in current US dollars, and near vision impairment disability weights from the Global Burden of Disease 2010 study to estimate the global loss of productivity from uncorrected and undercorrected presbyopia in each country in 2011. To allow comparison with earlier work, we also calculated the loss with the conservative assumption that the contribution to productivity extends only up to 50 years of age. PARTICIPANTS: The economic modeling did not require the use of subjects. METHODS: We estimated the number of cases of uncorrected or undercorrected presbyopia in each country among the working-age population. The number of working-age cases was multiplied by the labor force participation rate, the employment rate, a disability weight, and the GDP per capita to estimate the potential loss of GDP due to presbyopia. MAIN OUTCOME MEASURES: The outcome being measured is the lost productivity in 2011 US dollars resulting from uncorrected or undercorrected presbyopia. RESULTS: There were an estimated 1.272 billion cases of presbyopia worldwide in 2011. A total of 244 million cases, uncorrected or undercorrected among people aged <50 years, were associated with a potential productivity loss of US $11.023 billion (0.016% of global GDP). If all those people aged <65 years are assumed to be productive, the potential productivity loss would be US $25.367 billion or 0.037% of global GDP. Correcting presbyopia to the level achieved in Europe would reduce the burden to US $1.390 billion (0.002% of global GDP). CONCLUSIONS: Even with conservative assumptions regarding the productive population, presbyopia is a significant burden on productivity, and correction would have a significant impact on productivity in lower-income countries.

Visual profile of students in integrated schools in Malawi.

BACKGROUND: Blindness and visual impairment are very common in African countries and are often loosely linked to inadequate resources. We designed this study to assess clinical visual and ocular characteristics of children in three integrated schools in Malawi, so that students needing low vision services or those with correctable refractive error will be identified. METHODS: We included 95 students, who underwent a detailed optometric examination. The assessment included distance visual acuity measurement in logMAR notation, near visual acuity, oculo-motor assessment, pupillary assessment and anterior as well as posterior segment evaluation. Non-cycloplegic refraction was done in all the participants. RESULTS: Mean age of students was 13.84 ±4.61 years. Almost 90 per cent of students had presenting visual acuity worse than logMAR 0.54. Visual acuity improved significantly after refractive correction by more than two logMAR lines in 31.8 per cent (p < 0.0001). Refractive error was very common (36.5 per cent) and the most common causes of visual impairment were lenticular (21.2 per cent), corneal (20.0 per cent) and albinism (15.3 per cent). One-tenth (10.5 per cent) of the students were wrongly enrolled in the schools, even though they did not have visual impairment. The compliance to spectacles wear was very poor (37 per cent). An adequate refractive correction improved visual acuity in more than a third (36.5 per cent) of the students. Students benefited from spectacle magnifiers (18.8 per cent), handheld magnifiers (4.7 per cent) and telescopes (5.9 per cent). Mobility canes were advised for 36.5 per cent of the students. CONCLUSION: Nine out of ten students in three integrated schools in Malawi had visual impairment and 41 per cent had low vision. Inappropriate placement in the integrated schools and poor spectacle compliance are very common. Well accepted optical and non-optical devices could improve visual performance in visually disabled children, for which public awareness and parental education is important.

Prevalence of refractive error, presbyopia and spectacle coverage in Kahama District, Tanzania: a rapid assessment of refractive error.

BACKGROUND: In Tanzania, the prevalence of refractive error and presbyopia have not been comprehensively assessed, limiting appropriate planning and implementation of delivery of vision care. This study sought to determine the prevalence of refractive error and presbyopia, spectacle coverage and the barriers to uptake of refractive services in people aged 15 years and older in the Kahama district of Tanzania. METHODS: A cross-sectional community-based survey was conducted using 54 randomly selected clusters. Respondents 15 years and older were interviewed and underwent standardised clinical eye examinations. Uncorrected refractive error (URE) was defined as presenting vision worse than 6/12 that could be corrected to better than 6/12 using a pinhole. Spectacle coverage was defined as the proportion of need that was met (those that improved from unaided vision with their own spectacle correction). RESULTS: A total of 3,230 subjects (99.75 per cent of 3,240 eligible) participated in the study with 57.2 per cent males and the median age of participants was 35 years (inter-quartile range, 24 to 49). The prevalence of visual impairment was 10.4 per cent (95% CI 9.4 to 11.4) and was lower in those who had completed their primary school education (odds ratio (OR) 0.54, 95% CI: 0.40 to 0.72) and highest in subjects 40 years and older (OR 3.17, 95% CI: 2.14 to 4.70) and farmers (OR 8.57 95% CI: 2.27 to 32.43). Refractive error prevalence was 7.5 per cent (95% CI: 6.65 to 8.54) and this was highest in participants over 40 years (OR 1.60, 95% CI: 1.14 to 2.25) and in students (OR 3.64, 95% CI: 1.35 to 9.86). Prevalence of presbyopia was 46.5 per cent (773/1,663, 95% CI: 44.34 to 48.75). Spectacle coverage for refractive error and presbyopia was 1.69% (95% CI: 0 to 3.29) and 0.42% (95% CI: 0 to 1.26), respectively. CONCLUSION: Uncorrected refractive error is a public health challenge in the Kahama district and sustainable service delivery and health promotion efforts are needed.

The prevalence of self-reported vision difficulty in economically disadvantaged regions of South Africa.

BACKGROUND: Vision impairment, resulting in vision difficulties, is a leading cause of disability, and hence one of the key barriers for people to access education and employment, which may force them into poverty. OBJECTIVES: The objective of this study was to determine the prevalence of self-reported vision difficulties as an indicator of vision impairment in economically disadvantaged regions in South Africa, and to examine the relationship between self-reported vision difficulties and socio-economic markers of poverty, namely, income, education and health service needs. METHODS: A cross-sectional study was conducted in economically disadvantaged districts to collect data from households on poverty and health, including vision difficulty. As visual acuity measurements were not conducted, the researchers used the term vision difficulty as an indicator of vision impairment. Data were collected from 27 districts (74 901 respondents). Logistic regression analysis and chi-square tests were used to determine bivariate relationships between variables and self-reported vision difficulty. Kernel density estimators were used for age, categorised by self-reported and not reported vision difficulty. RESULTS: Prevalence of self-reported vision difficulty was 11.2% (95% CI, 8.7% - 13.7%). More women (12.7%) compared to men (9.5%) self-reported vision difficulty (p < 0.01). Self-reported vision difficulty was higher (14.2%) for respondents that do not spend any money. A statistically significant relationship was found between the highest level of education and self-reporting of vision difficulty; as completed highest level of education increased, self-reporting of vision difficulty became lower (p < 0.01). A significantly higher prevalence of self-reported vision difficulty was found in respondents who are employed (p < 0.01), 17% (95% CI: 12.8% - 21.1%). CONCLUSION: The evidence from this study suggests associations between socio-economic factors and vision difficulties that have a two-fold relationship (some factors such as education, and access to eye health services are associated with vision difficulty whilst vision difficulty may trap people in their current poverty or deepen their poverty status). The results are thus indicative of the need for further research in South Africa.