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Tropical Data: Approach and Methodology as Applied to Trachoma Prevalence Surveys. Ophthalmic Epidemiol 2023; 30:544-560. [PMID: 38085791 PMCID: PMC10751062 DOI: 10.1080/09286586.2023.2249546] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 08/11/2023] [Indexed: 12/18/2023]
Abstract
PURPOSE Population-based prevalence surveys are essential for decision-making on interventions to achieve trachoma elimination as a public health problem. This paper outlines the methodologies of Tropical Data, which supports work to undertake those surveys. METHODS Tropical Data is a consortium of partners that supports health ministries worldwide to conduct globally standardised prevalence surveys that conform to World Health Organization recommendations. Founding principles are health ministry ownership, partnership and collaboration, and quality assurance and quality control at every step of the survey process. Support covers survey planning, survey design, training, electronic data collection and fieldwork, and data management, analysis and dissemination. Methods are adapted to meet local context and needs. Customisations, operational research and integration of other diseases into routine trachoma surveys have also been supported. RESULTS Between 29th February 2016 and 24th April 2023, 3373 trachoma surveys across 50 countries have been supported, resulting in 10,818,502 people being examined for trachoma. CONCLUSION This health ministry-led, standardised approach, with support from the start to the end of the survey process, has helped all trachoma elimination stakeholders to know where interventions are needed, where interventions can be stopped, and when elimination as a public health problem has been achieved. Flexibility to meet specific country contexts, adaptation to changes in global guidance and adjustments in response to user feedback have facilitated innovation in evidence-based methodologies, and supported health ministries to strive for global disease control targets.
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Measuring the Impact of Malaria on the Living Human Retina. Methods Mol Biol 2022; 2470:731-748. [PMID: 35881386 DOI: 10.1007/978-1-0716-2189-9_54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Retinal examination and imaging are relatively simple methods for studying the dynamic impact of cerebral malaria on the microcirculation of the central nervous system. Retina and brain are affected similarly by Plasmodium falciparum. Unlike the brain, the human retina can be directly observed using commercially available clinical instruments in the setting of a critical care unit, and this can be done repeatedly and non-invasively. Additional information about blood-tissue barriers can be gained from fluorescein angiography. Non-ophthalmologist clinician scientists are usually unfamiliar with ophthalmoscopy and retinal imaging, and some readers may feel that these techniques are beyond them. This chapter aims to quell these fears by providing a step-by-step description of how to examine and photograph the human retina in children with cerebral malaria.
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Trachoma in Viet Nam: results of 11 surveillance surveys conducted with the Global Trachoma Mapping Project. Ophthalmic Epidemiol 2019; 25:93-102. [PMID: 30806534 PMCID: PMC6444206 DOI: 10.1080/09286586.2018.1477964] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Purpose: Following interventions against trachoma in Viet Nam, impact surveys conducted in 2003–2011 suggested that trachoma was no longer a public health problem. In 2014, we undertook surveillance surveys to estimate prevalence of trachomatous inflammation—follicular (TF) and trichiasis. Methods: A population-based prevalence survey was undertaken in 11 evaluation units (EUs) encompassing 24 districts, using Global Trachoma Mapping Project methods. A two-stage cluster sampling design was used in each EU, whereby 20 clusters and 60 children per cluster were sampled. Consenting eligible participants (children aged 1–9 years and adults aged ≥50 years) were examined for trachoma. Results: A total of 9391 households were surveyed, and 20,185 participants (98.8% of those enumerated) were examined for trachoma. EU-level TF prevalence in 1–9-year-olds ranged from 0% to 1.6%. In one cluster (in Hà Giang Province), the percentage of children with TF was 10.3%. The overall pattern of cluster-level percentages of children with TF, however, was consistent with an exponential distribution, which would be consistent with trachoma disappearing. Among people aged ≥50 years, prevalence of trichiasis by EU ranged from 0% to 0.75%; these estimates are equivalent to 0–0.13% in all ages. The prevalence of trichiasis unknown to the health system among people aged ≥50 years, by EU, ranged from 0% to 0.17%, which is equivalent to 0–0.03% in all ages. Conclusion: Findings suggest that trachoma is no longer a public health problem in any of the 11 EUs surveyed. However, given the high proportion of children with TF in one cluster in Hà Giang Province, further investigations will be undertaken.
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Automated Detection of Malarial Retinopathy in Retinal Fundus Images obtained in Clinical Settings. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:5950-5953. [PMID: 30441691 DOI: 10.1109/embc.2018.8513603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Cerebral malaria (CM) is a life-threatening clinical syndrome associated with 5-10% of malarial infection cases, most prevalent in Africa. About 23% of cerebral malaria cases are misdiagnosed as false positives, leading to inappropriate treatment and loss of lives. Malarial retinopathy (MR) is a retinal manifestation of CM that presents with a highly specific set of lesions. The detection of MR can reduce the false positive diagnosis of CM and alert physicians to investigate for other possible causes of the clinical symptoms and apply a more appropriate clinical intervention of underlying diseases. In order to facilitate easily accessible and affordable means of MR detection, we have developed an automated software system that detects the retinal lesions specific to MR, whitening and hemorrhages, using retinal color fundus images. The individual lesion detection algorithms were combined into an MR detection model using partial least square classifier. The classifier model was trained and tested on retinal image dataset obtained from 64 patients presenting with clinical signs of CM (44 with MR, 20 without MR). The MR detection model yielded specificity of 92% and sensitivity of 68%, with an AUC of 0.82. The proposed MR detection system demonstrates potential for broad screening of MR and can be integrated with a low-cost and portable retinal camera, to provide a bed-side tool for confirming CM diagnosis.
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Achieving universal eye health coverage: planning and human resource lessons from trachoma. COMMUNITY EYE HEALTH 2018; 31:54. [PMID: 30220811 PMCID: PMC6134455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Prevalence of blindness and cataract surgical coverage in Narayani Zone, Nepal: a rapid assessment of avoidable blindness (RAAB) study. Br J Ophthalmol 2017; 102:291-294. [DOI: 10.1136/bjophthalmol-2017-310716] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 09/16/2017] [Accepted: 10/06/2017] [Indexed: 11/03/2022]
Abstract
BackgroundThe 1981 Nepal Blindness Survey first identified the Narayani Zone as one of the regions with the highest prevalence of blindness in the country. Subseuqently, a 2006 survey of the Rautahat District of the Narayani Zone found it to have the country’s highest blindness prevalence. This study examines the impact on blind avoidable and treatable eye conditions in this region after significant increase in eye care services in the past decade.MethodsThe rapid assessment of avoidable blindness (RAAB) methodology was used with mobile data collection using the mRAAB smartphone app. Data analysis was done using the standard RAAB software. Based on the 2011 census, 100 clusters of 50 participants aged 50 years or older were randomly sampled proportional to population size.ResultsOf the 5000 participants surveyed, 4771 (95.4%) were examined. The age-adjusted and sex-adjusted prevalence of bilateral blindness, severe visual impairment (SVI) and moderate visual impairment (MVI) were 1.2% (95% CI 0.9% to 1.5%), 2.5% (95% CI 2.0% to -3.0%) and 13.2% (95% CI 11.8% to 14.5%), respectively. Cataract remains the primary cause of blindness and SVI despite cataract surgery coverage (CSC) of 91.5% for VA<3/60. Women still account for two-thirds of blindness.ConclusionThe prevalence of blindness in people over the age of 50 years has decreased from 6.9% in 2006 to 1.2%, a level in keeping with the national average; however, significant gender inequity persists. CSC has improved but continues to favour men.
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The Eyes Have It-Or Do They? Am J Trop Med Hyg 2017; 96:1007-1008. [PMID: 28500807 PMCID: PMC5417186 DOI: 10.4269/ajtmh.17-0045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
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Magnitude and Determinants of the Ratio between Prevalence of Low Vision and Blindness in Rapid Assessment of Avoidable Blindness Surveys. Ophthalmic Epidemiol 2017; 24:287-293. [PMID: 28362137 DOI: 10.1080/09286586.2017.1283045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
PURPOSE To determine the magnitude and determinants of the ratio between prevalence of low vision and prevalence of blindness in rapid assessment of avoidable blindness (RAAB) surveys globally. METHODS Standard RAAB reports were downloaded from the repository or requested from principal investigators. Potential predictor variables included prevalence of uncorrected refractive error (URE) as well as gross domestic product (GDP) per capita, health expenditure per capita of the country across World Bank regions. Univariate and multivariate linear regression were used to investigate the correlation between potential predictor variables and the ratio. RESULTS The results of 94 surveys from 43 countries showed that the ratio ranged from 1.35 in Mozambique to 11.03 in India with a median value of 3.90 (Interquartile range 3.06;5.38). Univariate regression analysis showed that prevalence of URE (p = 0.04), logarithm of GDP per capita (p = 0.01) and logarithm of health expenditure per capita (p = 0.03) were significantly associated with the higher ratio. However, only prevalence of URE was found to be significant in multivariate regression analysis (p = 0.03). CONCLUSION There is a wide variation in the ratio of the prevalence of low vision to the prevalence of blindness. Eye care service utilization indicators such as the prevalence of URE may explain some of the variation across the regions.
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The Use of Key Informant Method for Identifying Children with Blindness and Severe Visual Impairment in Developing Countries. Ophthalmic Epidemiol 2017; 24:153-167. [PMID: 28287870 DOI: 10.1080/09286586.2016.1259637] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE An estimated 19 million children are visually impaired; of these, 1.4 million are irreversibly blind. A key challenge is to identify them early in life to benefit maximally from visual rehabilitation, and/or treatment. This aggregative review and structured literature analysis summarizes evidence of what it is about the key informant (KI) approach that works to identify children with blindness or severe visual impairment (B/SVI) in the community (for whom, to what extent, in what circumstances, in what respect, how and why). METHODS Peer-reviewed (PubMed, hand search) and grey literature (Google, World Health Organization website, academic theses, direct requests) were included, and methods and criteria used for identification, productivity (number of children referred per KI), accuracy of referrals (positive predictive value, PPV), age of children with B/SVI, KI definition, sex, information about cost and comparisons aggregated. RESULTS We included 31 documents describing 22 unique KI programs. Mostly KIs identified children with B/SVI in 1-3 weeks, i.e. "campaign mode." In 60%, KIs were community volunteers, others formal health sector workers (FHSW). Around 0.02-1.56 children per KI (median = 0.25) were successfully recruited. PPV ranged from 12 to 66%. In two studies comparing FHSWs and community KIs, the latter were 8 and 10 times more productive. CONCLUSION KIs working in campaign mode may provide an effective approach to identifying children with B/SVI in communities. Including identification of ocular problems and/or other impairments has been recommended. Research on factors that influence effectiveness and on whether KIs continue to contribute could inform programs.
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Automated Detection of Malarial Retinopathy in Digital Fundus Images for Improved Diagnosis in Malawian Children with Clinically Defined Cerebral Malaria. Sci Rep 2017; 7:42703. [PMID: 28198460 PMCID: PMC5309896 DOI: 10.1038/srep42703] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 01/12/2017] [Indexed: 11/09/2022] Open
Abstract
Cerebral malaria (CM), a complication of malaria infection, is the cause of the majority of malaria-associated deaths in African children. The standard clinical case definition for CM misclassifies ~25% of patients, but when malarial retinopathy (MR) is added to the clinical case definition, the specificity improves from 61% to 95%. Ocular fundoscopy requires expensive equipment and technical expertise not often available in malaria endemic settings, so we developed an automated software system to analyze retinal color images for MR lesions: retinal whitening, vessel discoloration, and white-centered hemorrhages. The individual lesion detection algorithms were combined using a partial least square classifier to determine the presence or absence of MR. We used a retrospective retinal image dataset of 86 pediatric patients with clinically defined CM (70 with MR and 16 without) to evaluate the algorithm performance. Our goal was to reduce the false positive rate of CM diagnosis, and so the algorithms were tuned at high specificity. This yielded sensitivity/specificity of 95%/100% for the detection of MR overall, and 65%/94% for retinal whitening, 62%/100% for vessel discoloration, and 73%/96% for hemorrhages. This automated system for detecting MR using retinal color images has the potential to improve the accuracy of CM diagnosis.
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Abstract
Purpose: Population-based prevalence surveys were undertaken to determine whether trachoma is a public health problem in Laos requiring implementation of the SAFE strategy (surgery, antibiotics, facial cleanliness, environmental improvement). Methods: The country was divided into 19 evaluation units (EUs), each containing a population of roughly 100,000–350,000 people. Of these, 16 were believed most likely to harbor trachoma (based on historical evidence), and were mapped using the Global Trachoma Mapping Project methods. A 2-stage cluster sampling was used to sample approximately 1222 children aged 1–9 years in each EU, as well as all adults aged 15 years and older resident in households with children. The presence or absence of trachomatous inflammation – follicular (TF) and of trichiasis was documented in each subject, and prevalences (adjusted for age and sex) estimated. Results: The adjusted prevalence of TF in 1–9-year-olds ranged from 0.2% to 2.2% across the 16 EUs. Adjusted all-ages prevalence of trichiasis was 0.00% in 13 EUs, 0.06% in two EUs, and 0.12% in one EU. The trichiasis prevalence in adults in the last EU was 0.19%. Conclusions: The assessment included all areas of Laos suspected of ever harboring trachoma and most of the rural population of the country. The low prevalence of TF and trichiasis do not warrant any special programs against trachoma at this time.
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Prevention of blindness in leprosy: an overview of the relevant clinical and programme-planning issues. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2016. [DOI: 10.1080/00034983.1997.11813148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Safety of lumbar puncture in comatose children with clinical features of cerebral malaria. Neurology 2016; 87:2355-2362. [PMID: 27794112 PMCID: PMC5135026 DOI: 10.1212/wnl.0000000000003372] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 08/17/2016] [Indexed: 11/15/2022] Open
Abstract
Objective: We assessed the independent association of lumbar puncture (LP) and death in Malawian children admitted to the hospital with the clinical features of cerebral malaria (CM). Methods: This was a retrospective cohort study in Malawian children with clinical features of CM. Allocation to LP was nonrandom and was associated with severity of illness. Propensity score–based analyses were used to adjust for this bias and assess the independent association between LP and mortality. Results: Data were available for 1,075 children: 866 (80.6%) underwent LP and 209 (19.4%) did not. Unadjusted mortality rates were lower in children who underwent LP (15.3% vs 26.7% in the no-LP group) but differences in covariates between the 2 groups suggested bias in LP allocation. After propensity score matching, all covariates were balanced. Propensity score–based analyses showed no change in mortality rate associated with LP: by inverse probability weighting, the average risk reduction was 2.0% at 12 hours (95% confidence interval −1.5% to 5.5%, p = 0.27) and 1.7% during hospital admission (95% confidence interval −4.5% to 7.9%, p = 0.60). Undergoing LP did not change the risk of mortality in subanalyses of children with severe brain swelling on MRI or in those with papilledema. Conclusion: In comatose children with suspected CM who were clinically stable, we found no evidence that LP increases mortality, even in children with objective signs of raised intracranial pressure.
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Abstract
Purpose: To determine whether trachoma is a public health problem requiring intervention in Cambodia. Methods: Based on historical evidence and reports, 14 evaluation units (EUs) in Cambodia, judged to be most likely to harbor trachoma, were selected. The Global Trachoma Mapping Project methodology was used to carry out rigorous surveys to determine the prevalence of trachomatous inflammation–follicular (TF) and trichiasis in each EU. Results: The EU-level prevalence of TF among 25,801 1–9-year-old children examined ranged from 0% to 0.2%. Among the 24,502 adults aged 15+ years examined, trichiasis was found in 59 people. Age- and sex-adjusted prevalences of trichiasis in all ages in the EUs studied ranged from 0% to 0.14%; five EUs had a prevalence of trichiasis ≥0.1%. Conclusions: There appears to be no need nor justification at this time for implementing public health measures to control trachoma in Cambodia.
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Setting targets for human resources for eye health in sub-Saharan Africa: what evidence should be used? HUMAN RESOURCES FOR HEALTH 2016; 14:11. [PMID: 26984773 PMCID: PMC4794905 DOI: 10.1186/s12960-016-0107-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 03/09/2016] [Indexed: 05/13/2023]
Abstract
With a global target set at reducing vision loss by 25% by the year 2019, sub-Saharan Africa with an estimated 4.8 million blind persons will require human resources for eye health (HReH) that need to be available, appropriately skilled, supported, and productive. Targets for HReH are useful for planning, monitoring, and resource mobilization, but they need to be updated and informed by evidence of effectiveness and efficiency. Supporting evidence should take into consideration (1) ever-changing disease-specific issues including the epidemiology, the complexity of diagnosis and treatment, and the technology needed for diagnosis and treatment of each condition; (2) the changing demands for vision-related services of an increasingly urbanized population; and (3) interconnected health system issues that affect productivity and quality. The existing targets for HReH and some of the existing strategies such as task shifting of cataract surgery and trichiasis surgery, as well as the scope of eye care interventions for primary eye care workers, will need to be re-evaluated and re-defined against such evidence or supported by new evidence.
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Abstract
Purpose: To complete the baseline trachoma map worldwide by conducting population-based surveys in an estimated 1238 suspected endemic districts of 34 countries. Methods: A series of national and sub-national projects owned, managed and staffed by ministries of health, conduct house-to-house cluster random sample surveys in evaluation units, which generally correspond to “health district” size: populations of 100,000–250,000 people. In each evaluation unit, we invite all residents aged 1 year and older from h households in each of c clusters to be examined for clinical signs of trachoma, where h is the number of households that can be seen by 1 team in 1 day, and the product h × c is calculated to facilitate recruitment of 1019 children aged 1–9 years. In addition to individual-level demographic and clinical data, household-level water, sanitation and hygiene data are entered into the purpose-built LINKS application on Android smartphones, transmitted to the Cloud, and cleaned, analyzed and ministry-of-health-approved via a secure web-based portal. The main outcome measures are the evaluation unit-level prevalence of follicular trachoma in children aged 1–9 years, prevalence of trachomatous trichiasis in adults aged 15 + years, percentage of households using safe methods for disposal of human feces, and percentage of households with proximate access to water for personal hygiene purposes. Results: In the first year of fieldwork, 347 field teams commenced work in 21 projects in 7 countries. Conclusion: With an approach that is innovative in design and scale, we aim to complete baseline mapping of trachoma throughout the world in 2015.
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Abstract
Purpose: To determine the prevalence of trachoma in all suspected endemic districts in Malawi. Methods: A population-based survey conducted in 16 evaluation units from 12 suspected endemic districts in Malawi (population 6,390,517), using the standardized Global Trachoma Mapping Project (GTMP) protocol. A 2-stage cluster-random sampling design selected 30 households from each of 30 clusters per evaluation unit; all residents aged 1 year and older in selected households were examined for evidence of follicular trachoma (TF), intense trachomatous inflammation (TI), and trachomatous trichiasis (TT). Results: Four of the 16 evaluation units were found to be endemic for trachoma, with a prevalence range of 10.0–13.5% for TF and 0.2–0.6% for TT. Nine evaluation units had a TF prevalence between 5.0% and 9.9% while three evaluation units had a TF prevalence <5.0%. Conclusion: The prevalence rates of active trachoma in Malawi were not uniform among suspected endemic evaluation units, with rates higher than the World Health Organization (WHO) threshold for implementation of community-based control measures (TF ≥ 10.0%) in only 4 of the 16 evaluation units. Trachoma remains a disease of public health importance in some parts of Malawi and adjoining (unmapped) districts should be prioritized for mapping. According to the survey, an additional 3,169,362 people require intervention to reduce active disease and 1557 trichiasis surgeries are needed to reduce the prevalence of TT below WHO recommended thresholds.
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Task Shifting for Eye Care in Eastern Africa: General Nurses as Trichiasis Surgeons in Kenya, Malawi, and Tanzania. Ophthalmic Epidemiol 2016; 22:226-30. [PMID: 26158581 DOI: 10.3109/09286586.2015.1040924] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE There are approximately 8 million people with trachomatous trichiasis globally; in the year 2009, less than 160,000 people had surgery. These numbers are too low in order to achieve the goal of elimination of blinding trachoma by the year 2020. Task shifting approaches have led to the training of general nurses in trichiasis surgery in eastern Africa. The overall aim of this study was to determine the attrition and productivity (and the factors associated with productivity) of trichiasis surgeons in Kenya, Tanzania, and Malawi. METHODS A 3-year cohort study of trichiasis surgeons. RESULTS The overall response rate was 86%. Defining high productivity as 50+ operations per year per surgeon, only 16.1% of the trichiasis surgeons were highly productive. Among the surgeons, 27.9% were no longer at their site and ceased providing surgery (attrition) over the 3 years of study. High productivity was associated with having been trained by an experienced trainer, supervised by a clinical officer, having more than three surgical sets, and having an outreach program. CONCLUSION Attrition of general nurses trained in trichiasis surgery was high. Surgical productivity of trichiasis surgeons remained too low. It is likely that other approaches are needed to address the burden of trichiasis in the three countries. In terms of recommendations, training of trichiasis surgeons should be done in a "package," including a plan for provision of surgical equipment, continuous support and supervision, and outreach.
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Comparison of the effectiveness of three retinal camera technologies for malarial retinopathy detection in Malawi. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2016; 9693. [PMID: 31662595 DOI: 10.1117/12.2213282] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The purpose of this study was to test the suitability of three available camera technologies (desktop, portable, and i-phone based) for imaging comatose children who presented with clinical symptoms of malaria. Ultimately, the results of the project would form the basis for a design of a future camera to screen for malaria retinopathy (MR) in a resource challenged environment. The desktop, portable, and i-phone based cameras were represented by the Topcon, Pictor Plus, and Peek cameras, respectively. These cameras were tested on N=23 children presenting with symptoms of cerebral malaria (CM) at a malaria clinic, Queen Elizabeth Teaching Hospital in Malawi, Africa. Each patient was dilated for binocular indirect ophthalmoscopy (BIO) exam by an ophthalmologist followed by imaging with all three cameras. Each of the cases was graded according to an internationally established protocol and compared to the BIO as the clinical ground truth. The reader used three principal retinal lesions as markers for MR: hemorrhages, retinal whitening, and vessel discoloration. The study found that the mid-priced Pictor Plus hand-held camera performed considerably better than the lower price mobile phone-based camera, and slightly the higher priced table top camera. When comparing the readings of digital images against the clinical reference standard (BIO), the Pictor Plus camera had sensitivity and specificity for MR of 100% and 87%, respectively. This compares to a sensitivity and specificity of 87% and 75% for the i-phone based camera and 100% and 75% for the desktop camera. The drawback of all the cameras were their limited field of view which did not allow complete view of the periphery where vessel discoloration occurs most frequently. The consequence was that vessel discoloration was not addressed in this study. None of the cameras offered real-time image quality assessment to ensure high quality images to afford the best possible opportunity for reading by a remotely located specialist.
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Abstract
BACKGROUND Malarial retinopathy is an important finding in Plasmodium falciparum cerebral malaria, since it strengthens diagnostic accuracy, predicts clinical outcome and appears to parallel cerebral disease processes. Several angiographic features of malarial retinopathy have been described, but observations in different populations can only be reliably compared if consistent methodology is used to capture and grade retinal images. Currently no grading scheme exists for fluorescein angiographic features of malarial retinopathy. METHODS A grading scheme for fluorescein angiographic images was devised based on consensus opinion of clinicians and researchers experienced in malarial retinopathy in children and adults. Dual grading were performed with adjudication of admission fluorescein images from a large cohort of children with cerebral malaria. RESULTS A grading scheme is described and standard images are provided to facilitate future grading studies. Inter-grader agreement was >70 % for most variables. Intravascular filling defects are difficult to grade and tended to have lower inter-grader agreement (>57 %) compared to other features. CONCLUSIONS This grading scheme provides a consistent way to describe retinal vascular damage in paediatric cerebral malaria, and can facilitate comparisons of angiographic features of malarial retinopathy between different patient groups, and analysis against clinical outcomes. Inter-grader agreement is reasonable for the majority of angiographic signs. Dual grading with expert adjudication should be used to maximize accuracy.
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Factors affecting cataract surgical coverage and outcomes: a retrospective cross-sectional study of eye health systems in sub-Saharan Africa. BMC Ophthalmol 2015; 15:67. [PMID: 26122748 PMCID: PMC4485868 DOI: 10.1186/s12886-015-0063-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 06/23/2015] [Indexed: 10/25/2022] Open
Abstract
BACKGROUND Recently there has been a great deal of new population based evidence on visual impairment generated in sub-Saharan Africa (SSA), thanks to the Rapid Assessment of Avoidable Blindness (RAAB) survey methodology. The survey provides information on the magnitude and causes of visual impairment for planning services and measuring their impact on eye health in administrative "districts" of 0.5-5 million people. The survey results describing the quantity and quality of cataract surgeries vary widely between study sites, often with no obvious explanation. The purpose of this study was to examine health system characteristics that may be associated with cataract surgical coverage and outcomes in SSA in order to better understand the determinants of reducing the burden of avoidable blindness due to cataract. METHODS This was a descriptive study using secondary and primary data. The outcome variables were collected from existing surveys. Data on potential district level predictor variables were collected through a semi-structured tool using routine data and key informants where appropriate. Once collected the data were coded and analysed using statistical methods including t-tests, ANOVA and the Kruskal-Wallis analysis of variance test. RESULTS Higher cataract surgical coverage was positively associated with having at least one fixed surgical facility in the area; availability of a dedicated operating theatre; the number of surgeons per million population; and having an eye department manager in the facility. Variables that were associated with better outcomes included having biometry and having an eye department manager in the facility. CONCLUSIONS There are a number of health system factors at the district level that seem to be associated with both cataract surgical coverage and post-operative visual acuity outcomes. This study highlights the needs for better indicators and tools by which to measure and monitor the performance of eye health systems at the district level. It is unlikely that epidemiological data alone is sufficient for planning eye health services within a district and health managers and study coordinators need to consider collecting supplementary information in order to ensure appropriate planning can take place.
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A cost analysis of pediatric cataract surgery at two child eye health tertiary facilities in Africa. J AAPOS 2014; 18:559-62. [PMID: 25454021 PMCID: PMC4268264 DOI: 10.1016/j.jaapos.2014.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 06/18/2014] [Accepted: 08/03/2014] [Indexed: 10/24/2022]
Abstract
PURPOSE To determine the direct cost of pediatric cataract surgery at two child eye health tertiary facilities (CEHTFs) in Africa. METHODS The direct cost of pediatric cataract surgery was determined by reviewing data collected from two CEHTFs in Zambia and Malawi. Inventory, cost, and usage data of all durable medical equipment, consumable equipment, personnel, and medications were collected and the direct cost per child calculated. RESULTS For cataract surgery and related treatment during 2011, the total cost per child was calculated to be $202 for Malawi and $277 for Zambia using figures derived from estimating labor cost allocation proportional to employee time devoted to pediatric cataract management. The one-time equipment cost totaled $178,121 for Malawi and $179,832 for Zambia. CONCLUSIONS These cost estimates may serve as a basis for economic decisions aimed at improving access to care, management, and follow-up for children with cataract and provide useful insights for programs dedicated to promoting organizational and financial sustainability for CEHTFs in Africa.
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Training clinicians treating HIV to diagnose cytomegalovirus retinitis. Bull World Health Organ 2014; 92:903-8. [PMID: 25552774 PMCID: PMC4264397 DOI: 10.2471/blt.14.142372] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 06/05/2014] [Accepted: 08/07/2014] [Indexed: 12/16/2022] Open
Abstract
PROBLEM Acquired immunodeficiency syndrome (AIDS)-related cytomegalovirus (CMV) retinitis continues to be a neglected source of blindness in resource-poor settings. The main issue is lack of capacity to diagnose CMV retinitis in the clinical setting where patients receive care and all other opportunistic infections are diagnosed. APPROACH We developed and implemented a four-day workshop to train clinicians working in human immunodeficiency virus (HIV) clinics how to perform binocular indirect ophthalmoscopy and diagnose CMV retinitis. Workshops comprised both classroom didactic instruction and direct clinical eye examinations in patients with advanced AIDS. Between 2007 and 2013, 14 workshops were conducted in China, Myanmar and the Russian Federation. LOCAL SETTING Workshops were held with local clinicians at HIV clinics supported by nongovernmental organizations, public-sector municipal hospitals and provincial infectious disease referral hospitals. Each setting had limited or no access to locally- trained ophthalmologists, and an HIV-infected population with advanced disease. RELEVANT CHANGES Clinicians learnt how to do binocular indirect ophthalmoscopy and to diagnose CMV retinitis. One year after the workshop, 32/38 trainees in Myanmar did systematic eye examination for early diagnosis of CMV retinitis as standard care for at-risk patients. In China and the Russian Federation, the success rates were lower, with 10/15 and 3/5 trainees, respectively, providing follow-up data. LESSONS LEARNT Skills necessary for screening and diagnosis of CMV retinitis can be taught in a four-day task-oriented training workshop. Successful implementation depends on institutional support, ongoing training and technical support. The next challenge is to scale up this approach in other countries.
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Abstract
Most industrialized countries and many emerging economies have chosen to define 'blindness' at a visual acuity above that which WHO uses. This reflects the increasing visual demands of modern society for tasks such as driving or using cell phones. Meeting these demands will require more highly skilled health workers using more sophisticated equipment than has generally been considered sufficient for primary eye care.
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Abstract
Purpose: To assess the prevalence and causes of avoidable blindness in Atsinanana Region, Madagascar, with the Rapid Assessment of Avoidable Blindness (RAAB) survey. We analyzed the hospital records to supplement the findings for public health care planning. Materials and Methods: Only villages within a two-hour walk from a road, about half of the population of Atsinanana was included. Seventy-two villages were selected by population-proportional-to-size sampling. In each village, compact segment sampling was used to select 50 people over age 50 for eye examination using standard RAAB methods. Records at the two hospitals providing cataract surgery in the region were analyzed for information on patients who underwent cataract surgery in 2010. Cataract incidence rate and target cataract surgery rate (CSR) was modeled from age-specific prevalence of cataract. Results: The participation rate was 87% and the sample prevalence of blindness was 1.96%. Cataract was responsible for 64% and 85.7% of blindness and severe visual impairment, respectively. Visual impairment was due to cataract (69.4%) and refractive error (14.1%). There was a strong positive correlation between cataract surgical rate by district and the proportion of people living within 2 hours of a road. There were marked differences in the profiles of the cataract patients at the two facilities. The estimated incidence of cataract at the 6/18 level was 2.4 eyes per 100 people over age 50 per year. Conclusions: Although the survey included only people with reasonable access, the main cause of visual impairment was still cataract. The incidence of cataract is such that it ought to be possible to eliminate it as a cause of visual impairment, but changes in service delivery at hospitals and strategies to improve access will be necessary for this change.
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A randomised controlled trial to investigate effects of enhanced supervision on primary eye care services at health centres in Kenya, Malawi and Tanzania. BMC Health Serv Res 2014; 14 Suppl 1:S6. [PMID: 25079942 PMCID: PMC4108898 DOI: 10.1186/1472-6963-14-s1-s6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Background Knowledge and skills of primary health care workers (PHCWs) in primary eye care have been demonstrated to be inadequate in several districts of Kenya, Malawi, and Tanzania. We tested whether enhanced supervision, focused on improving practical skills over two years, would raise the scores of these workers on a test of basic knowledge and skills. Methods This was a randomised controlled trial. All primary health care (PHC) facilities within two districts of each country were enrolled and randomly assigned by district (Kenya, Malawi) or by health care facility (Tanzania) to receive quarterly skills-based supervision by a district eye coordinator or to continue existing routine supervision. At baseline, a test of basic knowledge and skills in five key areas was administered to PHCWs, and visual acuity (VA) charts and working torches were provided. After two years the test was administered again. Changes in test scores were compared between the intervention (enhanced supervision) and the non-intervention (routine supervision) facilities. Results All 137 facilities in the six districts were enrolled including 343 PHCWs. At baseline, no facility had a visual acuity chart and 18 (13%) had a working torch; the average total skills scores were 6.04 and 6.38 (maximum of 12) in the non-intervention and the intervention facilities, respectively. After two years, 16 intervention facilities (23.2%) had a visual acuity chart correctly placed and 19 (27.5%) had a working torch, compared to 4 (5.9%) and 6 (8.8%), respectively, in the routine supervision facilities. At the facility level, the change in overall test scores was +1.84 points in the intervention sites compared to +0.42 points in the non-intervention sites (p<0.001). Staff turnover included about 75% of the staff by the end of the study. Conclusion The improvements in the enhanced supervision facilities were very modest and of questionable clinical significance. The low impact of the intervention may be due to the high turnover of PHCWs or high absenteeism. A better understanding of the quality of eye care at PHC facilities and influencing factors are urgently needed before continuing to invest resources in the scale up of this model of task shifting in Africa.
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Skills of general health workers in primary eye care in Kenya, Malawi and Tanzania. HUMAN RESOURCES FOR HEALTH 2014; 12 Suppl 1:S2. [PMID: 25860909 PMCID: PMC4108885 DOI: 10.1186/1478-4491-12-s1-s2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
BACKGROUND Primary eye care (PEC) in sub-Saharan Africa usually means the diagnosis, treatment, and referral of eye conditions at the most basic level of the health system by primary health care workers (PHCWs), who receive minimal training in eye care as part of their curricula. We undertook this study with the aim to evaluate basic PEC knowledge and ophthalmologic skills of PHCWs, as well as the factors associated with these in selected districts in Kenya, Malawi, and Tanzania. METHODS A standardized (26 items) questionnaire was administered to PHCWs in all primary health care (PHC) facilities of 2 districts in each country. Demographic information was collected and an examination aimed to measure competency in 5 key areas (recognition and management of advanced cataract, conjunctivitis, presbyopia, and severe trauma plus demonstrated ability to measure visual acuity) was administered. RESULTS Three-hundred-forty-three PHCWs were enrolled (100, 107, and 136 in Tanzania, Kenya, and Malawi, respectively). The competency scores of PHCW varied by area, with 55.7%, 61.2%, 31.2%, and 66.1% scoring at the competency level in advanced cataract, conjunctivitis, presbyopia, and trauma, respectively. Only 8.2% could measure visual acuity. Combining all scores, only 9 (2.6%) demonstrated competence in all areas. CONCLUSION The current skills of health workers in PEC are low, with a large per cent below the basic competency level. There is an urgent need to reconsider the expectations of PEC and the content of training.
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Cataract incidence in sub-Saharan Africa: what does mathematical modeling tell us about geographic variations and surgical needs? Ophthalmic Epidemiol 2014; 20:260-6. [PMID: 24070099 DOI: 10.3109/09286586.2013.823215] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To apply a previously described mathematical model, designed to estimate cataract incidence from age-specific prevalence, to Rapid Assess of Avoidable Blindness survey data from Sub-Saharan Africa in order to estimate the incidence of cataract and therefore surgical needs. METHODS All Rapid Assessment of Avoidable Blindness surveys from Sub-Saharan Africa were identified. A previously developed mathematical model, designed to estimate the incidence of operable cataract was applied to those (27/32) meeting the inclusion criteria. RESULTS Incidence varied significantly across the continent with the result that cataract surgery rate targets required to eliminate cataract vary too. When variation in age structure is also taken into account, the cataract surgery rate needed to eliminate cataract visual impairment at the level of 6/18 ranges from 1200-4500 surgeries per year per million population. CONCLUSIONS This is important evidence of significant variation in the incidence of cataract within Sub-Saharan Africa. The variation may be related to genetic or cultural variations on the continent and has important implications for planning services.
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Task shifting for cataract surgery in eastern Africa: productivity and attrition of non-physician cataract surgeons in Kenya, Malawi and Tanzania. HUMAN RESOURCES FOR HEALTH 2014; 12 Suppl 1:S4. [PMID: 25859627 PMCID: PMC4108920 DOI: 10.1186/1478-4491-12-s1-s4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
BACKGROUND This project examined the surgical productivity and attrition of non-physician cataract surgeons (NPCSs) in Tanzania, Malawi, and Kenya. METHODS Baseline (2008-9) data on training, support, and productivity (annual cataract surgery rate) were collected from officially trained NPCSs using mailed questionnaires followed by telephone interviews. Telephone interviews were used to collect follow-up data annually on productivity and semi-annually on attrition. A detailed telephone interview was conducted if a surgeon left his/her post. Data were entered into and analysed using STATA. RESULTS Among the 135 NPCSs, 129 were enrolled in the study (Kenya 88, Tanzania 38, and Malawi 3) mean age 42 years; average time since completing training 6.6 years. Employment was in District 44%, Regional 24% or mission/ private 32% hospitals. Small incision cataract surgery was practiced by 38% of the NPCSs. The mean cataract surgery rate was 188/year, median 76 (range 0-1700). For 39 (31%) NPCSs their surgical rate was more than 200/year. Approximately 22% in Kenya and 25% in Tanzania had years where the cataract surgical rate was zero. About 11% of the surgeons had no support staff. CONCLUSIONS High quality training is necessary but not sufficient to result in cataract surgical activity that meets population needs and maintains surgical skill. Needed are supporting institutions and staff, functioning equipment and programs to recruit and transport patients.
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Is the cost the primary barrier for cataract surgery in Paraguay? Arq Bras Oftalmol 2014; 77:164-7. [DOI: 10.5935/0004-2749.20140042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 05/01/2014] [Indexed: 11/20/2022] Open
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Task shifting in primary eye care: how sensitive and specific are common signs and symptoms to predict conditions requiring referral to specialist eye personnel? HUMAN RESOURCES FOR HEALTH 2014; 12 Suppl 1:S3. [PMID: 25860992 PMCID: PMC4108919 DOI: 10.1186/1478-4491-12-s1-s3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
BACKGROUND The inclusion of primary eye care (PEC) in the scope of services provided by general primary health care (PHC) workers is a 'task shifting' strategy to help increase access to eye care in Africa. PEC training, in theory, teaches PHC workers to recognize specific symptoms and signs and to treat or refer according to these. We tested the sensitivity of these symptoms and signs at identifying significant eye pathology. METHODS Specialized eye care personnel in three African countries evaluated specific symptoms and signs, using a torch alone, in patients who presented to eye clinics. Following this, they conducted a more thorough examination necessary to make a definite diagnosis and manage the patient. The sensitivities and specificities of the symptoms and signs for identifying eyes with conditions requiring referral or threatening sight were calculated. RESULTS Sensitivities of individual symptoms and signs to detect sight threatening pathology ranged from 6.0% to 55.1%; specificities ranged from 8.6 to 98.9. Using a combination of symptoms or signs increased the sensitivity to 80.8 but specificity was 53.2. CONCLUSIONS In this study, the sensitivity and specificity of commonly used symptoms and signs were too low to be useful in guiding PHC workers to accurately identify and refer patients with eye complaints. This raises the question of whether this task shifting strategy is likely to contribute to reducing visual loss or to providing an acceptable quality service.
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Primary eye care skills scores for health workers in routine and enhanced supervision settings. Public Health 2013; 128:96-100. [PMID: 24359760 DOI: 10.1016/j.puhe.2013.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 10/03/2013] [Accepted: 10/11/2013] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Primary health care in Tanzania is provided at two types of health units, the dispensary and the health centre. Theoretically, primary health workers (with knowledge of primary eye care [PEC]) are ideally placed to identify people in need of eye care services. In Tanzania, they are expected to be able to identify, treat, or correctly refer a number of eye conditions including cataract, trauma, presbyopia, and the 'red eye'. They are also expected to be able to measure visual acuity correctly and to educate the community about prevention. OBJECTIVES The objective was to determine the effect of enhanced supervision of health workers on PEC knowledge and skills in Kilimanjaro Region, Tanzania. STUDY DESIGN This was a quasi-experimental, cluster randomized intervention study of an enhanced supervisory method compared to a routine supervisory method; 36 dispensaries were randomly allocated into the two groups. PARTICIPANTS Health workers based at government dispensaries in Mwanga District. DATA COLLECTION Participants were interviewed pre and post intervention and the information was recorded using a standardized pretested questionnaire. RESULTS Mean scores of knowledge in healthcare workers was higher in the intervention group (score = 6.43, 80.4% improvement) compared to the non-intervention group (score = 4.71, 58.9% improvement). The ability to describe and demonstrate vision testing was better (score = 1.8) in the enhanced supervision group compared to the routine supervision group (score = 0.88, P = 0.03). There was a high level of attrition (24%) within one year from the time of baseline survey, especially amongst clinical officers (44%). CONCLUSION During the pilot study, enhanced supervision improved PEC knowledge and skills of health workers compared to health workers with routine supervision. RECOMMENDATIONS Training in PEC needs revision to become more practicum-based. There is need to revise supervision guidelines (to be skills-based) and the supervision skills of district eye coordinators (DECs) need to be enhanced. There is a huge need to improve governance (accountability and rule of law) of health staff.
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Comparing key informants to health workers in identifying children in need of surgical eye care services. Int Health 2013; 4:1-3. [PMID: 24030874 DOI: 10.1016/j.inhe.2011.09.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The objective of the study was to compare the productivity of key informants (KIs) and dedicated health workers (HWs) in identifying children with surgical eye care needs. In two regions of Tanzania, KIs and HWs were trained to identify and register children with severe visual impairment or blindness, with the objective of providing them with surgical eye care services. Identified children were examined at predetermined sites. The total numbers of children in need of surgical services identified by KIs and HWs were compared to measure their relative efficacy. A total of 197 KIs and 63 HWs were trained in the two regions. Five hundred and forty-nine children were identified by KIs and 22 children were identified by HWs: KIs were three times more productive than the HWs. Most of the children identified and examined had serious eye pathology and received surgery or low vision services. The cost per child found was significantly less for children found by KI compared to HW. The study indicates that, in rural Africa, finding children in need of surgical and low vision interventions and ensuring that they are properly screened appears to require community-based efforts.
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Challenges faced by key informants practicing case finding for vision loss in children: the experience in Cross River State, Nigeria. Int Health 2013; 5:259-65. [PMID: 24105974 DOI: 10.1093/inthealth/iht024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND To identify challenges faced by key informants (KIs) in a childhood blindness and severe visual impairment survey in Cross River State (CRS), Nigeria. METHODS Based on eligibility 742 KIs were selected by their village/clan heads in the 18 local government areas (LGAs) of Cross River State. After training in each LGA, KIs were to identify children with visual problems. KIs used a number of methods to identify children with vision loss. After the case detection period, KIs were requested to bring children suspected of vision problems to a central site for examination. Following this, an interviewer-administered semi-structured interview was used to obtain information from the KIs. Thematic content analysis was used to identify these challenges. RESULTS Among the 742 KIs, 642 did not provide any comment on challenges during interview; 100 KIs reported challenges. Major challenge themes identified were issues related to the family of the child and issues related to operational conditions, principally transportation, communication, and incentives. CONCLUSIONS It is likely that challenges were under-reported. Research is needed to understand why some parents feel stigmatized by having children with vision problems. Community based programmes need to strengthen community awareness, address trust issues, and ensure transportation and communication are improved in order to enhance programme success.
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Refractive error blindness in older africans. Ophthalmology 2013; 120:e40. [PMID: 23823512 DOI: 10.1016/j.ophtha.2013.03.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 03/19/2013] [Indexed: 10/26/2022] Open
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Glaucoma after pediatric cataract surgery in a population with limited access to care. J AAPOS 2013; 17:158-62. [PMID: 23528376 DOI: 10.1016/j.jaapos.2012.11.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 11/14/2012] [Accepted: 11/14/2012] [Indexed: 11/25/2022]
Abstract
BACKGROUND Cataract is a leading cause of childhood blindness in eastern Africa and other resource-constrained regions around the world, and high-quality surgical centers are increasingly responding to this challenge. Despite evidence concerning the ongoing risk of postoperative glaucoma after lensectomy, little is known of the incidence of glaucoma after pediatric cataract surgery in Africa. We sought to evaluate the frequency and predictors of postoperative glaucoma in this setting. METHODS The medical records of all children who underwent surgery for congenital or developmental cataract between 2003 and 2005 at the Kilimanjaro Christian Medical Centre were retrospectively reviewed to determine the incidence of postoperative glaucoma. Potential risk factors were evaluated by means of logistic regression. RESULTS Cumulative incidence of glaucoma at 3 years was 6.5% (95% CI, 2.5-16.0), and the annual incidence rate was 2.0 cases per 100 operated eyes (95% confidence interval, 0.74-4.37). Total time of follow-up and absence of primary intraocular lens implantation correlated with risk for postoperative glaucoma, but multivariate analysis could not confirm independent associations. CONCLUSIONS As cataract surgical rates continue to increase and pediatric ophthalmology centers in Africa progress toward the goals of Vision 2020: The Right to Sight, renewed efforts must be directed toward the long-term postoperative care of all children undergoing operation for pediatric cataract.
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Three-year follow up of primary health care workers trained in identification of blind and visual impaired children in Malawi. Health (London) 2013. [DOI: 10.4236/health.2013.511241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Rapid assessment of avoidable blindness in two northern provinces of Burundi without eye services. Ophthalmic Epidemiol 2012; 19:211-5. [PMID: 22775276 DOI: 10.3109/09286586.2012.690493] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To determine the prevalence and causes of blindness, severe visual impairment and visual impairment as well as cataract surgical coverage in two northern provinces of Burundi for the purpose of planning eye services. METHODS The population-based Rapid Assessment of Avoidable Blindness survey methodology was used. RESULTS Of 3800 people enrolled, 3684 (97%) were examined. The sample prevalences of blindness, severe visual impairment, and visual impairment were 1.1% (95% confidence interval, CI 0.8-1.4), 0.6% (95% CI 0.4-0.9), and 1.7% (95% CI 1.3-2.1), respectively. The leading causes of blindness were cataract (55%) and posterior segment causes (37%). Severe visual impairment was mainly due to cataract (43%) and refractive error (39%), and visual impairment was mainly due to refractive error (67%) and cataract (18%). Cataract surgical coverage by person at the level of <6/60 was 15%. CONCLUSIONS The low prevalence of vision loss in this area with no eye services and a low cataract surgical coverage rate is surprising and possibly due to the effects of the previous years of conflict in which those with decreased vision may have been most likely to perish. If this explanation is correct, then Burundi needs to plan to deal with a markedly increasing prevalence of cataract in future.
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Prevalence of raised intracranial pressure in cerebral malaria detected by optic nerve sheath ultrasound. Am J Trop Med Hyg 2012; 87:985-8. [PMID: 23033398 DOI: 10.4269/ajtmh.2012.11-0459] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We aimed to use optic nerve sheath (ONS) ultrasound to determine the prevalence of raised intracranial pressure (ICP) in African children with cerebral malaria (CM); and if increased ONS diameter is associated with poor outcome. We measured ONS diameter in 101 children with CM and 11 children with malaria and impaired consciousness in Malawi. The prevalence of raised ICP detected by increased ONS diameter was 49%. Case fatality was similar in children with increased ONS diameter on admission (9/55) and those children without increased ONS diameter (11/57). Neurological sequelae were more common in those children with increased ONS diameter (7/46 versus 2/46, P < 0.05). Lumbar puncture (LP) opening pressure was elevated in 95% of 46 children who underwent LP. In Malawian children with CM, raised ICP is less commonly detected by ONS ultrasound than LP. This study suggests that raised ICP is not universal in CM and that other mechanisms may account for coma.
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Abstract
OBJECTIVES Non-physician cataract surgeons (NPCS) provide cataract surgical services in some Sub-Saharan African (SSA) countries. However, their training, placement, legal framework and supervision have not been documented. We sought to do so to inform decision-making regarding future training. METHODS Standard questionnaires were sent to national eye coordinators and other ophthalmologic leaders in Africa to collect information. Face-to-face interviews were conducted at training programmes in Ethiopia, Tanzania and Kenya, and email interviews were conducted with directors at training programmes in the Gambia and Malawi. RESULTS Responses were provided for 31/39 (79%) countries to which questionnaires were sent. These countries represent about 90% of the population of SSA. Overall, 17 countries have one or more NPCS; two-thirds of the total 245 NPCS are found in only three countries. Thirty-six percent of NPCS work alone, but a formal functioning supervision system was reported to be present in only one country. The training centres are similar and face similar challenges. CONCLUSIONS There is considerable variation across SSA in the use and acceptance of NPCS. The placement and support of NPCS after training generally does not follow expectations, and training centres have little role in this. Overall, there was no consensus on whether the cadre, as it is currently viewed, is necessary, desirable or will contribute to addressing cataract surgical needs in SSA.
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Uptake of cataract surgery in Sava Region, Madagascar: role of cataract case finders in acceptance of cataract surgery. Int Ophthalmol 2012; 32:107-11. [DOI: 10.1007/s10792-012-9523-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 01/17/2012] [Indexed: 11/25/2022]
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Blindness and visual impairment due to uncorrected refractive error in sub-Saharan Africa: review of recent population-based studies. Br J Ophthalmol 2012; 96:927-30. [PMID: 22317912 DOI: 10.1136/bjophthalmol-2011-300426] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM The authors aimed to review published data on uncorrected refractive error (URE) as a cause of blindness and visual impairment in adults aged ≥40 years in sub-Saharan Africa (SSA). METHODS Data were extracted from population-based prevalence surveys measuring presenting visual acuity (PVA). Results from 11 surveys performed in 10 countries in SSA, encompassing 39,458 people aged ≥40 years and older, are presented. RESULTS The prevalence of blindness (PVA<3/60 in better eye) ranged from 1.1% in an urban district of Cameroon to 7.9% in a rural district in Ethiopia. More than half of studies (6/11) reported no blindness due to URE. The proportion of moderate visual impairment (PVA ≤6/60 and >6/18) due to URE ranged from 12.3% to 57.1%. Excluding two studies that included uncorrected aphakia as part of URE, the highest proportion of blindness and severe visual impairment due to uncorrected aphakia was found in Gambia (15.2%) and Nigeria (15.8%), respectively. CONCLUSION Although URE is a leading cause of visual impairment, it does not represent a major cause of blindness in SSA.
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Abstract
Reducing visual impairment and blindness in children in resource-poor countries is one of the key components of the major global prevention of blindness initiative, VISION 2020 the Right to Sight. Although visual impairment and blindness among children is much less common than among adults, the potential lifespan of a child means that the lifelong impact of such impairment is very large. Over 10 years ago, it was estimated that, globally, 1.4 million children were blind. Much has changed in the past 10-20 years and there is a need to reassess both the magnitude and causes of global childhood blindness and visual impairment. While the widespread implementation of vitamin A supplementation and measles immunisation programmes have led to a reduction in vitamin A deficiency-related blindness in many poor countries, retinopathy of prematurity is now undergoing a third wave of endemicity, particularly in newly industrialising countries in Latin America and Asia. Childhood cataract is better recognised as an important potentially avoidable problem, as is paediatric glaucoma and refractive error in some populations. Trained paediatric ophthalmologists, although still too few, are growing in number in poor countries. A programmatic approach with a multidisciplinary team is essential to reducing childhood blindness. The elements of such programmes and the need for planning are discussed.
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Clinical factors associated with malignancy and HIV status in patients with ocular surface squamous neoplasia at Kilimanjaro Christian Medical Centre, Tanzania. Br J Ophthalmol 2011; 96:482-4. [PMID: 22075543 DOI: 10.1136/bjophthalmol-2011-300485] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS To describe the clinical characteristics of ocular surface squamous neoplasia (OSSN) in a sub-Saharan referral hospital setting according to histopathological diagnosis and HIV status. METHODS All patients were enrolled who presented consecutively to the Kilimanjaro Christian Medical College eye department with lesions suspected to be OSSN from September 2005 to May 2007 and from February 2008 to September 2008. Clinical characteristics were documented on a standardised form, excision biopsies were performed and histopathological diagnosis was obtained on all cases. Data were analysed to look for associations among various factors. RESULTS 150 patients were enrolled. Histopathological study showed OSSN in 88% of cases. Of these, 128 (85.6%) were under the age of 50 years and 60% were HIV positive. The median CD4 cell count was 71 cells/μl among HIV-positive cases. Independent of size, the lesions of patients who were HIV positive were more likely to be higher grade malignancy than those who were HIV negative. CONCLUSION In a sub-Saharan setting, OSSN occurs in persons who are younger than in industrialised countries and is often associated with HIV positivity. CD4 cell counts indicate that a majority of HIV-positive patients with OSSN are significantly immunosuppressed at presentation. Higher grade malignancy in this group could indicate a more aggressive course.
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CMV retinitis screening and treatment in a resource-poor setting: three-year experience from a primary care HIV/AIDS programme in Myanmar. J Int AIDS Soc 2011; 14:41. [PMID: 21843351 PMCID: PMC3163508 DOI: 10.1186/1758-2652-14-41] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Accepted: 08/15/2011] [Indexed: 11/10/2022] Open
Abstract
Background Cytomegalovirus retinitis is a neglected disease in resource-poor settings, in part because of the perceived complexity of care and because ophthalmologists are rarely accessible. In this paper, we describe a pilot programme of CMV retinitis management by non-ophthalmologists. The programme consists of systematic screening of all high-risk patients (CD4 <100 cells/mm3) by AIDS clinicians using indirect ophthalmoscopy, and treatment of all patients with active retinitis by intravitreal injection of ganciclovir. Prior to this programme, CMV retinitis was not routinely examined for, or treated, in Myanmar. Methods This is a retrospective descriptive study. Between November 2006 and July 2009, 17 primary care AIDS clinicians were trained in indirect ophthalmoscopy and diagnosis of CMV retinitis; eight were also trained in intravitreal injection. Evaluation of training by a variety of methods documented high clinical competence. Systematic screening of all high-risk patients (CD4 <100 cells/mm3) was carried out at five separate AIDS clinics throughout Myanmar. Results A total of 891 new patients (1782 eyes) were screened in the primary area (Yangon); the majority of patients were male (64.3%), median age was 32 years, and median CD4 cell count was 38 cells/mm3. CMV retinitis was diagnosed in 24% (211/891) of these patients. Bilateral disease was present in 36% of patients. Patients with active retinitis were treated with weekly intravitreal injection of ganciclovir, with patients typically receiving five to seven injections per eye. A total of 1296 injections were administered. Conclusions A strategy of management of CMV retinitis at the primary care level is feasible in resource-poor settings. With appropriate training and support, CMV retinitis can be diagnosed and treated by AIDS clinicians (non-ophthalmologists), just like other major opportunistic infections.
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Abstract
Accurate diagnosis of cerebral malaria (CM) is important for patient management, epidemiological and end point surveillance, and enrolling patients with CM in studies of pathogenesis or therapeutic trials. In malaria-endemic areas, where asymptomatic Plasmodium falciparum parasitemia is common, a positive blood film in a comatose individual does not prove that the coma is due to malaria. A retinopathy consisting of two unique features - patchy retinal whitening and focal changes of vessel color - is highly specific for encephalopathy of malarial etiology. White-centered retinal hemorrhages are a common but less specific feature. Either indirect or direct ophthalmoscopy can be used to identify the changes, and both procedures can be learned and practiced by nonspecialist clinicians. In view of its important contributions to both clinical care and research, examination of the retina should become a routine component of the assessment of a comatose child or adult when CM is a possible diagnosis.
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Overcoming gender inequity in prevention of blindness and visual impairment in Africa. Middle East Afr J Ophthalmol 2011; 18:98-101. [PMID: 21731318 PMCID: PMC3119299 DOI: 10.4103/0974-9233.80695] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Background: Globally, and in Africa, after adjusting for age, women are about 1.4 times more likely to be blind than men. While women generally live longer than men, the lack of accessibility to and use of services is likely the most important reason for excess blindness in women in Africa. Aim: We sought to review the literature on vision loss in Africa and summarize the findings related to gender equity. Materials and Methods: Information from across sub-Saharan Africa was collected on the evidence of gender inequity and reasons for this inequity. Finally, the results were used to generate suggestions on how gender equity could be improved. Results: In all published surveys (except one), cataract surgical coverage among women was lower than cataract surgical coverage among men. Although data available are limited, similar findings appeared in the use of services for other disease conditions, notably, childhood cataract and glaucoma. Evidence suggests that a variety of approaches are needed to improve the use of eye care services. Three main strategies are needed to address gender inequity in vision loss in Africa. First, it is important to address transport needs. Second, counseling of patients and family members is required. Finally, programs need to put in place pricing systems that make the services affordable the population. Conclusions: VISION 2020 can be achieved in Africa, but investment is needed in a variety of strategies that will ensure that eye care services are affordable, accessible, and acceptable to women and girls.
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