Equity and Blindness: Closing Evidence Gaps to Support Universal Eye Health

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.

Prevalence and secular trends of four causes of blindness and visual impairment in Iran (1990-2019): a comparative study based on the Global Burden of Disease project's data

PURPOSE

The purpose of this study was to investigate the prevalence of cataracts, refractive disorders, age-related macular disease (AMD), and glaucoma, as well as their trends from 1990 to 2019 in Iran, in comparison with high-middle socio-demographic index (HMSDI) countries and the world, using the Global Burden of Disease (GBD) 2019 study.

METHODS

The GBD study provided data on the prevalence of blindness and visual impairment (VI), as well as four of their causes including cataracts, refractive disorders, age-related macular disease (AMD), and glaucoma. Using Joinpoint analysis, the annual percent change (APC) was calculated to assess the trend of change in prevalence in each category of diseases from 1990 to 2019, stratified by sex and age, for Iran, HMSDI countries, and the world.

RESULTS

In 2019, refractive errors and cataracts were the most common causes of blindness and VI for both genders in Iran, HMSDI countries and the world. Iran had a higher age-standardized prevalence in all four categories of ophthalmologic disorders compared to HMSDI countries and the world for both genders in 2019. Additionally, the age-specific prevalence of all four disorders in 2019 was higher in Iran compared to HMSDI countries. However, in terms of trends of prevalence from 1990 to 2019, the rate of reduction for the four ophthalmologic disorders in Iran was higher than in HMSDI and the world for both males and females. Furthermore, Iran had a greater percentage of reduction in prevalence for all age groups in all four disorders compared to HMSDI countries.

CONCLUSION

The prevalence of cataracts, refractive errors, AMD, and glaucoma in Iran was higher compared to HMSDI countries in 2019 for both sexes and all age groups, but the trends of prevalence for all four disorders from 1990 to 2019 in Iran had a higher slope of reduction compared to HMSDI countries for all ages and sexes.

Prevalence of cataract and its contributing factors in Iranian elderly population: the Gilan eye study

PURPOSE

To report the prevalence and the associated factors leading to cataract among the Iranian population living in Gilan Province, Iran.

METHODS

This population-based cross-sectional study was performed from June to November 2014 on 2,975 residents aged ≥ 50 years old living in urban and rural regions of the Gilan Province in Iran. A representative sample of residents in the province was recruited into the study through door-to-door visiting, and baseline data were collected by questionnaire. All participants were referred to the medical center for comprehensive ophthalmic examination, laboratory tests, and blood pressure measurement.

RESULTS

Among the population, 2,588 (86.99%) subjects were eligible to be included in this study, categorized either into the cataract or the non-cataract group. The mean age of participants was 62.59 ± 8.92 years, and 57.5% were female. Higher prevalence of cataract was found in individuals of older ages (odds ratio (OR) = 1.13; 95% confidence interval (CI) = 1.10 to 1.16; P < 0.001) and a history of previous ocular surgery (OR = 5.78; 95% CI = 2.28 to 14.63; P < 0.001). At the same time, a lower prevalence of cataract was seen in patients exposed to sunlight for more than 4 h per day (OR = 0.49; 95% CI = 0.32 to 0.73; P = 0.001).

CONCLUSION

Cataract affects 50.50% of the study population, especially those over 80. The mildest form of cataract, grade zero, is the most common. Surgery for cataract has good outcomes. The risk of cataract is higher for those older or who have had eye surgeries. People not affected by cataract tend to be exposed to more sunlight.

Significant improvements in cataract treatment and persistent inequalities in access to cataract surgery among older Poles from 2009 to 2019: results of the PolSenior and PolSenior2 surveys

Background and aims

Cataract is the leading cause of visual impairment and blindness among older adults worldwide, that can be corrected through surgical interventions. However, diagnosis and treatment bias can be observed, and it is a major issue for improving health policies. Therefore, we assessed a declared prevalence of cataract and the frequency of surgical treatment of this condition in the Polish population in the years 2009-2019. To provide evidence of health inequalities, we compared operated and non-operated seniors using selected socioeconomic factors and identified variables affecting the availability of cataract surgery services over a 10-year follow-up period.

Methods

An analysis based on a survey among 4,905 participants of the nationwide PolSenior study conducted in 2008-2009, and 5,031 participants of PolSenior2 conducted one decade later to assess the health of Poles over 65 years of age.

Results

Cataract diagnosis was declared by 25.5 and 28.2% of the study population in PolSenior and PolSenior2 surveys, respectively. Out of those diagnosed with cataract in PolSenior, 46.5% underwent surgical treatment for at least one eye. This rate increased up to 67.9% in the survey conducted 10 years later. Independent factors increasing the chance for cataract surgery in both cohorts included male sex and age > 75 years. Additional factors were self-reported good health status in PolSenior and lack of financial problems in purchasing medicines in PolSenior2. Over the investigated decade, the chances for cataract surgical treatment increased in single-living and widowed patients. The shortage of funds for medications remained the only significant barrier for surgery.

Conclusion

Although the prevalence of cataract in the older adult population in Poland has not changed from 2009 to 2019, the rate of cataract surgeries has considerably increased over the analyzed decade. Patients with lower socioeconomic status and women have lower access to surgical cataract management.

National sex- and age-specific burden of blindness and vision impairment by cause in Mexico in 2019: a secondary analysis of the Global Burden of Disease Study 2019

Background

Reliable national estimations for blindness and vision impairment are fundamental to assessing their burden and developing public health policies. However, no comprehensive analysis is available for Mexico. Therefore, in this observational study we describe the national burden of blindness and vision loss by cause and severity during 2019.

Methods

Using public data from the Global Burden of Disease (GBD) study 2019, we present national prevalence and years lived with disability (YLDs) counts and crude and age-standardized rates (per 100,000 people) of total, severity- and cause-specific blindness and vision impairment with 95% uncertainty intervals (UIs) by sex and age group.

Findings

In Mexico, the burden of blindness and vision impairment was estimated at 11.01 million (95% UI, 9.25-13.11) prevalent cases and 384.96 thousand (259.57-544.24) YLDs during 2019. Uncorrected presbyopia caused the highest burden (6.06 million cases, 4.36-8.08), whereas severe vision loss and blindness affected 619.40 thousand (539.40-717.73) and 513.84 thousand (450.59-570.98) people, respectively. Near vision loss and refraction disorders caused 78.7% of the cases, whereas neonatal disorders and age-related macular degeneration were among the least frequent. Refraction disorders were the main cause of moderate and severe vision loss (61.44 and 35.43%), and cataracts were the second most frequent cause of blindness (26.73%). Females suffered an overall higher burden of blindness and vision impairment (54.99% and 52.85% of the total cases and YLDs), and people >50 years of age suffered the highest burden, with people between 70 and 74 years being the most affected.

Interpretation

Vision loss represents a public health problem in Mexico, with women and older people being the most affected. Although the causes of vision loss contribute differentially to the severity of visual impairment, most of the impairment is avoidable. Consequently, a concerted effort at different levels is needed to alleviate this burden.

Funding

This study received no funding.

Cataract services for all: Strategies for equitable access from a global modified Delphi process

Vision loss from cataract is unequally distributed, and there is very little evidence on how to overcome this inequity. This project aimed to engage multiple stakeholder groups to identify and prioritise (1) delivery strategies that improve access to cataract services for under-served groups and (2) population groups to target with these strategies across world regions. We recruited panellists knowledgeable about cataract services from eight world regions to complete a two-round online modified Delphi process. In Round 1, panellists answered open-ended questions about strategies to improve access to screening and surgery for cataract, and which population groups to target with these strategies. In Round 2, panellists ranked the strategies and groups to arrive at the final lists regionally and globally. 183 people completed both rounds (46% women). In total, 22 distinct population groups were identified. At the global level the priority groups for improving access to cataract services were people in rural/remote areas, with low socioeconomic status and low social support. South Asia and Sub-Saharan Africa were the only regions in which panellists ranked women in the top 5 priority groups. Panellists identified 16 and 19 discreet strategies to improve access to screening and surgical services, respectively. These mostly addressed health system/supply side factors, including policy, human resources, financing and service delivery. We believe these results can serve eye health decision-makers, researchers and funders as a starting point for coordinated action to improve access to cataract services, particularly among population groups who have historically been left behind.

Global, regional, and national years lived with disability due to blindness and vision loss from 1990 to 2019: Findings from the Global Burden of Disease Study 2019

Purpose

This study aimed to provide a comprehensive assessment of burden estimates and the secular trend of blindness and vision loss, as measured by years lived with disability (YLDs), at the global, regional, and national levels.

Methods

The age-standardized YLD rates (ASYRs) due to blindness and vision loss and its subtypes, including moderate vision loss, severe vision loss, blindness, and presbyopia, from 1990 to 2019 were extracted from the Global Burden of Disease Study 2019 database. The estimated annual percentage changes (EAPCs) were calculated to quantify the temporal trends in the ASYRs due to blindness and vision loss.

Results

In 2019, the global ASYRs per 100,000 population was 327.98 for blindness and vision loss, specifically, 85.81 for moderate vision loss, 74.86 for severe vision loss, 95.03 for blindness, and 62.27 for presbyopia. From 1990 to 2019, the ASYRs due to blindness and vision loss slightly decreased. Females showed higher ASYRs than males in 2019. The global highest ASYRs were observed in South Asia and sub-Saharan Africa. Negative associations were found between the burden estimates of blindness and vision loss and the sociodemographic index levels. The EAPCs of ASYRs in blindness and vision loss were significantly negatively correlated with the ASYRs in 1990 and positively correlated with human development indices in 2019.

Conclusions

Globally, blindness and vision loss continue to cause great losses of healthy life. Reasonable resource allocation and health-service planning are needed for the prevention and early intervention of disabilities caused by vision loss.

Improving equity, efficiency and adherence to referral in Pakistan's eye health programmes: Pre- and post-pandemic onset

Background

Over one billion people worldwide live with avoidable blindness or vision impairment. Eye Health Programmes tackle this by providing screening, primary eye care, refractive correction, and referral to hospital eye services. One point where patients can be lost in the treatment journey is adherence to hospital referral.

Context

Peek Vision's software solutions have been used in Pakistan with the goal of increasing eye health programme coverage and effectiveness. This involved collaboration between health system stakeholders, international partners, local community leaders, social organizers and “Lady Health Workers”.

Results

From the beginning of the programmes in November 2018, to the end of December 2021, 393,759 people have been screened, 26% of whom (n = 101,236) needed refractive services or secondary eye care, and so were referred onwards to the triage centers or hospital services. Except for a short period affected heavily by COVID-19 pandemic, the programmes reached an increasing number of people over time: screening coverage improved from 774 people per month to over 28,300 people per month. Gathering and discussing data regularly with stakeholders and implementers has enabled continuous improvement to service delivery. The quality of screening and adherence to hospital visits, gender balance differences and waiting time to hospital visits were also improved. Overall attendance to hospital appointments improved in 2020 compared to 2019 from 45% (95% CI: 42–48%) to 78% (95% CI: 76–80%) in women, and from 48% (95% CI: 45–52%) to 70% (95% CI: 68–73%) in men. These patients also accessed treatment more quickly: 30-day hospital referral adherence improved from 12% in 2019 to 66% in 2020. This approach helped to utilize refractive services more efficiently, reducing false positive referrals to triage from 10.6 to 5.9%. Hospital-based services were also utilized more efficiently, as primary eye care services and refractive services were mainly delivered at the primary healthcare level.

Discussion

Despite various challenges, we demonstrate how data-driven decisions can lead to health programme systems changes, including patient counseling and appointment reminders, which can effectively improve adherence to referral, allowing programmes to better meet their community's needs.

Piloting targeted glaucoma screening: experiences of eye care services in Ganjam district, Odisha state, India

Background

The number of patients with visual impairment and blindness from glaucoma is rapidly increasing with wide-ranging impacts for individuals and societies. However, the disease often goes undiagnosed for a long time, especially in low- and middle-income countries where healthcare services are limited. This paper presents the results of a pilot programme, which integrated targeted glaucoma screenings of people aged ≥40 y in community-based eye care services in the Ganjam district of Odisha state, India.

Methods

Using routine programme data, descriptive statistics were produced for the characteristics of patients participating in the screening programme and the rate and uptake of glaucoma referrals. Bivariate analysis was used to examine associations between patient characteristics, clinical risk factors and glaucoma diagnosis.

Results

Out of 23 356 individuals aged ≥40 y screened for glaucoma over a period of 18 mo, 2219 (9.5%) were referred and 2031 presented for further examination. Among them, almost half (n=968, 48%) were diagnosed with glaucoma, representing a screening to diagnosis conversion rate of 4.14% (95% CI 3.9 to 4.4%). A positive diagnosis of glaucoma among suspects was associated with female sex, age >60 y, visual impairment, vertical cap-to-disc ratio ≥0.6:1, intraocular pressure ≥30 mmHg and shallow anterior chamber (p<0.001).

Conclusions

The importance of targeted screening for glaucoma using simple referral criteria to identify patients at high risk of vision loss who can benefit from treatment is critical to slow the progression of the disease and the prevention of blindness. Further studies assessing costs of the targeted screening, the role of technology in improving programme effectiveness and efficiency and the longer term compliance with treatment are needed to support glaucoma policy frameworks, guidelines and clinical practice.

Evidence on cataract in low- and middle-income countries: an updated review of reviews using the evidence gap maps approach

In 2014, Sightsavers developed the first evidence gap map (EGM) to assess the extent and quality of review-level evidence on cataract relevant to low-and middle-income countries. The EGM identified 52 studies across five broad themes. This paper reports the update of the EGM conducted in 2021 and changes to the extent and quality of the evidence base. We updated the EGM using the exact process conducted to develop the original. Searches were run to 14 September 2021, and two independent reviewers selected eligible studies, critically appraised them and extracted data using the Supporting the Use of Research Evidence checklist. A summary quality assessment was shared with the authors for comments. Forty-six new reviews were identified, and the EGM now includes 98 reviews. The new reviews predominantly focus on treatment and risk factors. The overall methodological quality was found to be improved, with 13/46 reporting high confidence in findings. EGMs remain a useful tool for policy-makers to make informed decisions and periodic updates are important to assess changes and to refine the focus for future research. The EGM highlights significant disparity in the topics addressed by reviews, with health system interventions particularly neglected.

Prevalence of blindness and distance vision impairment in the Gambia across three decades of eye health programming

BACKGROUND/AIMS

The 1986 Gambia National Eye Health Survey provided baseline data for a National Eye Health Programme. A second survey in 1996 evaluated changes in population eye health a decade later. We completed a third survey in 2019, to determine the current state of population eye health, considering service developments and demographic change.

METHODS

We estimated prevalence and causes of vision impairment (VI) in a nationally representative population-based sample of adults 35 years and older. We used multistage cluster random sampling to sample 10 800 adults 35 and above in 360 clusters of 30. We measured monocular distance visual acuity (uncorrected and with available correction) using Peek Acuity. Participants with either eye uncorrected or presenting (with available correction) acuity <6/12 were retested with pinhole and refraction, and dilated exams were completed on all eyes by ophthalmologists using a direct ophthalmoscope, slit lamp and 90 D lens.

RESULTS

We examined 9188 participants (response rate 83%). The 2013 census age-sex adjusted prevalence of blindness (presenting acuity<3/60 in better seeing eye) was 1.2% (95% CI 0.9 to 1.4) and of moderate or severe VI (MSVI,<6/18 to ≥3/60) was 8.9% (95% CI 9.1 to 9.7). Prevalence of all distance VI (<6/12) was 13.4% (12.4-14.4). Compared with 1996, the relative risk of blindness decreased (risk ratio 0.7, 95% CI 0.5 to 1.0) and MSVI increased (risk ratio 1.5, 95% CI 1.2 to 0.17).

CONCLUSION

Significant progress has been made to reduce blindness and increase access to eye health across the Gambia, with further work is needed to decrease the risk of MSVI.

Knowledge, Attitudes and Practices of Eye Health among Public Sector Eye Health Workers in South Africa

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 <5 years showed a good attitude (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 <5 years of employment (aOR = 26.600; 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.

Changes in Eye Health and Service Coverage in Nampula, Mozambique between 2011 and 2018

Purpose: Globally, there are few examples of repeated eye health surveys to assess changes in prevalence and causes of visual impairment, and service coverage over time. Two separate, unlinked rapid assessments of avoidable blindness (RAAB) were conducted in Nampula province, Mozambique in 2011 and 2018. This paper reports the observed changes and examines how the trends differ for males and females.Methods: Standard RAAB methodology was used in both studies. Two-stage cluster sampling was used to generate random samples of adults aged over 50 years. Participants underwent a simplified visual acuity (VA) exam, a lens exam and posterior segment exam using a direct ophthalmoscope for all subjects with presenting VA<6/18. Data were analysed using Stata and logistic regression models were developed to assess changes.Results: The 2011 study enrolled 3,050 people and examined 96.9% (2,954 people). The 2018 survey enrolled 4,191 people and examined 95.8% (4,015 people). Age- and sex-adjusted estimates of blindness decreased from 6.2% in 2011 to 4.5% in 2018 (z = -2.21, p = .028). Cataract surgical coverage was higher among males in both surveys (13.4% among males vs 7.7% among females in 2011, and 40.0% among males vs 19.4% among females in 2018) and the gender disparity grew between surveys.Conclusion: Significant changes were observed in the eye health and service coverage between 2011 and 2018. Further improvements to services are required to improve access for women and people with moderate visual impairment.

Prevalence and associated factors of vision loss in the South African National Health and Nutrition Examination Survey (SANHANES-1)

BACKGROUND

Vision loss is a major public health concern that significantly affects developing countries, including South Africa. Although existing literature have reported on the prevalence, causes, and impact of vision loss on the quality of life of affected individuals (children and adults) in parts of South Africa, there is no evidence of the prevalence and associated factors of vision loss in the general population. Hence, this study aimed to determine the prevalence of vision loss and its associated factors in South Africa using a population-based survey.

METHODS

Secondary analyses were conducted using data from the South African National Health and Nutrition Examination Survey (SANHANES-1), a population-based national health survey conducted from 2011 to 2012. Vision loss was defined as presenting visual acuity (PVA) worse than Snellen 6/12 in the better eye. Visual acuity was assessed by clinicians and participants' subjective response to vision-related questions. Univariate and multiple logistic regression models were used to examine the association of the independent variables with vision loss.

RESULTS

The analytic sample comprised 4346 individuals with a mean age of 39.1 years. Female sex accounted for 55.6% of the participants. The prevalence of vision loss among participants was 9.2% (95% CI: 7.7-10.9). Older age (45-54 years, OR = 2.99, p < 0.001; 55-64 years, OR = 5.78, p < 0.001 and ≥ 65 years, OR = 5.12, p < 0.001), female sex (OR = 1.50, p = 0.016), and previous diabetes diagnosis (OR = 2.28, p = 0.001) were significantly associated with increased odds of vision loss. Further, secondary school education (OR = 0.71, p = 0.031), white ethnicity (OR = 0.11, p = 0.007), residing in Mpumalanga province (OR = 0.12, p < 0.001) and having never had an eye examination (OR = 0.56, p = 0.003) were significantly associated with reduced odds of vision loss.

CONCLUSION

Almost one in ten participants had vision loss. Adopting strategies targeted at reducing barriers to the utilization of eye care services will promote early detection and management of blinding conditions, and thereby, decrease the burden of vision loss in South Africa.

Feasibility of a cluster randomized controlled trial on the effectiveness of peer-led health education interventions to increase uptake of retinal examination for diabetic retinopathy in Kirinyaga, Kenya: a pilot trial

Background

People living with diabetes can reduce their risk of vision loss from diabetic retinopathy by attending screening, which enables early detection and timely treatment. The aim of this pilot trial was to assess the feasibility of a full-scale cluster randomized controlled trial of an intervention to increase uptake of retinal examination in this population, as delivered within existing community-based diabetes support groups (DSGs).

Methods

All 16 DSGs in Kirinyaga county were invited to participate in the study. The first two groups recruited took part in the pilot trial. DSG members who met the eligibility criteria were recruited before the groups that were randomized to the two arms. In the intervention group, two peer educators were trained to deliver monthly DSG-based eye health education and individual telephone reminders to attend screening. The control group continued with usual DSG practice which is monthly meetings without eye health education. The recruitment team and outcome assessors were masked to the allocation. We documented the study processes to ascertain the feasibility, acceptability, and potential effectiveness of the intervention. Feasibility was assessed in terms of clarity of study procedures, recruitment and retention rates, level of acceptability, and rates of uptake of eye examination. We set the target feasibility criteria for continuation to the main study to be recruitment of 50 participants in the trial, 80% monthly follow-up rates for individuals, and no attrition of clusters.

Results

Of the 122 DSG members who were assessed for eligibility, 104 were recruited and followed up: 51 (intervention) and 53 (control) arm. The study procedures were well understood and easy to apply. We learnt the DSG meeting days were the best opportunities for recruitment. The study had a high acceptance rate (100% for clusters, 95% for participants) and high follow-up and retention rate (100% of those recruited). All clusters and participants were analysed. We observed that the rate of incidence of eye exam was about 6 times higher in the intervention arm as compared to the control arm. No adverse unexpected events were reported in either arm.

Conclusions

The study is feasible and acceptable in the study population. The results support the development of a full-scale cluster RCT, as the success criteria for the pilot were met.

Trial registration

Pan African Clinical Trials Registry PACTR201707002430195 Registered on 25 July 2017.

Equity was rarely considered in Cochrane Eyes and Vision systematic reviews and primary studies on cataract

OBJECTIVE

We sought to understand the extent to which Cochrane Eyes and Vision systematic reviews of interventions for cataract, and primary studies, consider equity.

STUDY DESIGN AND SETTING

This is a review of Cochrane Eyes and Vision systematic reviews (CSRs) on cataract published on the Cochrane Library (end of March 2019) (n = 23), and recently published primary studies included in those reviews (n = 62), using the PROGRESSPlus framework.

RESULTS

One CSR considered equity as a topic. Four (17%) CSRs included a low- and middle-income country (LMIC) author; one of them was a first author. The CSR with equity as a main topic restricted primary studies to those conducted in LMICs; otherwise none of the systematic reviews used PROGRESS factors as inclusion or exclusion criteria. None of the CSRs reported subgroup analyses by any PROGRESS factor, although these were planned in two. Two of the primary studies were led by an LMIC author; 42% involved LMIC authors; 37% were conducted in LMICs; 73% of studies reported on gender/sex of participants, but other PROGRESS factors were less frequently reported. Three studies reported subgroup analyses by sex; one reported subgroup analyses by race/ethnicity.

CONCLUSION

PROGRESS factors and equity are rarely considered in studies of interventions for cataract, and this is reflected in the associated Cochrane reviews.

Strengths and weaknesses of eye care services in sub-Saharan Africa: a meta-synthesis of eye health system assessments

Background

In sub-Saharan Africa (SSA), the delivery of eye care services continues to be undermined by health systems performance bottlenecks. There is a growing focus by partners in the sector on the analysis of the different components of eye care within the wider health system context to diagnose and manage interactions in ways that achieve more effective improvements. However, there has been no attempt to date to systematically synthesize these studies. In this study, we conducted a meta-synthesis of eye health system assessments to gain a more comprehensive understanding of the current systems and how they can be strengthened across different SSA contexts.

Methods

We conducted a comprehensive search for eye health system assessment reports using global and regional websites of the WHO and other organizations supporting eye care in sub-Saharan Africa. A range of online databases with no language restrictions (PubMed, EMBASE, MEDLINE, PsycINFO and CINAHL) were searched for peer-reviewed publications referring to eye health system assessment (EHSA) or eye care service assessment tool (ECSAT). Assessments were included if they used the ECSAT or EHSA tool; were conducted in sub-Saharan Africa; and had been completed with full reports available in the public domain by January 15, 2019. A combination of framework and thematic syntheses was used.

Results

Our search strategies yielded a total of 12 assessments conducted in nine countries using the ECSAT/EHSA tool in Sub-Saharan Africa. Eight assessments met our inclusion criteria: four were from West Africa, two from East Africa and two from Southern Africa. Across the eight countries, findings show considerable progress and improvements in the areas of governance, organisation, financing, provision, and coverage of eye care. However, several systemwide weaknesses were found to continue to impede quality eye health service planning and delivery across the countries included in this review.

Conclusions

These findings highlight the need for national governments and iNGOs to invest in conducting and wider use of these assessments. Such analyses are particularly useful in building links between different system elements and in finding innovative, more flexible solutions and partnerships – needed to address avoidable vision loss in resource poor settings.

Who benefits most from extending financial protection for cataract surgery in Vietnam? An extended cost-effectiveness analysis of small incision surgery

Treatment costs remain a barrier for having timely cataract surgery in Vietnam, particularly for females and the poor, despite significant progress in achieving universal health coverage (UHC). This study evaluated the potential impact, on health and financial protection, of eliminating medical and non-medical out-of-pocket costs associated with cataract surgery. An extended cost-effectiveness analysis (ECEA) was conducted with a societal perspective. The ECEA modelled how many more disability-adjusted life years (DALYs) and cases of catastrophic health expenditure (CHE) and medical impoverishment could be averted across income quintiles and between males and females. Two programmes were evaluated: (1) eliminating medical out-of-pocket costs for small incision cataract surgery and (2) Programme A plus a voucher programme covering non-medical out-of-pocket costs. Compared with current, the incremental cost per year of Programme A was estimated to be $833 396 and $1 641 835 for Programme B, each representing <0.01% of total health care spending in 2016. Males and females in the richest income quintiles would avert more DALYs than those in the poorest quintiles. For both programmes, most cases of CHE would be averted by individuals in the poorest income quintile. Programme B would avert the most CHE cases overall and females would have a greater share of benefits. All cases of impoverishing medical expenditure would be averted by individuals in the poorest quintile (A: 115 cases and B: 493 cases) for both programmes. The cost to avert each case of CHE with Programme A ranged from $67 to $292 and $100 to $232 for Programme B. We found a pro-rich health distribution and a pro-poor CHE distribution associated with eliminating out-of-pocket costs of cataract surgery in Vietnam. A programme that addressed both medical and non-medical out-of-pocket costs could have the greatest impact on improving financial protection in this population, particularly among the poorest income quintiles and for females. This study supports the concordance between the objectives of UHC and gender equity.

Socio-economic disparity in global burden of near vision loss: an analysis for 2017 with time trends since 1990

PURPOSE

To investigate the socio-economic disparity in global burden of near vision loss by disability-adjusted life-years (DALYs).

METHODS

The DALY numbers of country income groups by World Bank classification and the national age-standardized DALY rates caused by near vision loss were obtained from Global Burden of Disease Study 2017. Human development index (HDI) was collected from the Human Development Report. The association between age-standardized DALY rates and HDI was analysed. Additionally, the concentration index (CI) and the relative index of inequality (RII) were employed to assess the trends of socio-economic disparity in the global burden of near vision loss from 1990 to 2017.

RESULTS

The global burden of near vision loss increased from 5.3 million DALYs in 1990 to 9.8 million DALYs in 2017, corresponding to an increase of 82.4%. The highest rate of increase for 1990-2017 occurred in low-income country group (97.7%). Age-standardized DALY rates were inversely correlated with HDI (Standardized β = -0.679, P < 0.001). Lower HDI countries displayed higher age-standardized DALY rates caused by near vision loss. From 1990 to 2017, CI declined from -0.233 to -0.209, and RII increased from 0.149 to 0.247.

CONCLUSION

The total global burden of near vision loss increased greatly in the past few decades, with low-income countries showing the highest growth. The age-standardized burden was higher in countries with lower socio-economic status. Although a declining trend of socio-economic inequalities was observed, the persistence of disparities still highlights the need to provide more eye care services for developing countries.

The Impact of Sociodemographic and Socioeconomic Factors on the Burden of Cataract in Small Island Developing States (SIDS) in the Caribbean from 1990 to 2016

Purpose: To study the impact of sociodemographic and socioeconomic factors on the cataract burden in Caribbean small island developing states (SIDS) using disability-adjusted life-years (DALYs).Methods: National and regional age and sex specific cataract DALY numbers and rates from 1990 to 2016 for Caribbean SIDS, were extracted from the Global Burden of Disease Study 2016. The human development index (HDI), healthcare access and quality (HAQ) index, and the World Bank's classification of economies were used as socioeconomic status indicators. The Gini coefficient, Atkinson, Theil and concentration indices were used to measure health inequality. Paired Wilcoxon signed rank test, Pearson correlation, and linear regression analyses were performed to evaluate the sociodemographic and socioeconomic factors associated with differences in cataract burden.Results: Men had higher age-standardized DALY rates than women (P < .001) with median rates of 90.72 (Interquartile range [IQR], 87.8-94.2) and 83.94(IQR, 80.9-86.5), respectively. The burden of cataract increased with age. Upper-middle income countries had higher age-standardized DALY rates than high income countries (P < .001), with median rates of 90.1 (IQR, 86.8-93.4) and 79.8 (IQR, 77.5-81.8), respectively. Age-standardized DALY rates were inversely correlated with HDI (r = - 0.61, β = - 51.56 [P < .05]) and HAQ (r = - 0.68, β = - 0.46 [P < .01). Between-country inequality was negligible, and the burden of cataract is greater among the poor.Conclusion: Global trends of socioeconomic factors were confirmed. Significantly, men had higher age-standardized DALY rates than women. This is an area for further research.

Vision Impairment and Receipt of Eye Care Among Older Adults in Low- and Middle-Income Countries

Importance

Vision impairment (VI), including blindness, affects hundreds of millions globally, and 90% of those with VI live in low- and middle-income countries. Cross-national comparisons are important to elucidate the unique and shared factors associated with VI and receipt of eye care in different countries and to target those most in need.

Objective

To identify the characteristics associated with VI and receipt of eye care in a sample of low- and middle-income countries.

Design, Setting, and Participants

In this study of cross-sectional survey data from wave 1 of the World Health Organization Study on Global Aging and Adult Health, data on sociodemographic characteristics and health were collected from nationally representative samples in China, Ghana, India, Mexico, Russia, and South Africa from 2007 to 2010. Probability sampling with multistage, stratified, random-cluster samples was used to identify households and participants. The survey was completed by 34 159 adults 50 years and older. Data were analyzed from December 2017 to February 2018.

Main Outcomes and Measures

We analyzed associations of individual-level and household-level covariates with 3 primary outcomes: distance VI (visual acuity worse than 6/18 in the better-seeing eye), near VI (visual acuity worse than 6/18 in the better-seeing eye), and receipt of an eye examination within the previous 2 years.

Results

The study sample in China consisted of 13 350 participants (50.2% female; mean [SD] age, 62.6 [9.0] years); in Ghana, 4725 participants (50.4% female; mean [SD] age, 64.2 [10.8] years); in India, 7150 participants (48.9% female; mean [SD] age, 61.5 [9.0] years); in Mexico, 2103 participants (52.3% female; mean [SD] age, 69.2 [9.2] years); in Russia, 3763 participants (61.1% female; mean [SD] age, 63.9 [10.4] years); and in South Africa, 3838 participants (55.9% female; mean [SD] age 61.6 [9.5]) (all demographic characteristics weighted to reflect respective populations). The weighted proportion of the study sample with distance VI ranged from 9.9% (95% CI, 9.3-10.5) in China to 25.4% (95% CI, 22.0-29.2) in Russia; near VI, from 28.5% (95% CI, 26.9-30.1) in Ghana to 43.1% (95% CI, 41.1-45.1) in India; and receipt of a recent eye examination, from 15.0% (95% CI, 13.8-16.2) in Ghana to 53.1% (95% CI, 49.3-56.8) in Russia. Educational attainment, medical comorbidities, and memory were significantly associated with all outcomes across most low- and middle-income countries. Female sex, low household wealth, food insecurity, no health insurance, rurality, disability, being unmarried, and low social participation were significantly associated with adverse vision-related outcomes, though less consistently.

Conclusions and Relevance

There are both common and unique characteristics associated with VI and receipt of eye care across low- and middle-income countries. Our findings suggest that recognizing these factors is important to identify those most at risk and allocate resources optimally. Additional local epidemiological studies are needed.

Horizontal inequity in the utilization of cataract surgery in Iran: Shahroud Eye Cohort Study, 2009-2014

Background: Since there was no evidence about economic inequity in utilization of cataract surgery in developing countries, such as Iran, this study was designed to measure horizontal inequity in the utilization of cataract surgery and its changes in an Iranian middleaged population in 2009 and 2014. Methods: Using data from the first and second phases of Shahroud Eye Cohort Study (2009-2014), the economic inequity in the utilization of cataract surgery in an Iranian middle-aged population aged 40-64 years in 2009 and 2014 was evaluated. The horizontal inequity index (HI) was determined using the indirect standardization method based on a nonlinear (probit) model and the concentration index (C) was decomposed into the contribution of each factor. The analyses were performed using STATA software version 12/SE, and significance level was set at less than 0.05. Results: The HI in the utilization of cataract surgery increased from 0.080 (95% CI: 0.011-0.098) in 2009 to 0.166 (95% CI: 0.0821- 0.228) in 2014. Decomposition of changes in the concentration index showed that among need and non-need variables, older age and economic status (being among the wealthiest 20%) were the greatest contributors, with shares of 67.5% and 57.5%%, respectively, which led to pro-rich inequity during the study periods. Conclusion: The present study demonstrated that utilization of cataract surgery did not have an equal distribution among economic quintiles, despite considering equal needs based on cataract severity. Results demonstrated that older age and economic status were the greatest contributors to HI increase in 2009 and 2014.

Comparing low-cost handheld autorefractors: A practical approach to measuring refraction in low-resource settings

Purpose

To compare and validate the accuracy and ease of use of handheld autorefractors against retinoscopic refraction by an ophthalmologist for assessing the visual acuity of older adults in India.

Methods

190 patients were enrolled at the Sankara Eye Hospital in Bangalore, India, to undergo refraction using three different handheld devices—Retinomax (Nikon Inc., Japan), Netra (Eyenetra, Inc., USA), and QuickSee (PlenOptika, Inc., USA)—and the results were compared with cycloplegic retinoscopy and refraction done by an ophthalmologist. We analyzed the mean, standard deviation (S.D.), and Bland-Altman comparison of dioptric (D) power accuracy.

Results

The difference between the handheld devices and subjective refraction for each device was: Retinomax (N = 186), mean -0.41 D, S.D. 2.14; Netra (N = 179), mean 0.61 D, S.D. 2.20; and QuickSee (N = 182), mean -0.05 D, S.D. 1.04.

Conclusion

The QuickSee and the Retinomax may be used successfully as refraction screening tools in epidemiologic studies of adults in India and as diagnostic tools in low-resource settings.

Prevalence, Causes, and Factors Associated with Visual Impairment and Blindness among Registered Pensioners in Ghana

Purpose

To determine the prevalence, causes, and factors associated with presenting visual impairment and blindness among pensioners.

Design

A nationwide cross-sectional study. This study was part of the analysis on data obtained in the pensioners' medical survey conducted among members of the National Pensioners Association in Ghana.

Method

(i) Setting: it was a multicenter study involving thirteen centers throughout Ghana with a center in each regional capital. (ii) Study population: the study involved 4813 pensioners. (iii) Observation procedures: data were captured through the use of questionnaires, physical examinations including eye examinations, and urine and blood sample analysis. (iv) Main outcome measure: presenting visual impairment and blindness (as defined by the WHO ICD-10 classification).

Results

The overall prevalence of blindness among pensioners in Ghana was 3.8% (95% CI = 3.2–4.4), while the prevalence of moderate and severe visual impairment was 21.7% (95% CI = 20.5–23.0). The prevalence of blindness was lowest in the 60–65-year-old age group (2.1% (95% CI = 1.3–2.8)) and highest in the above 80-year-old age group (12.2% (95% CI = 6.6–17.8)). Cataract was the leading cause of blindness (62.4%) and moderate and severe visual impairment (55.7%). Factors significantly associated with blindness and visual impairment include educational status, vegetarianism, arthritis, and having proteins in urine.

Conclusion

There is a high prevalence of visual impairment and blindness among the pensioners in Ghana. Sadly, the greatest cause was cataract, which is correctable. Increase in formal education status will be important in the prevention of blindness and visual impairment.

Association of Sex With the Global Burden of Cataract

Importance

Eye disease burden could help guide health policy making. Differences in cataract burden by sex is a major concern of reducing avoidable blindness caused by cataract.

Objective

To investigate the association of sex with the global burden of cataract by year, age, and socioeconomic status using disability-adjusted life-years (DALYs).

Design, Setting, and Participants

This international, comparative burden-of-disease study extracted the global, regional, and national sex-specific DALY numbers, crude DALY rates, and age-standardized DALY rates caused by cataract by year and age from the Global Burden of Disease Study 2015. The DALY data were collected from January 1, 1990, through December 31, 2015, for ever 5 years. The human development index (HDI) in 2015 was extracted as an indicator of national socioeconomic status from the Human Development Report.

Main Outcomes and Measures

Comparisons of sex-specific DALY estimates due to cataract by year, age, and socioeconomic status at the global level. Paired Wilcoxon signed rank test, Pearson correlation, and linear regression analyses were performed to evaluate the socioeconomic-associated sex differences in cataract burden.

Results

Differences in rates of cataract by sex were similar between 1990 and 2015, with age-standardized DALY rates of 54.5 among men vs 65.0 among women in 1990 and 52.3 among men vs 67.0 among women in 2015. Women had higher rates than men of the same age, and sexual differences increased with age. Paired Wilcoxon signed rank test revealed that age-standardized DALY rates among women were higher than those among men for each HDI-based country group (z range, -4.236 to -6.093; P < .001). The difference (female minus male) in age-standardized DALY rates (r = -0.610 [P < .001]; standardized β = -0.610 [P < .001]) and the female to male age-standardized DALY rate ratios (r = -0.180 [P = .02]; standardized β = -0.180 [P = .02]) were inversely correlated with HDI.

Conclusions and Relevance

Although global cataract health care is progressing, sexual differences in cataract burden showed little improvement in the past few decades. Worldwide, women have a higher cataract burden than men. Older age and lower socioeconomic status are associated with greater differences in rates of cataract by sex. Our findings may enhance public awareness of sexual differences in global cataract burden and emphasize the importance of making sex-sensitive health policy to manage global vision loss caused by cataract.

Utilization of Secondary Eye Care Services in Western Kenya

Background: Eye care provision is currently insufficient to meet the population's eye health needs in Kenya. Many people remain unnecessarily visually impaired or at risk of becoming so due to treatable or preventable conditions. A lack of access and awareness of services are key barriers, in large part due to their being too few eye care providers in the health system for this unmet need. Methods: A hospital-based, retrospective analysis of patients who attended Kitale eye unit, Trans Nzoia County, Kenya from 1st January 2013 to 31st December 2015. Age and sex standardized hospital attendance rates by residence, age group, and sex were calculated for Trans Nzoia county and each subcounty. The changing trends in attendance rates were estimated by calculating the difference between base year and last year. Incidence rate ratios for attendance for each age-group, sex, and residence were estimated using a multivariable regression model. Results: 20,695 patients from the county were seen in Kitale Eye Unit in 2013, 2014 and 2015. In that period, 8.3% had either uncorrected refractive error, cataracts or glaucoma, the priority VISION2020 diseases, and 61.0% had allergic or other conjunctivitis or normal eyes, which could potentially be managed at primary eye care. During the study period, overall average annual attendance rate increased from 609 to 792 per 100, 000 population, incidence rate ratio (IRR) 1.30 (95% confidence interval (CI) 1.26-1.35). Attendance rates increased more in females than males (34.7% vs. 25.1%, respectively), IRR 1.07 (1.04-1.10). Attendance rates increased with increasing age, (highest among the elderly compared to the young). We found that in extreme age groups (>75 years and <15years) females were less likely to attend than males and there was reduced utilization from those based furthest from the hospital. Conclusion: Specialist eye services are heavily utilized by people with conditions that could be managed at the primary health care level. Barriers to accessing eye services were distance and gender, especially among the most vulnerable groups (young and the elderly). Integration of primary and secondary eye care services could lower barriers to essential eye care services to the population whilst lowering pressure on the limited specialist services by ensuring more appropriate utilization.

Rapid Assessment of Avoidable Blindness: looking back, looking forward

The Rapid Assessment of Avoidable Blindness, or RAAB, is a relatively simple and low-cost survey methodology to provide data on the prevalence and causes of visual loss. The aim of this article is to reflect on the achievements and challenges of RAAB, and to describe the future developments that are needed to ensure that it remains a relevant and widely used tool. To date, at least 331 RAABs have been undertaken in 79 countries, and these surveys provide an important source of information on visual loss at both the local and global level. A RAAB repository has been developed which includes the site and date of RAABs undertaken, and, where authors have agreed, the core indicators, reports or even raw data from the survey. This dataset has already been used for meta-analyses, and there are further opportunities for its use. Despite these achievements, there are core areas in which RAAB needs to be strengthened so that the full benefits of undertaking the survey can be reaped. Key developments of RAAB are underway, and will include greater use of mobile technologies using a cloud-based platform to enable both digital data collection, real-time survey reviews, reporting and analysis, and a greater emphasis on using the data for planning.

Blindness and eye disease in a Tibetan region of China: findings from a Rapid Assessment of Avoidable Blindness survey

Introduction

The only population-based survey of blindness and visual impairment of a Tibetan population was conducted in the Tibet Autonomous Region in 1999.

Methods and analysis

The Rapid Assessment of Avoidable Blindness methodology was used to conduct a survey of Kandze Tibetan Autonomous Prefecture, Sichuan Province of China in the Fall 2017. Using the 2010 census, 100 clusters of 50 participants aged 50 years or older were randomly sampled using probability proportionate to size.

Results

Among the 5000 people enumerated, 4763 were examined (95.3% response). The age-adjusted and sex-adjusted prevalence of blindness, severe visual impairment, moderate visual impairment and early visual impairment (EVI) were 1.6% (95% CI: 1.08 to 2.38)), 0.9% (95% CI:0.7 to 1.5), 5.1% (95% CI:4.4 to 5.7), and 7.45% (95% CI:6.67 to 8.2), respectively. The prevalence of blindness among Tibetans was significantly higher than that among Han Chinese (2.2% (95% CI:1.8 to 2.6) and 0.6 (95% CI:0.2 to 1.7), respectively, p<0.05). Women bore a significant excess burden of EVI compared with men (8.5% (95% CI:7.5 to 9.6) and 6.1% (95% CI:5.1 to 7.2), respectively, p<0.05). Cataract was the primary cause of blindness (39.4%) followed by macular degeneration (10.6%) and corneal opacity (5.3%).

Conclusion

Blindness and visual impairment in Kandze Tibetan Autonomous Prefecture is substantially less than an earlier study of a Tibetan region and now resembles other regions of China. About 58% of blindness and 67% of SVIwere avoidable, primarily by providing cataract services. Eighty-three percent of EVI was avoidable by providing refractice services throughout the region.

Evidence for national universal eye health plans

Many low- and middle-income countries use national eye-care plans to guide efforts to strengthen eye-care services. The World Health Organization recognizes that evidence is essential to inform these plans. We assessed how evidence was incorporated in a sample of 28 national eye-care plans generated since the Universal eye health: a global action plan 2014-2019 was endorsed by the World Health Assembly in 2013. Most countries (26, 93%) cited estimates of the prevalence of blindness and 18 countries (64%) had set targets for the cataract surgical rate in their plan. Other evidence was rarely cited or used to set measurable targets. No country cited evidence from systematic reviews or solution-based research. This limited use of evidence reflects its low availability, but also highlights incomplete use of existing evidence. For example, despite sex-disaggregated data and cataract surgical coverage being available from surveys in 20 countries (71%), these data were reported in the eye health plans of only nine countries (32%). Only three countries established sex-disaggregated indicators and only one country had set a target for cataract surgical coverage for future monitoring. Countries almost universally recognized the need to strengthen health information systems and almost one-third planned to undertake operational or intervention research. Realistic strategies need to be identified and supported to translate these intentions into action. To gain insights into how a country can strengthen its evidence-informed approach to eye-care planning, we reflect on the process underway to develop Kenya's seventh national plan (2019-2023).

Sex, gender and blindness: a new framework for equity

Four-fifths of all blind or vision impaired people live in middle-income and low-income countries with the African region and parts of Asia and the Middle East bearing the heaviest burden. At the same time, we know that around two thirds of all blind people in the world are female. Hence, the poorest (and usually the oldest) women are most likely to have their lives limited by visual impairment. While recent strategies have focussed on international variations in eye health, very few have paid attention to the gender differences that are an inextricable element in these inequalities. This review will explore possible explanations for the advantage of men in the exercise of one of the most basic of human senses. It will show that this cannot be understood through the use of a biomedical approach alone. Broader social perspectives will also be needed in order to create an appropriate knowledge base for tackling global inequalities in blindness.

Strengthening primary eye care in South Africa: An assessment of services and prospective evaluation of a health systems support package

Visual impairment is a significant public health concern, particularly in low- and middle-income countries where eye care is predominantly provided at the primary healthcare (PHC) level, known as primary eye care. This study aimed to perform an evaluation of primary eye care services in three districts of South Africa and to assess whether an ophthalmic health system strengthening (HSS) package could improve these services. Baseline surveys were conducted in Cape Winelands District, Johannesburg Health District and Mopani District at 14, 25 and 36 PHC facilities, respectively. Thereafter, the HSS package, comprising group training, individual mentoring, stakeholder engagement and resource provision, was implemented in 20 intervention sites in Mopani District, with the remaining 16 Mopani facilities serving as control sites. At baseline, less than half the facilities in Johannesburg and Mopani had dedicated eye care personnel or sufficient space to measure visual acuity. Although visual acuity charts were available in most facilities, <50% assessed patients at the correct distance. Median score for availability of nine essential drugs was <70%. Referral criteria knowledge was highest in Cape Winelands and Johannesburg, with poor clinical knowledge across all districts. Several HSS interventions produced successful outcomes: compared to control sites there was a significant increase in the proportion of intervention sites with eye care personnel and resources such as visual acuity charts (p = 0.02 and <0.01, respectively). However, engaging with district pharmacists did not improve availability of essential drugs (p = 0.47). Referral criteria knowledge improved significantly in intervention sites (p<0.01) but there was no improvement in clinical knowledge (p = 0.76). Primary eye care in South Africa faces multiple challenges with regard to organisation of care, resource availability and clinical competence. The HSS package successfully improved some aspects of this care, but further development is warranted together with debate regarding the positioning of eye services at PHC level.

Willingness to pay for cataract surgery is much lower than actual costs in Zamfara state, northern Nigeria

PURPOSE

Direct medical and non-medical costs incurred by those undergoing subsidised cataract surgery at Gusau eye clinic, Zamfara state, were recently determined. The aim of this study was to assess the willingness to pay for cataract surgery among adults with severe visual impairment or blindness from cataract in rural Zamfara and to compare this to actual costs.

METHODS

In three rural villages served by Gusau eye clinic, key informants helped identify 80 adults with bilateral severe visual impairment or blindness (<6/60), with cataract being the cause in at least one eye. The median amount participants were willing to pay for cataract surgery was determined. The proportion willing to pay actual costs of the (i) subsidised surgical fee (US$18.5), (ii) average non-medical expenses (US$25.2), and (iii) average total expenses (US$51.2) at Gusau eye clinic were calculated. Where participants would seek funds for surgery was determined.

RESULTS

Among 80 participants (38% women), most (n = 73, 91%) were willing to pay something, ranging from <US$1 to US$186 (median US$18.5, interquartile range 6.2-31.1). Approximately half of the participants (n = 41) were willing to pay US$18.5 (78% men), one-third (n = 26) were willing to pay US$25.2 (77% men); and 11% (n = 9) were willing to pay US$51.2 (all men). Only six participants (8%) already had the money to pay; one quarter (n = 20) would need to sell possessions to raise the funds.

CONCLUSION

Willingness to pay for cataract surgery among adults with operable cataract in rural Zamfara state is far lower than current costs of undergoing surgery. People who were widowed-most of whom were women-were willing to pay least. Further financial support is required for cataract surgery to be universally accessible.

Avoidable Waste in Ophthalmic Epidemiology: A Review of Blindness Prevalence Surveys in Low and Middle Income Countries 2000-2014

PURPOSE

Sources of avoidable waste in ophthalmic epidemiology include duplication of effort, and survey reports remaining unpublished, gaining publication after a long delay, or being incomplete or of poor quality. The aim of this review was to assess these sources of avoidable waste by examining blindness prevalence surveys undertaken in low and middle income countries (LMICs) between 2000 and 2014.

METHODS

On December 1, 2016 we searched MEDLINE, EMBASE and Web of Science databases for cross-sectional blindness prevalence surveys undertaken in LMICs between 2000 and 2014. All surveys listed on the Rapid Assessment of Avoidable Blindness (RAAB) Repository website ("the Repository") were also considered. For each survey we assessed (1) availability of scientific publication, survey report, summary results tables and/or datasets; (2) time to publication from year of survey completion and journal attributes; (3) extent of blindness information reported; and (4) rigour when information was available from two sources (i.e. whether it matched).

RESULTS

Of the 279 included surveys (from 68 countries) 186 (67%) used RAAB methodology; 146 (52%) were published in a scientific journal, 57 (20%) were published in a journal and on the Repository, and 76 (27%) were on the Repository only (8% had tables; 19% had no information available beyond registration). Datasets were available for 50 RAABs (18% of included surveys). Time to publication ranged from <1 to 11 years (mean, standard deviation 2.8 ± 1.8 years). The extent of blindness information reported within studies varied (e.g. presenting and best-corrected, unilateral and bilateral); those with both a published report and Repository tables were most complete. For surveys published and with RAAB tables available, discrepancies were found in reporting of participant numbers (14% of studies) and blindness prevalence (15%).

CONCLUSION

Strategies are needed to improve the availability, consistency, and quality of information reported from blindness prevalence surveys, and hence reduce avoidable waste.

Magnitude, temporal trends, and projections of the global prevalence of blindness and distance and near vision impairment: a systematic review and meta-analysis

BACKGROUND

Global and regional prevalence estimates for blindness and vision impairment are important for the development of public health policies. We aimed to provide global estimates, trends, and projections of global blindness and vision impairment.

METHODS

We did a systematic review and meta-analysis of population-based datasets relevant to global vision impairment and blindness that were published between 1980 and 2015. We fitted hierarchical models to estimate the prevalence (by age, country, and sex), in 2015, of mild visual impairment (presenting visual acuity worse than 6/12 to 6/18 inclusive), moderate to severe visual impairment (presenting visual acuity worse than 6/18 to 3/60 inclusive), blindness (presenting visual acuity worse than 3/60), and functional presbyopia (defined as presenting near vision worse than N6 or N8 at 40 cm when best-corrected distance visual acuity was better than 6/12).

FINDINGS

Globally, of the 7·33 billion people alive in 2015, an estimated 36·0 million (80% uncertainty interval [UI] 12·9-65·4) were blind (crude prevalence 0·48%; 80% UI 0·17-0·87; 56% female), 216·6 million (80% UI 98·5-359·1) people had moderate to severe visual impairment (2·95%, 80% UI 1·34-4·89; 55% female), and 188·5 million (80% UI 64·5-350·2) had mild visual impairment (2·57%, 80% UI 0·88-4·77; 54% female). Functional presbyopia affected an estimated 1094·7 million (80% UI 581·1-1686·5) people aged 35 years and older, with 666·7 million (80% UI 364·9-997·6) being aged 50 years or older. The estimated number of blind people increased by 17·6%, from 30·6 million (80% UI 9·9-57·3) in 1990 to 36·0 million (80% UI 12·9-65·4) in 2015. This change was attributable to three factors, namely an increase because of population growth (38·4%), population ageing after accounting for population growth (34·6%), and reduction in age-specific prevalence (-36·7%). The number of people with moderate and severe visual impairment also increased, from 159·9 million (80% UI 68·3-270·0) in 1990 to 216·6 million (80% UI 98·5-359·1) in 2015.

INTERPRETATION

There is an ongoing reduction in the age-standardised prevalence of blindness and visual impairment, yet the growth and ageing of the world's population is causing a substantial increase in number of people affected. These observations, plus a very large contribution from uncorrected presbyopia, highlight the need to scale up vision impairment alleviation efforts at all levels.

FUNDING

Brien Holden Vision Institute.

Inequality in cataract blindness and services: moving beyond unidimensional analyses of social position

OBJECTIVE

Inequalities in cataract blindness are well known, but data are rarely disaggregated to explore the combined effects of a range of axes describing social disadvantage. We examined inequalities in cataract blindness and services at the intersection of three social axes.

METHODS

Three dichotomous social variables (sex (male/female); place of residence (urban/rural); literacy (literate/illiterate)) from cross-sectional national blindness surveys in Pakistan (2001-2004; n=16 507) and Nigeria (2005-2007; n=13 591) were used to construct eight subgroups, with disadvantaged subgroups selected a priori (ie, women, rural dwellers, illiterate). In each data set, the social distribution of cataract blindness, cataract surgical coverage (CSC) and effective cataract surgical coverage (eCSC) were examined. Inequalities were assessed comparing the best-off and worst-off subgroups using rate differences and rate ratios (RRs). Logistic regression was used to assess cumulative effects of multiple disadvantage.

RESULTS

Disadvantaged subgroups experienced higher prevalence of cataract blindness, lower CSC and lower eCSC in both countries. A social gradient was present for CSC and eCSC, with coverage increasing as social position improved. Relative inequality in eCSC was approximately twice as high as CSC (Pakistan: eCSC RR 2.7 vs CSC RR 1.3; Nigeria: eCSC RR 8.7 vs CSC RR 4.1). Cumulative disadvantage was observed for all outcomes, deteriorating further with each additional axis along which disadvantage was experienced.

CONCLUSIONS

Each outcome tended to be worse with the addition of each layer of social disadvantage. Illiterate, rural women fared worst in both settings. Moving beyond unidimensional analyses of social position identified subgroups in most need; this permits a more nuanced response to addressing the inequitable distribution of cataract blindness.