Rapid Assessment Of Avoidable Blindness Survey Research Articles

Assessment of eye health programme reach by comparison with rapid assessment of avoidable blindness (RAAB) survey data, Talagang, Pakistan

BackgroundThe purpose of this study was to quantify how much of the burden of visual impairment (VI) and unmet need in Talagang, identified by Rapid Assessment of Avoidable Blindness (RAAB) survey data, has been addressed by Community Eye Health (CEH) programme efforts.MethodsA RAAB survey was carried out in November 2018, with 2,824 participants in Talagang Tehsil, Punjab, Pakistan, aged 50 and over. Census data were used to extrapolate survey data to the population. Alongside this, a CEH programme was launched, consisting of community eye screening, and onward referral to rural health centres, secondary or tertiary ophthalmological services, as required. This health intervention aimed to address the eye care needs surfaced by the initial survey. From 2018 to 2022, 30,383 people aged 50 or over were screened; 14,054 needed referral to further steps of the treatment pathway and more detailed data collection. Programme data were compared to estimates of population unmet needs. Main outcome measures were prevalence of VI, and proportion of need met by CEH Programme, by cause and level of VI.ResultsAmong those aged 50 and over, 51.0% had VI in at least one eye. The leading causes were cataract (46.2%) and uncorrected refractive error (URE) (25.0%). In its first four years, the programme reached an estimated 18.3% of the unmet need from cataract, and 21.1% of URE, equally in both men and women.ConclusionsRobustly collected survey and programme data can improve eye health planning, monitoring and evaluation, address inequities, and quantify the resources required for improving eye health. This study quantifies the time required to reach eye health needs at the community level.

The Rapid Assessment of Avoidable Blindness survey: Review of the methodology and protocol for the seventh version (RAAB7).

The Rapid Assessment of Avoidable Blindness (RAAB) is a population-based cross-sectional survey methodology used to collect data on the prevalence of vision impairment and its causes and eye care service indicators among the population 50 years and older. RAAB has been used for over 20 years with modifications to the protocol over time reflected in changing version numbers; this paper describes the latest version of the methodology-RAAB7. RAAB7 is a collaborative project between the International Centre for Eye Health and Peek Vision with guidance from a steering group of global eye health stakeholders. We have fully digitised RAAB, allowing for fast, accurate and secure data collection. A bespoke Android mobile application automatically synchronises data to a secure Amazon Web Services virtual private cloud when devices are online so users can monitor data collection in real-time. Vision is screened using Peek Vision's digital visual acuity test for mobile devices and uncorrected, corrected and pinhole visual acuity are collected. An optional module on Disability is available. We have rebuilt the RAAB data repository as the end point of RAAB7's digital data workflow, including a front-end website to access the past 20 years of RAAB surveys worldwide. This website ( https://www.raab.world) hosts open access RAAB data to support the advocacy and research efforts of the global eye health community. Active research sub-projects are finalising three new components in 2024-2025: 1) Near vision screening to address data gaps on near vision impairment and effective refractive error coverage; 2) an optional Health Economics module to assess the affordability of eye care services and productivity losses associated with vision impairment; 3) an optional Health Systems data collection module to support RAAB's primary aim to inform eye health service planning by supporting users to integrate eye care facility data with population data.

Cataract Blindness in Armenia: The Results of Nationwide Rapid Assessment of Avoidable Blindness (RAAB)

ABSTRACT Purpose This study assessed the prevalence of cataract blindness, cataract surgical coverage (CSC), effective CSC, visual outcome after cataract surgery, and barriers to cataract surgery in a population aged 50 years and older in Armenia using Rapid Assessment of Avoidable Blindness (RAAB) methodology. Methods The study sample included 2258 individuals aged 50 years and older who were randomly selected from 11 provinces of Armenia in 2019 following the RAAB methodology. The study team randomly selected 50 clusters, 50 people in each. The RAAB survey form was used to collect information on cataract blindness, visual outcome after cataract surgery, and barriers to cataract surgery. Results The mean age of the participants was 65.3 (SD = 9.9) ranging from 50 to 99. The majority of participants were women (65.6%). Age- and sex-adjusted prevalence of blindness due to all causes was 1.5%; of which 36.4% was bilaterally blind due to cataract. The CSC and effective CSC at a cataract surgical threshold of <6/12 were 55.1% and 24.4%, respectively. Good outcome was reported in 43.7% of eyes after cataract surgery, borderline in 37.2% of eyes, and poor outcome in 19.1%. The main barriers to cataract surgery included “cost,” “need not felt,” or “fear.” Conclusion The prevalence of cataract blindness in our study was higher compared to high-income regions and lower than estimates from South/Southeast Asia. This study suggests the urgent need to update the National Strategic Plan to prevent blindness in Armenia with a focus on improving the quality and coverage of cataract surgery.

Spectacle Coverage Rate After Cataract Surgery in an Urban Area in Indonesia.

Uncorrected refractive errors after cataract surgery contribute to visual impairments. The aim of this study was to investigate the spectacle coverage rate (SCR) following cataract surgery and its relationship with socioeconomic factors in an urban city in Indonesia. This population-based cross-sectional study was conducted in 2015 in Jakarta. The former participants of the Rapid Assessment of Avoidable Blindness (RAAB) survey had a history of cataract surgery and met either of the following criteria: (1) wore spectacles with presenting visual acuity (PVA) 6/12 or (2) had PVA less than 6/12 regardless of spectacle use but achieved the best visual acuity (BVA) 6/12 with pinhole correction. Of the 2998 participants of the RAAB survey, 173 (5.6%) (252 eyes) had a history of cataract surgery, among whom 53 (86 eyes) met our inclusion criteria. The SCR was 69.8% and was associated with age group, household income level, education level, and physicians' recommendation of spectacle wear. Participants who were of nonproductive age (80%), had the highest household income level (88.2%), the highest level of education (87.5%), and had been recommended for spectacle use by their physicians (80.9%) demonstrated higher SCR. Participants with the highest household income had the highest SCR. Patients who had received a physician's recommendation showed a higher SCR and were 26 times more likely to wear spectacles (odds ratio [OR] 25.99, 95% CI 2.59-260.10). There is an unmet need for refractive errors after cataract surgery. Factors such as household income levels and physician recommendations were predictive of spectacle wear.

Nationwide Rapid Assessment of Avoidable Blindness (RAAB) in Armenia

ABSTRACT Purpose This study aimed to estimate the prevalence and main causes of blindness and visual impairment in population aged 50 years and older in Armenia using Rapid Assessment of Avoidable Blindness (RAAB) methodology. Methods The study team randomly selected 50 clusters (each consisting of 50 people) from all 11 regions of Armenia. Data on participants’ demographics, presenting visual acuity, pinhole visual acuity, principal cause of presenting visual acuity, spectacle coverage, uncorrected refractive error (URE), and presbyopia were collected using the RAAB survey form. Four teams of trained eye care professionals completed data collection in 2019. Results Overall, 2,258 people of 50 years and older participated in the study. The age- and gender- adjusted prevalence of bilateral blindness, severe and moderate visual impairment were 1.5% (95% CI: 1.0–2.1), 1.6% (95% CI: 1.0–2.2) and 6.6% (95% CI: 5.5–7.7), respectively. The main causes of blindness were cataract (43.9%) and glaucoma (17.1%). About 54.6% and 35.3% of participants had URE and uncorrected presbyopia, respectively. The prevalence of bilateral blindness and functional low vision increased with age and was the highest in participants 80 years and older. Conclusion The rate of bilateral blindness was comparable with findings from countries that share similar background and confirmed that untreated cataract was the main cause of blindness. Given that cataract blindness is avoidable, strategies should be developed aiming to further increase the volume and quality of cataract care in Armenia.

Effective cataract surgical coverage in adults aged 50 years and older: estimates from population-based surveys in 55 countries

Cataract is the leading cause of blindness globally. Effective cataract surgical coverage (eCSC) measures the number of people in a population who have been operated on for cataract, and had a good outcome, as a proportion of all people operated on or requiring surgery. Therefore, eCSC describes service access (ie, cataract surgical coverage, [CSC]) adjusted for quality. The 74th World Health Assembly endorsed a global target for eCSC of a 30-percentage point increase by 2030. To enable monitoring of progress towards this target, we analysed Rapid Assessment of Avoidable Blindness (RAAB) survey data to establish baseline estimates of eCSC and CSC. In this secondary analysis, we used data from 148 RAAB surveys undertaken in 55 countries (2003-21) to calculate eCSC, CSC, and the relative quality gap (% difference between eCSC and CSC). Eligible studies were any version of the RAAB survey conducted since 2000 with individual participant survey data and census population data for people aged 50 years or older in the sampling area and permission from the study's principal investigator for use of data. We compared median eCSC between WHO regions and World Bank income strata and calculated the pooled risk difference and risk ratio comparing eCSC in men and women. Country eCSC estimates ranged from 3·8% (95% CI 2·1-5·5) in Guinea Bissau, 2010, to 70·3% (95% CI 65·8-74·9) in Hungary, 2015, and the relative quality gap from 10·8% (CSC: 65·7%, eCSC: 58·6%) in Argentina, 2013, to 73·4% (CSC: 14·3%, eCSC: 3·8%) in Guinea Bissau, 2010. Median eCSC was highest among high-income countries (60·5% [IQR 55·6-65·4]; n=2 surveys; 2011-15) and lowest among low-income countries (14·8%; [IQR 8·3-20·7]; n=14 surveys; 2005-21). eCSC was higher in men than women (148 studies pooled risk difference 3·2% [95% CI 2·3-4·1] and pooled risk ratio of 1·20 [95% CI 1·15-1·25]). eCSC varies widely between countries, increases with greater income level, and is higher in men. In pursuit of 2030 targets, many countries, particularly in lower-resource settings, should emphasise quality improvement before increasing access to surgery. Equity must be embedded in efforts to improve access to surgery, with a focus on underserved groups. Indigo Trust, Peek Vision, and Wellcome Trust.

Visual impairment and blindness caused by posterior segment diseases in Hungary in people aged 50 years and older

Introduction: Posterior segment diseases are the most common causes of blindness and visual impairment in devel-oped countries among people aged 50 years and older in Hungary. Objective: The purpose of this study was to estimate the prevalence of visual impairment and blindness caused by posterior segment diseases in the population aged 50 years and older in Hungary. Method: 105 census enumeration units were randomly selected with a probability proportional to size by the Hungar-ian Central Statistical Office. The standardised Rapid Assessment of Avoidable Blindness (RAAB) method was used. Participants underwent eye examination with a direct ophthalmoscope. Participants underwent visual acuity testing with a Snellen tumbling E-chart with or without a pinhole. Dilated fundus examination was performed in diabetic participants using an indirect binocular ophthalmoscope. Results: In total, 3523 (95.9%) out of 3675 eligible people were examined, of whom the prevalence of bilateral blind-ness and severe visual impairment was 0.7% and 0.2%, respectively. The most common causes of visual impairment caused by posterior segment diseases were age-related macular degeneration (1.419%), glaucoma (0.397%), diabetic retinopathy (0.341%) and rhegmatogenous retinal detachment (0.198%). The most common causes of blindness caused by posterior segment diseases were age-related macular degeneration (37.5%), glaucoma (16.7%), diabetic retinopathy (8.3%), high myopia (8.3%), rhegmatogenous retinal detachment (8.3%) and retinitis pigmentosa (8.3%). Conclusion: Prevalence of severe visual impairment and blindness caused by posterior segment diseases was lower compared to results of RAAB surveys in other countries. The frequency order of different posterior segment diseases was in line with developed countries. Availability of eye care should be improved and financing should be modernized due to the continuously increasing number of patients with age-related macular degeneration, glaucoma, diabetes and pathologic myopia.

Diagnostic Accuracy of Rapid Assessment of Avoidable Blindness: A Population-based Assessment

To evaluate the diagnostic accuracy of rapid assessment of avoidable blindness (RAAB). Population-based diagnostic accuracy study. A total of 2145 (95.3%, 2145/2250) subjects aged 50 years and older who participated in the RAAB survey were included. All the recruited participants underwent ophthalmic examination according to the RAAB protocol and then were reexamined with instruments in a mobile eye clinic set up in a village center on the same day. Examination in the mobile clinic included standardized visual acuity (VA) tests using logMAR charts, refraction, slit-lamp biomicroscopy, and dilated fundal examination with a binocular indirect ophthalmoscope. Blindness and economic blindness were defined as VA in the better-seeing eye <3/60 and <6/60, respectively. Visual impairment (VI) was defined as VA <6/18 in the better eye. The primary cause of blindness and VI was defined according to the cause of VI in the participant's better eye. The sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and area under the curve (AUC) of receiver operating characteristics of RAAB for detection of blindness and the principal causes of VI. A total of 1816 subjects (84.7%), including 686 men (37.8%) and 1130 women (62.2%), underwent ophthalmic examination in the mobile eye clinic. The mean (±standard deviation) age was 64.4 ± 9.6 years. The sensitivities, specificities, AUC, PLR, and NLR of RAAB were 90.3%, 99.3%, 0.948, 124.0, and 0.10, respectively, for detection of blindness (presenting visual acuity, PVA <3/60); 89.5%, 98.7%, 0.940, 69.2, and 0.11, respectively, for detection of economic blindness (PVA <6/60); and 90.3%, 97.7%, 0.940, 38.7, and 0.10, respectively, for detection of VI (PVA <6/18). The sensitivities, specificities, AUC, PLR, and NLR were 90.5%, 98.1%, 0.943, 48.1, and 0.10; and 60.4%, 98.7%, 0.796, 46.4, and 0.40 for detection of VI (PVA <6/18) owing to cataract and refractive error, respectively. The diagnostic performances of RAAB were high for detecting the prevalence of blindness, VI, and VI owing to cataract.

A Rapid Assessment of Avoidable Blindness in Southern Zambia

IntroductionA rapid assessment of avoidable blindness (RAAB) was conducted in Southern Zambia to establish the prevalence and causes of blindness in order to plan effective services and advocate for support for eye care to achieve the goals of VISION 2020: the right to sight.MethodsCluster randomisation was used to select villages in the survey area. These were further subdivided into segments. One segment was selected randomly and a survey team moved from house to house examining everyone over the age of 50 years. Each individual received a visual acuity assessment and simple ocular examination. Data was recorded on a standard proforma and entered into an established software programme for analysis.Results2.29% of people over the age of 50 were found to be blind (VA <3/60 in the better eye with available correction). The major cause of blindness was cataract (47.2%) with posterior segment disease being the next main cause (18.8%). 113 eyes had received cataract surgery with 30.1% having a poor outcome (VA <6/60) following surgery. Cataract surgical coverage showed that men (72%) received more surgery than women (65%).DiscussionThe results from the RAAB survey in Zambia were very similar to the results from a similar survey in Malawi, where the main cause of blindness was cataract but posterior segment disease was also a significant contributor. Blindness in this part of Zambia is mainly avoidable and there is a need for comprehensive eye care services that can address both cataract and posterior segment disease in the population if the aim of VISION 2020 is to be achieved. Services should focus on quality and gender equity of cataract surgery.

Estimating numbers of blind children for planning services: findings in Kilimanjaro, Tanzania

Aim:Childhood blindness is included in the VISION 2020 initiative. However, childhood blindness is rare, so there is limited population-based evidence to assist with the planning of services. We carried out...