The burden, causes, and determinants of blindness and vision impairment in Asia: An analysis of the Global Burden of Disease Study.

Background: Asia accounts for more than half of the world's population and carries a substantial proportion of the global burden of blindness and vision impairment. Characterising this burden, as well as its causes and determinants, could help with devising targeted interventions for reducing the occurrence of blindness and visual impairment. Methods: Using the Global Burden of Disease Study 2019 database, we retrieved data on the number of disability-adjusted life years (DALYs); crude and age-standardised rates; and the prevalence (with 95% uncertainty intervals (95%UIs)) of blindness and vision loss due to six causes (age-related macular degeneration, cataracts, glaucoma, near-vision impairment, refractive error, and other vision loss) for Asian countries for the period between 1990 and 2019. We defined DALYs as the sum of the years lost due to disability and years of life lost, and calculated age-standardised figures for the number of DALYs and prevalence by adjusting for population size and age structure. We then evaluated the time trend of the disease burden and conducted subgroup analyses by gender, age, geographic locations, and socio-demographic index (SDI). Results: In 2019, the DALYs and prevalence of blindness and vision loss had risen by 90.1% and 116% compared with 1990, reaching 15.84 million DALYs (95% UI = 15.83, 15.85) and 506.71 million cases (95% UI = 506.68, 506.74). Meanwhile, the age-standardised rate of DALYs decreased from 1990 to 2019. Cataracts, refractive error, and near vision impairment were the three most common causes. South Asia had the heaviest regional disease burden (age-standardised rate of DALYs = 517 per 100 000 population; 95% UI = 512, 521). Moreover, the burden due to cataracts ranked high in most Asian populations. Being a woman; being older; and having a lower national SDI were factors associated with a greater vision loss burden. Conclusions: The burden due to vision loss remains high in Asian populations. Cataracts, refractive error, and near vision loss were the primary causes of blindness and vision loss. Greater investment in ocular disease prevention and care by countries with lower socioeconomic status is needed, as well as specific strategies targeting cataract management, women and the elderly.

The effect on income of providing near vision correction to workers in Bangladesh: The THRIVE (Tradespeople and Hand-workers Rural Initiative for a Vision-enhanced Economy) randomized controlled trial.

INTRODUCTION: Presbyopia, the leading cause of vision impairment globally, is common during working years. However, no trials have assessed presbyopia's impact on income. METHODS: In April 2017, we conducted a census among 59 Bangladesh villages to identify persons aged 35 to 65 years with presbyopia (presenting distance vision > = 6/12 bilaterally and correctable inability to see 6/13 at 40 cm with both eyes), who never had owned glasses. Participants were randomized (1:1) to receive immediate free reading glasses (intervention) or glasses delivered 8 months later (control). Visual demand of different jobs was stratified into three levels. Outcomes were between-group differences in the 8 month change in: self-reported monthly income (primary) and Near Vision Related Quality of Life (NVRQOL, secondary). RESULTS: Among 10,884 census participants, 3,655 (33.6%) met vision criteria and 863 (23.6%) comprised a sample enriched for near vision-intensive jobs, but 39 (4.52%) could not be reached. All participants allocated to intervention (n = 423, 51.3%) and control (n = 401, 48.7%) received the appropriate intervention, and follow-up was available for 93.4% and 96.8% respectively. Groups were similar at baseline in all characteristics: mean age was 47 years, 50% were male, 35% literate, and about half engaged in "most near vision-intensive" occupations. Glasses wear at 8-month follow-up was 88.3% and 7.81% in intervention and control respectively. At baseline, both the intervention and control groups had a self-reported median monthly income of US$35.3. At endline, the median income for the intervention group was US$47.1 compared with US$35.3 for control, a difference of 33.4%. Predictors of greater income increase in multivariate models included intervention group allocation (OR 1.45, 95% CI 1.12, 1.88, P = 0.005), male sex (OR 2.41, 95% CI 1.84, 3.16, P <0.001), and not engaging in income-producing work at baseline (OR 2.35, 95% CI 1.69, 3.26, P<0.001). CONCLUSION: Provision of reading glasses increases income in near vision-intensive occupations, and may facilitate return to work for those currently unemployed.

Assessment of Causality Between Diet-Derived Antioxidants and Primary Open-Angle Glaucoma: A Mendelian Randomization Study.

Purpose: This study aimed to investigate the genetic causal relationships among diet-derived circulating antioxidants, primary open-angle glaucoma (POAG), and glaucoma-related traits using two-sample Mendelian randomization (MR). Methods: Genetic variants associated with diet-derived circulating antioxidants (retinol, ascorbate, ß-carotene, lycopene, α-tocopherol, and γ-tocopherol) were assessed as absolute and metabolic instrumental variables. POAG and glaucoma-related traits data were derived from a large, recently published genome-wide association study database; these traits included intraocular pressure (IOP), macular retinal nerve fiber layer (mRNFL) thickness, macular ganglion cell-inner plexiform layer (mGCIPL) thickness, and vertical cup-to-disc ratio (vCDR). MR analyses were performed per outcome for each exposure. Results: We found no causal association between six diet-derived antioxidants and POAG using the International Glaucoma Genetics Consortium data. For absolute antioxidants, the odds ratios (ORs) ranged from 1.011 (95% confidence interval [CI], 0.854-1.199; P = 0.895) per natural log-transformed ß-carotene to 1.052 (95% CI, 0.911-1.215; P = 0.490) for 1 µmol/L of ascorbate. For antioxidant metabolites, the OR ranged from 0.998 (95% CI, 0.801-1.244; P = 0.989) for ascorbate to 1.210 (95% CI, 0.870-1.682; P = 0.257) for γ-tocopherol, using log-transformed levels. A similar result was obtained with the FinnGen Biobank. Furthermore, our results showed no significant genetic association between six diet-derived antioxidants and glaucoma-related traits. Conclusions: Our study did not support a causal association among six diet-derived circulating antioxidants, POAG, and glaucoma-related traits. This suggests that the intake of antioxidants may not have a preventive effect on POAG and offers no protection to retinal nerve cells. Translational Relevance: This study provides valid evidence regarding the use of diet-derived antioxidants for glaucoma patients.

Persistence of severe global inequalities in the burden of blindness and vision loss from 1990 to 2019: findings from the Global Burden of Disease Study 2019.

AIMS: To assess the global burden and economic inequalities in the distribution of blindness and vision loss between 1990 and 2019. METHODS: A secondary analysis of the Global Burden of Diseases, Injuries and Risk Factors Study (GBD) 2019. Data for disability-adjusted life-years (DALYs) due to blindness and vision loss were extracted from the GBD 2019. Data for gross domestic product per capita were extracted from the World Bank database. Slope index of inequality (SII) and concentration index were computed to assess absolute and relative cross-national health inequality, respectively. RESULTS: Countries with high, high-middle, middle, low-middle and low Socio-demographic Index (SDI) had decline of age-standardised DALY rate of 4.3%, 5.2%, 16.0%, 21.4% and 11.30% from 1990 to 2019, respectively. The poorest 50% of world citizens bore 59.0% and 66.2% of the burden of blindness and vision loss in 1990 and 2019, respectively. The absolute cross-national inequality (SII) fell from -303.5 (95% CI -370.8 to -236.2) in 1990 to -256.0 (95% CI -288.1 to -223.8) in 2019. The relative inequality (concentration index) for global blindness and vision loss remained essentially constant between 1991 (-0.197, 95% CI -0.234 to -0.160) and 2019 (-0.193, 95% CI -0.216 to -0.169). CONCLUSION: Though countries with middle and low-middle SDI were the most successful in decreasing burden of blindness and vision loss, a high level of cross-national health inequality persisted over the past three decades. More attention must be paid to the elimination of avoidable blindness and vision loss in low-income and middle-income countries.

Collaboration of health and education sectors drives equity for children with complex disabilities in China.

Medical professionals often find it challenging to assess children having both complex disabilities and visual impairment, which may lead to excluding such children from educational programs and limiting their full participation in family and community activities. Identification and assessment of these children are essential to close this exclusion gap. A five-year project in Shanxi province, China, provided comprehensive training to eye health providers and educators as they learned to assess, identify, refer and serve children with visual impairments, both with and without complex disabilities. A team of teachers, vision and general healthcare providers worked to assess the vision of these children at schools, residential settings, and in homes throughout Shanxi. The project led to deep collaboration between Shanxi's health and education sectors, and established replicable precedents for policy and system changes toward the inclusion of children with complex disabilities and visual impairment.

Autonomous artificial intelligence increases real-world specialist clinic productivity in a cluster-randomized trial.

Autonomous artificial intelligence (AI) promises to increase healthcare productivity, but real-world evidence is lacking. We developed a clinic productivity model to generate testable hypotheses and study design for a preregistered cluster-randomized clinical trial, in which we tested the hypothesis that a previously validated US FDA-authorized AI for diabetic eye exams increases clinic productivity (number of completed care encounters per hour per specialist physician) among patients with diabetes. Here we report that 105 clinic days are cluster randomized to either intervention (using AI diagnosis; 51 days; 494 patients) or control (not using AI diagnosis; 54 days; 499 patients). The prespecified primary endpoint is met: AI leads to 40% higher productivity (1.59 encounters/hour, 95% confidence interval [CI]: 1.37-1.80) than control (1.14 encounters/hour, 95% CI: 1.02-1.25), p < 0.00; the secondary endpoint (productivity in all patients) is also met. Autonomous AI increases healthcare system productivity, which could potentially increase access and reduce health disparities. ClinicalTrials.gov NCT05182580.

Willingness to pay for diabetic retinopathy screening in Qujiang District, rural Guangdong, southern China: a cross-sectional study.

OBJECTIVE: To determine willingness to pay for a diabetic retinopathy screening, and its determinants, among people with diabetes mellitus in Qujiang District of Shaoguan City, rural Guangdong, southern China. DESIGN: This cross-sectional study was conducted through a large-scale screening programme in 2019. We randomly selected 575 (21.5%) among 2677 people over 18 years old with known diabetes who attended the screening. Participants elected to pay nothing or RMB10-RMB120 (US$1.6-US$18.8), in RMB10 intervals, displayed on printed cards. One trained interviewer collected all the data. SETTING: Ten primary health centres in Qujiang District of Shaoguan City, Guangdong. PARTICIPANTS: 545 from the 575 randomly selected people (94.8%) agreed to participate in the study. OUTCOME MEASURES: Proportion of participants willing to pay anything for screening, mean amount they were willing to pay and determinants of these figures. RESULTS: Among 545 participants (mean age 64.6 years (SD±10.4), 40.7% men), 327 (60.0%) were willing to pay something for screening, of whom 273 (83.5%) would pay RMB10-RMB30 (US$1.6-US$4.7). People living in rural areas and those from lower-income families were more likely to be willing to pay anything, while men, urban residents and those covered by employer-linked insurance were willing to pay larger sums (p<0.05 for all). CONCLUSION: Nearly two-thirds of participants were willing to pay for screening in this screening programme organised at the primary care level in rural China. This finding offers the potential that such activities can be sustained and scaled up through user fees.

Artificial Intelligence in Community-Based Diabetic Retinopathy Telemedicine Screening in Urban China: Cost-effectiveness and Cost-Utility Analyses With Real-world Data.

BACKGROUND: Community-based telemedicine screening for diabetic retinopathy (DR) has been highly recommended worldwide. However, evidence from low- and middle-income countries (LMICs) on the choice between artificial intelligence (AI)-based and manual grading-based telemedicine screening is inadequate for policy making. OBJECTIVE: The aim of this study was to test whether the AI model is more worthwhile than manual grading in community-based telemedicine screening for DR in the context of labor costs in urban China. METHODS: We conducted cost-effectiveness and cost-utility analyses by using decision-analytic Markov models with 30 one-year cycles from a societal perspective to compare the cost, effectiveness, and utility of 2 scenarios in telemedicine screening for DR: manual grading and an AI model. Sensitivity analyses were performed. Real-world data were obtained mainly from the Shanghai Digital Eye Disease Screening Program. The main outcomes were the incremental cost-effectiveness ratio (ICER) and the incremental cost-utility ratio (ICUR). The ICUR thresholds were set as 1 and 3 times the local gross domestic product per capita. RESULTS: The total expected costs for a 65-year-old resident were US $3182.50 and US $3265.40, while the total expected years without blindness were 9.80 years and 9.83 years, and the utilities were 6.748 quality-adjusted life years (QALYs) and 6.753 QALYs in the AI model and manual grading, respectively. The ICER for the AI-assisted model was US $2553.39 per year without blindness, and the ICUR was US $15,216.96 per QALY, which indicated that AI-assisted model was not cost-effective. The sensitivity analysis suggested that if there is an increase in compliance with referrals after the adoption of AI by 7.5%, an increase in on-site screening costs in manual grading by 50%, or a decrease in on-site screening costs in the AI model by 50%, then the AI model could be the dominant strategy. CONCLUSIONS: Our study may provide a reference for policy making in planning community-based telemedicine screening for DR in LMICs. Our findings indicate that unless the referral compliance of patients with suspected DR increases, the adoption of the AI model may not improve the value of telemedicine screening compared to that of manual grading in LMICs. The main reason is that in the context of the low labor costs in LMICs, the direct health care costs saved by replacing manual grading with AI are less, and the screening effectiveness (QALYs and years without blindness) decreases. Our study suggests that the magnitude of the value generated by this technology replacement depends primarily on 2 aspects. The first is the extent of direct health care costs reduced by AI, and the second is the change in health care service utilization caused by AI. Therefore, our research can also provide analytical ideas for other health care sectors in their decision to use AI.

Burden of near vision loss in China: findings from the Global Burden of Disease Study 2019.

PURPOSE: To investigate the burden of near vision loss (NVL) in China by year, age and gender from 1990 to 2019. METHODS: We used estimates from the Global Burden of Disease (GBD) 2019 study to report the prevalence and disability-adjusted life-years (DALYs) due to NVL in China. Estimates of crude counts and age-standardised rates per 100 000 population are accompanied by 95% uncertainty intervals (UIs). We summarised the age-specific and sex-specific patterns and trends regarding the burden of NVL in China, compared with seven neighbouring countries. RESULTS: From 1990 to 2019, the all-age number and rate for NVL prevalence and DALYs increased significantly in China (all p<0.001). The age-standardised rate decreased from 7538.1 (95% UI 6946.3 to 8075.1) to 7392.9 (95% UI 6855.8 to 7890.5) per 100 000 population for NVL prevalence (p=0.107), and from 74.9 (95% UI 69.6 to 79.9) to 73.8 (95% UI 70.6 to 80.1) per 100 000 population for DALYs (p=0.388). Women had higher NVL prevalence (t=170.1, p<0.001) and DALYs (t=192.5, p<0.001) than men. Higher disease burden of NVL was observed in the middle-aged and elderly population. The age-standardised prevalence and DALY rate attributable to NVL in China were lower than in India, North Korea, Pakistan (all p<0.001), but higher than Russia, South Korea, Singapore and Japan (all p<0.001). CONCLUSIONS: Despite a small decrease in age-standardised prevalence and DALYs due to NVL in China in the past two decades, the existing burden is still considerable and significantly higher compared with neighbouring developed countries. An approach that includes all stakeholders is needed to further reduce this burden.

Time trends and heterogeneity in the disease burden of trachoma, 1990-2019: a global analysis.

PURPOSE: To evaluate the epidemiological trends and associated risk factors of disease burden due to trachoma. METHODS: Data for the country-specific disability-adjusted life year (DALY) number, rate and age-standardised rate of trachoma together with related data of other common eye diseases were acquired from the Global Burden of Disease Study 2019 database. The Socio-Demographic Index (SDI), Human Development Index (HDI), inequality-adjusted HDI and other related indices were obtained from published data or publicly available databases. Regression analyses were conducted to evaluate the associations between potential risk factors and the age-standardised DALY burden of trachoma. RESULTS: The global DALY burden due to trachoma decreased by 37% from 1990 to 2019 and decreased by 69.8% after adjusting for age and population growth, and, in available 1990-2019 data, had the greatest reduction in attributable DALYs of all common eye disease, with the others analysed being cataract, glaucoma, refractive disorders and age-related macular degeneration. Women had higher age-standardised DALY burden due to trachoma than men (p<0.001). The African region (p<0.001) had the heaviest burden among global regions. The age-standardised DALY rate was higher in countries with lower income (p<0.001) and lower SDI (p<0.001). Higher disease burden due to trachoma was associated with lower HDI (ß=-48.102, 95% CI -86.888 to -9.316, p=0.016), lower SDI (ß=-48.063, 95% CI -83.702 to -12.423, p<0.001) and lower expected years of schooling (ß=-2.352, 95% CI -3.756 to -0.948, p=0.002). CONCLUSIONS: The global disease burden due to trachoma decreased from 1990 to 2019 and it had the greatest reduction compared with other common eye diseases. Lower HDI, socioeconomic status and educational level were related to a higher national disease burden of trachoma. Our findings could provide necessary information for trachoma control and prevention.

Effectiveness of community outreach screening for glaucoma in improving equity and access to eye care in Nigeria.

PURPOSE: To determine the effectiveness of community outreach screening for glaucoma in improving equity and access to eye care in Nigeria. METHODOLOGY: This was a prospective study in which two cohort of participants were recruited in Nigeria: 1 from 24 outreach screenings and another from consecutive patients presenting spontaneously to a tertiary eye clinic in Nigeria. Sociodemographic and clinical data were obtained from participants and compared. RESULTS: Our sample consisted of 120 patients with glaucoma or suspected glaucoma (6.38% of 1881 screenees) recruited from the 24 outreach screenings, and another 123 patients with glaucoma who presented spontaneously at the eye clinic. Participants from the screenings were significantly older (p=0.012), less educated (p<0.001), had lower incomes (p<0.001), lower glaucoma knowledge scores and were less aware of their glaucoma (both p<0.001) and were more likely to be dependent on relations and children (p=0.002) compared with clinic participants. Of the 120 patients identified at the screenings and referred to the clinic for definitive care, 39 (32.5%) presented at the clinic within 3 months. Reasons for poor uptake of referral services were lack of a felt need and lack of money for transportation. Considering only patients who accepted referral, they were still less educated (p<0.001), poorer (p=0.001) and less knowledgeable about glaucoma (p=0.003) than spontaneous clinic presenters. CONCLUSION: Outreach screening improved equity of access but its effects were somewhat reduced by poor uptake of referral care. Interventions such as free transportation and educational efforts may improve the uptake of referral services and maximise equity gains.

Modelling ready-made spectacle coverage for children and adults using a large global database.

BACKGROUND/AIMS: To model the suitability of conventional ready-made spectacles (RMS) and interchangeable-lens ready-made spectacles (IRMS) with reference to prescribing guidelines among children and adults using a large, global database and to introduce a web-based application for exploring the database with user-defined eligibility criteria. METHODS: Using refractive power and interpupillary distance data for near and distance spectacles prescribed to children and adults during OneSight clinics in 27 countries, from 2 January 2016 to 19 November 2019, we modelled the expected suitability of RMS and IRMS spectacle designs, compared with custom-made spectacles, according to published prescribing guidelines. RESULTS: Records of 18 782 presbyopic adult prescriptions, 70 619 distance adult prescriptions and 40 862 paediatric prescriptions were included. Globally, 58.7%-63.9% of adults could be corrected at distance with RMS, depending on the prescribing cut-off. For presbyopic adult prescriptions, coverage was 44.1%-60.9%. Among children, 51.8% were eligible for conventional RMS. Coverage for all groups was similar to the above for IRMS. The most common reason for ineligibility for RMS in all service groups was astigmatism, responsible for 27.2% of all ineligible adult distance prescriptions using the strictest cut-off, 31.4% of children's prescriptions and 28.0% of all adults near prescriptions globally. CONCLUSION: Despite their advantages in cost and convenience, coverage delivered by RMS is limited under current prescribing guidelines, particularly for children and presbyopic adults. Interchangeable designs do little to remediate this, despite extending coverage for anisometropia. Our free application allows users to estimate RMS coverage in specific target populations.

Impact of Artificial Intelligence Assessment of Diabetic Retinopathy on Referral Service Uptake in a Low-Resource Setting: The RAIDERS Randomized Trial.

Purpose: This trial was designed to determine if artificial intelligence (AI)-supported diabetic retinopathy (DR) screening improved referral uptake in Rwanda. Design: The Rwanda Artificial Intelligence for Diabetic Retinopathy Screening (RAIDERS) study was an investigator-masked, parallel-group randomized controlled trial. Participants: Patients ≥ 18 years of age with known diabetes who required referral for DR based on AI interpretation. Methods: The RAIDERS study screened for DR using retinal imaging with AI interpretation implemented at 4 facilities from March 2021 through July 2021. Eligible participants were assigned randomly (1:1) to immediate feedback of AI grading (intervention) or communication of referral advice after human grading was completed 3 to 5 days after the initial screening (control). Main Outcome Measures: Difference between study groups in the rate of presentation for referral services within 30 days of being informed of the need for a referral visit. Results: Of the 823 clinic patients who met inclusion criteria, 275 participants (33.4%) showed positive findings for referable DR based on AI screening and were randomized for inclusion in the trial. Study participants (mean age, 50.7 years; 58.2% women) were randomized to the intervention (n = 136 [49.5%]) or control (n = 139 [50.5%]) groups. No significant intergroup differences were found at baseline, and main outcome data were available for analyses for 100% of participants. Referral adherence was statistically significantly higher in the intervention group (70/136 [51.5%]) versus the control group (55/139 [39.6%]; P = 0.048), a 30.1% increase. Older age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.02-1.05; P < 0.0001), male sex (OR, 2.07; 95% CI, 1.22-3.51; P = 0.007), rural residence (OR, 1.79; 95% CI, 1.07-3.01; P = 0.027), and intervention group (OR, 1.74; 95% CI, 1.05-2.88; P = 0.031) were statistically significantly associated with acceptance of referral in multivariate analyses. Conclusions: Immediate feedback on referral status based on AI-supported screening was associated with statistically significantly higher referral adherence compared with delayed communications of results from human graders. These results provide evidence for an important benefit of AI screening in promoting adherence to prescribed treatment for diabetic eye care in sub-Saharan 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.

A pilot cost-benefit analysis of a children's spectacle reimbursement scheme: Evidence for Including children's spectacles in Mongolia's Social Health Insurance.

BACKGROUND AND AIM: Globally, 12.8 million children have vision impairment due to uncorrected refractive error (URE). In Mongolia, one in five children needs but do not have access to spectacles. This pilot cost-benefit analysis aims to estimate the net benefits of a children's spectacles reimbursement scheme in Mongolia. METHODS: A willingness-to-pay (WTP) survey using the contingent valuation method was administered to rural and urban Mongolia respondents. The survey assessed WTP in additional annual taxes for any child with refractive error to be provided government-subsidised spectacles. Net benefits were then calculated based on mean WTP (i.e. benefit) and cost of spectacles. RESULTS: The survey recruited 50 respondents (mean age 40.2 ± 9.86 years; 78.0% women; 100% response rate) from rural and urban Mongolia. Mean WTP was US$24.00 ± 5.15 (95% CI US$22.55 to 25.35). The average cost of a pair of spectacles in Mongolia is US$15.00. Subtracting the average cost of spectacles from mean WTP yielded a mean positive net benefit of US$9.00. CONCLUSION: A spectacle reimbursement scheme is potentially a cost-effective intervention to address childhood vision impairment due to URE in Mongolia. These preliminary findings support the proposal of the inclusion of children's spectacles into existing Social Health Insurance. A much larger random sample could be employed in future research to increase the precision and generalisability of findings.

Outreach screening to address demographic and economic barriers to diabetic retinopathy care in rural China.

IMPORTANCE: Poor access to existing care for diabetic retinopathy (DR) limits effectiveness of proven treatments. OBJECTIVES: We examined whether outreach screening in rural China improves equity of access. DESIGN, SETTING AND PARTICIPANTS: We compared prevalence of female sex, age > = 65 years, primary education or below, and requiring referral care for DR between three cohorts with diabetes examined for DR in neighboring areas of Guangdong, China: passive case detection at secondary-level hospitals (n = 193); persons screened during primary-level DR outreach (n = 182); and individuals with newly- or previously-diagnosed diabetes in a population survey (n = 579). The latter reflected the "ideal" reach of a screening program. RESULTS: Compared to the population cohort, passive case detection reached fewer women (50·8% vs. 62·3%, p = 0·006), older adults (37·8% vs. 51·3%, p < 0·001), and less-educated persons (39·9% vs. 89·6%, p < 0·001). Outreach screening, compared to passive case detection, improved representation of the elderly (49·5% vs. 37·8%, p = 0·03) and less-educated (70·3% vs. 39·9%, p<0·001). The proportion of women (59.8% vs 62.3%, P>0.300) and persons aged > = 65 years (49.5% vs 51.3%, p = 0.723) in the outreach screening and population cohorts did not differ significantly. Prevalence of requiring referral care for DR was significantly higher in the outreach screening cohort (28·0%) than the population (14·0%) and passive case detection cohorts (7·3%, p<0·001 for both). CONCLUSIONS AND RELEVANCE: Primary-level outreach screening improves access for the poorly-educated and elderly, and removes gender inequity in access to DR care in this setting, while also identifying more severely-affected patients than case finding in hospital.

Advancing the Sustainable Development Goals through improving eye health: a scoping review.

UN member states have committed to achieving the Sustainable Development Goals (SDGs) by 2030. This Review examines the published evidence on how improving eye health can contribute to advancing the SDGs (beyond SDG 3). We identified 29 studies that showed direct benefits from providing eye health services on SDGs related to one or more of poverty (SDGs 1, 2, and 8), education (SDG 4), equality (SDGs 5 and 10), and sustainable cities (SDG 11). The eye health services included cataract surgery, free cataract screening, provision of spectacles, trichiasis surgery, rehabilitation services, and rural community eye health volunteers. These findings provide a comprehensive perspective on the direct links between eye health services and advancing the SDGs. In addition, eye health services likely have indirect effects on multiple SDGs, mediated through one of the direct effects. Finally, there are additional plausible links to other SDGs, for which evidence has not yet been established.

Time trends, associations and prevalence of blindness and vision loss due to glaucoma: an analysis of observational data from the Global Burden of Disease Study 2017.

OBJECTIVE: To estimate global prevalence of blindness and vision loss caused by glaucoma, and to evaluate the impact of socioeconomic factors on it. DESIGN: A population-based observational study. SETTING: The prevalence of blindness and vision loss due to glaucoma were obtained from the Global Burden of Disease Study 2017 database. The Human Development Index (HDI), inequality-adjusted HDI and other socioeconomic data were acquired from international open databases. MAIN OUTCOME MEASURES: The prevalence of blindness and vision loss due to glaucoma by age, gender, subregion and Socio-Demographic Index (SDI) levels. Multiple linear regression analysis was performed to explore the associations between the prevalence and socioeconomic indicators. RESULTS: The overall age-standardised prevalence of blindness and vision loss due to glaucoma worldwide was 81.5 per 100 000 in 1990 and 75.6 per 100 000 in 2017. In 2017, men had a higher age-standardised prevalence than women (6.07% vs 5.42%), and the worldwide prevalence increased with age, from 0.5 per 100 000 in the 45-49 year age group to 112.9 per 100 000 among those 70+. Eastern Mediterranean and African regions had the highest prevalence during the whole period, while the Americas region had the lowest prevalence. The prevalence was highest in low-SDI and low-income regions while lowest in high-SDI and high-income regions over the past 27 years. Multiple linear regression showed cataract surgery rate (ß=-0.01, p=0.009), refractive error prevalence (ß=-0.03, p=0.024) and expected years of schooling (ß= -8.33, p=0.035) were associated with lower prevalence, while gross national income per capita (ß=0.002, p<0.001) was associated with higher prevalence. CONCLUSIONS: Lower socioeconomic levels and worse access to eyecare services are associated with higher prevalence of glaucoma-related blindness and vision loss. These findings provide evidence for policy-makers that investments in these areas may reduce the burden of the leading cause of irreversible blindness.

Time trends, associations and global burden of intraocular foreign bodies.

PURPOSE: To estimate the disease burden due to intraocular foreign bodies (IOFBs) and evaluate contributions of various risk factors to IOFB-associated disability-adjusted life-years (DALYs). METHODS: Global, regional and country-level number, rate and age-standardised rate of DALYs due to IOFBs were acquired from the Global Burden of Disease Study 2017 database. The Human Development Index (HDI) and other region and country-level data were obtained from open databases. Time trends for number, rate and age-standardised rate of DALYs due to IOFBs were calculated. Regression analysis was used to evaluate associations between age-standardised rate of DALYs and potential predictors. RESULTS: Global DALYs due to IOFBs rose by 43.7% between 1990 (139 (95% CI 70.8 to 233) thousand) and 2017 (202 (95% CI 105 to 335) thousand). The DALY rate remained stable while the age-standardised rate decreased during this period. Higher disease burden due to IOFBs was associated with higher glaucoma prevalence (ß=0.006, 95% CI 0.003 to 0.09, p<0.001), lower refractive error prevalence (ß=-0.0005, 95% CI -0.0007 to -0.0002, p<0.001), and lower income (ß=-0.020, 95% CI -0.035 to -0.006, p=0.007). CONCLUSION: Predictors of a greater burden of IOFB disability generally point to lower socioeconomic level. The association with glaucoma may reflect a complication of IOFB, increasing risk of vision loss and disability.

A Review to Populate A Proposed Cost-Effectiveness Analysis of Glaucoma Screening in Sub-Saharan Africa.

To populate a proposed cost-effectiveness analysis of glaucoma screening in Sub-Saharan Africa (SSA).A complete search was conducted on PubMed, Medline and African Journals Online (AJOL) to obtain relevant published articles, which were included in this review. All relevant articles on prevalence of glaucoma in SSA and among other African-derived populations, severity of glaucoma, cost of diagnosis and management, clinical effectiveness of glaucoma screening and treatment and the different glaucoma screening strategies in SSA were reviewed.Population screening interventions for glaucoma may be considered as follows: standalone screening for glaucoma, screening for glaucoma during cataract outreach, and screening incorporated with diabetic retinopathy image review using tele-ophthalmology. Our review suggests that cost of glaucoma treatment is relatively low with cost of medical treatment ranging from USD 273 to USD 480 per year/patient and surgical treatment cost of USD 283 per patient as with other developing countries. Compliance with medication is moderate to good in about 50% of glaucoma patients. Prevalence of glaucoma is much higher in SSA and almost 50% of glaucoma patients are blind in at least one eye at presentation in clinics (without outreach screening). Our review suggests a moderate sensitivity and specificity in identifying glaucoma with basic equipment (direct ophthalmoscope, contact tonometer and frequency doubling technology) during outreach screening although about a third or fewer take up glaucoma services in clinics.Our review provides the necessary information to conduct a cost-effective analysis of glaucoma screening in SSA using the decision Markov model.