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Lewallen S, Schmidt E, Jolley E, Lindfield R, Dean WH, Cook C, Mathenge W, Courtright P. 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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Binagwaho A, Scott K, Rosewall T, Mackenzie G, Rehnborg G, Hannema S, Presente M, Noe P, Mathenge W, Nkurikiye J, Habiyaremye F, Dushime T. Improving eye care in Rwanda. Bull World Health Organ 2015; 93:429-34. [PMID: 26240465 PMCID: PMC4450705 DOI: 10.2471/blt.14.143149] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 02/16/2015] [Accepted: 02/16/2015] [Indexed: 11/27/2022] Open
Abstract
PROBLEM Visual impairment affects nearly 285 million people worldwide. Although there has been much progress in combating the burden of visual impairment through initiatives such as VISION 2020, barriers to progress, especially in African countries, remain high. APPROACH The Rwandan Ministry of Health has formed partnerships with several nongovernmental organizations and has worked to integrate their efforts to prevent and treat visual impairment, including presbyopia. LOCAL SETTING Rwanda, an eastern African country of approximately 11 million people. RELEVANT CHANGES The Rwandan Ministry of Health developed a single national plan that allows key partners in vision care to coordinate more effectively in measuring eye disease, developing eye care infrastructure, building capacity, controlling disease, and delivering and evaluating services. LESSONS LEARNT Collaboration between stakeholders under a single national plan has ensured that resources and efforts are complementary, optimizing the ability to provide eye care. Improved access to primary eye care and insurance coverage has increased demand for services at secondary and tertiary levels. A comprehensive strategy that includes prevention as well as a supply chain for glasses and lenses is needed.
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Bastawrous A, Mathenge W, Peto T, Weiss HA, Rono H, Foster A, Burton M, Kuper H. The Nakuru eye disease cohort study: methodology & rationale. BMC Ophthalmol 2014; 14:60. [PMID: 24886366 PMCID: PMC4024270 DOI: 10.1186/1471-2415-14-60] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 04/03/2014] [Indexed: 11/22/2022] Open
Abstract
Background No longitudinal data from population-based studies of eye disease in sub-Saharan-Africa are available. A population-based survey was undertaken in 2007/08 to estimate the prevalence and determinants of blindness and low vision in Nakuru district, Kenya. This survey formed the baseline to a six-year prospective cohort study to estimate the incidence and progression of eye disease in this population. Methods/Design A nationally representative sample of persons aged 50 years and above were selected between January 2007 and November 2008 through probability proportionate to size sampling of clusters, with sampling of individuals within clusters through compact segment sampling. Selected participants underwent detailed ophthalmic examinations which included: visual acuity, autorefraction, visual fields, slit lamp assessment of the anterior and posterior segments, lens grading and fundus photography. In addition, anthropometric measures were taken and risk factors were assessed through structured interviews. Six years later (2013/2014) all subjects were invited for follow-up assessment, repeating the baseline examination methodology. Discussion The methodology will provide estimates of the progression of eye diseases and incidence of blindness, visual impairment, and eye diseases in an adult Kenyan population.
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Mathenge W, Bastawrous A, Peto T, Leung I, Yorston D, Foster A, Kuper H. Prevalence and correlates of diabetic retinopathy in a population-based survey of older people in Nakuru, Kenya. Ophthalmic Epidemiol 2014; 21:169-77. [PMID: 24758280 DOI: 10.3109/09286586.2014.903982] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To estimate the prevalence of and factors associated with diabetic retinopathy (DR) among people aged ≥ 50 years in Nakuru, Kenya. METHODS Probability-proportional-to-size sampling was used to select 100 clusters of 50 people aged ≥ 50 years during 2007-2008. Households within clusters were selected through compact segment sampling. Participants underwent dilated slit lamp biomicroscopy (SLB) by an ophthalmologist and digital retinal photography. Images were graded for DR at the Moorfields Eye Hospital Reading Centre, UK. Diagnosis of DR was based on retinal images where available, otherwise on SLB. Anthropometric measures, including random glucose, and lifestyle factors were measured. RESULTS We examined 4414 adults (response rate 88.1%), of whom 287 had diabetes. A total of 277 of these were screened for DR by SLB, and 195 also underwent retinal photography. The prevalence of any DR diagnosed by retinal images among diabetics was 35.9% (95% confidence interval, CI, 29.7-42.6%). The most common grade of DR was mild/moderate non-proliferative DR (NPDR; 22.1%, 95% CI 16.1-29.4%), while severe NPDR and proliferative DR were less frequent (13.9%, 95% CI 10.0-18.8%). SLB significantly underdiagnosed DR compared to retinal photography, particularly for milder grades. Of 87 individuals with DR, 23 had visual impairment (visual acuity <6/12). DR was associated with younger age, male sex, duration and control of diabetes, and treatment compliance. Coverage of photocoagulation in those needing immediate laser was low (25%). CONCLUSION DR remains a threat to sight in people with diabetes in this elderly Kenyan population. Screening diabetics may enable those requiring treatment to be identified in time to preserve their sight.
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Lewallen S, Courtright P, Etya'ale D, Mathenge W, Schmidt E, Oye J, Clark A, Williams T. 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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Mathenge W. Age-related macular degeneration. COMMUNITY EYE HEALTH 2014; 27:49-50. [PMID: 25918464 PMCID: PMC4322741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Andriamanjato HH, Mathenge W, Kalua K, Courtright P, Lewallen S. 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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Sherwin JC, Mathenge W, Hassan K, Cook C, Kalua K, Courtright P, Lewallen S. 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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du Toit R, Faal HB, Etya'ale D, Wiafe B, Mason I, Graham R, Bush S, Mathenge W, Courtright P. Evidence for integrating eye health into primary health care in Africa: a health systems strengthening approach. BMC Health Serv Res 2013; 13:102. [PMID: 23506686 PMCID: PMC3616885 DOI: 10.1186/1472-6963-13-102] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 03/02/2013] [Indexed: 12/03/2022] Open
Abstract
Background The impact of unmet eye care needs in sub-Saharan Africa is compounded by barriers to accessing eye care, limited engagement with communities, a shortage of appropriately skilled health personnel, and inadequate support from health systems. The renewed focus on primary health care has led to support for greater integration of eye health into national health systems. The aim of this paper is to demonstrate available evidence of integration of eye health into primary health care in sub-Saharan Africa from a health systems strengthening perspective. Methods A scoping review method was used to gather and assess information from published literature, reviews, WHO policy documents and examples of eye and health care interventions in sub-Saharan Africa. Findings were compiled using a health systems strengthening framework. Results Limited information is available about eye health from a health systems strengthening approach. Particular components of the health systems framework lacking evidence are service delivery, equipment and supplies, financing, leadership and governance. There is some information to support interventions to strengthen human resources at all levels, partnerships and community participation; but little evidence showing their successful application to improve quality of care and access to comprehensive eye health services at the primary health level, and referral to other levels for specialist eye care. Conclusion Evidence of integration of eye health into primary health care is currently weak, particularly when applying a health systems framework. A realignment of eye health in the primary health care agenda will require context specific planning and a holistic approach, with careful attention to each of the health system components and to the public health system as a whole. Documentation and evaluation of existing projects are required, as are pilot projects of systematic approaches to interventions and application of best practices. Multi-national research may provide guidance about how to scale up eye health interventions that are integrated into primary health systems.
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Syed A, Polack S, Eusebio C, Mathenge W, Wadud Z, Mamunur AKM, Foster A, Kuper H. Predictors of attendance and barriers to cataract surgery in Kenya, Bangladesh and the Philippines. Disabil Rehabil 2013; 35:1660-7. [DOI: 10.3109/09638288.2012.748843] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Mathenge W, Bastawrous A, Peto T, Leung I, Foster A, Kuper H. Prevalence of age-related macular degeneration in Nakuru, Kenya: a cross-sectional population-based study. PLoS Med 2013; 10:e1001393. [PMID: 23431274 PMCID: PMC3576379 DOI: 10.1371/journal.pmed.1001393] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 01/09/2013] [Indexed: 10/31/2022] Open
Abstract
BACKGROUND Diseases of the posterior segment of the eye, including age-related macular degeneration (AMD), have recently been recognised as the leading or second leading cause of blindness in several African countries. However, prevalence of AMD alone has not been assessed. We hypothesized that AMD is an important cause of visual impairment among elderly people in Nakuru, Kenya, and therefore sought to assess the prevalence and predictors of AMD in a diverse adult Kenyan population. METHODS AND FINDINGS In a population-based cross-sectional survey in the Nakuru District of Kenya, 100 clusters of 50 people 50 y of age or older were selected by probability-proportional-to-size sampling between 26 January 2007 and 11 November 2008. Households within clusters were selected through compact segment sampling. All participants underwent a standardised interview and comprehensive eye examination, including dilated slit lamp examination by an ophthalmologist and digital retinal photography. Images were graded for the presence and severity of AMD lesions following a modified version of the International Classification and Grading System for Age-Related Maculopathy. Comparison was made between slit lamp biomicroscopy (SLB) and photographic grading. Of 4,381 participants, fundus photographs were gradable for 3,304 persons (75.4%), and SLB was completed for 4,312 (98%). Early and late AMD prevalence were 11.2% and 1.2%, respectively, among participants graded on images. Prevalence of AMD by SLB was 6.7% and 0.7% for early and late AMD, respectively. SLB underdiagnosed AMD relative to photographic grading by a factor of 1.7. After controlling for age, women had a higher prevalence of early AMD than men (odds ratio 1.5; 95% CI, 1.2-1.9). Overall prevalence rose significantly with each decade of age. We estimate that, in Kenya, 283,900 to 362,800 people 50 y and older have early AMD and 25,200 to 50,500 have late AMD, based on population estimates in 2007. CONCLUSIONS AMD is an important cause of visual impairment and blindness in Kenya. Greater availability of low vision services and ophthalmologist training in diagnosis and treatment of AMD would be appropriate next steps. Please see later in the article for the Editors' Summary.
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Kandeke L, Mathenge W, Giramahoro C, Undendere FPA, Ruhagaze P, Habiyakare C, Courtright P, Lewallen S. 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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Ploubidis GB, Mathenge W, De Stavola B, Grundy E, Foster A, Kuper H. Socioeconomic position and later life prevalence of hypertension, diabetes and visual impairment in Nakuru, Kenya. Int J Public Health 2012; 58:133-41. [PMID: 22814479 DOI: 10.1007/s00038-012-0389-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 05/15/2012] [Accepted: 06/21/2012] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVES We examined the extent to which the association between socioeconomic position (SEP) and later life prevalence of hypertension, diabetes and visual impairment in Nakuru, Kenya is mediated by health-related behaviour. METHODS We used data from a community survey of 4,314 participants sampled from urban and rural areas in Nakuru, Kenya. Structural equation modelling was employed to estimate the direct and indirect--via health-related behaviour--effects of SEP on the three health outcomes. RESULTS The accumulation of material resources was positively associated with hypertension and diabetes, whereas both education and material resources had a negative association with the prevalence of visual impairment. However, the observed health inequalities were not due to variation between SEP groups in health-related behaviour. CONCLUSIONS The pattern of associations between education, material resources and the three health outcomes varied, suggesting that in Kenya, unlike the observed pattern of inequalities in high income countries, different dimensions of SEP provide different aspects of protection as well as risk. Smoking and alcohol use did not appear to mediate the observed associations, in contrast with countries past the epidemiologic transition.
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Mathenge W, Bastawrous A, Foster A, Kuper H. The Nakuru posterior segment eye disease study: methods and prevalence of blindness and visual impairment in Nakuru, Kenya. Ophthalmology 2012; 119:2033-9. [PMID: 22721919 DOI: 10.1016/j.ophtha.2012.04.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 04/02/2012] [Accepted: 04/17/2012] [Indexed: 10/28/2022] Open
Abstract
OBJECTIVES To estimate the prevalence of blindness and visual impairment (VI) in adults aged ≥50 years in the Nakuru district of Kenya and to identify sociodemographic risk factors for these conditions. We also sought to validate the Rapid Assessment of Avoidable Blindness (RAAB) methodology. PARTICIPANTS There were 5010 subjects enumerated for this study. Of these, 4414 participants underwent examination, for a response rate of 88.1%. DESIGN Cross-sectional, population-based survey. METHODS Cluster random samplings with probability proportionate to size procedures were used to select a representative cross-sectional sample of adults aged ≥50 years. Each participant was interviewed, had distance visual acuity (VA) measured with reduced logarithm of the minimal angle of resolution tumbling-E chart, underwent autorefraction, and thereby had measurements of presenting, uncorrected, and best-corrected VA. All participants, regardless of vision, underwent detailed ophthalmic examinations including slit-lamp assessment and dilated retinal photographs. MAIN OUTCOME MEASURES Visual acuity of <6/12. RESULTS A representative sample of 4414 adults were enumerated (response rate, 88.1%). The prevalence of blindness (VA < 3/60 in better eye) was 1.6% (95% confidence interval [CI], 1.2-2.1%) and of VI, 0.4% (95% CI, 0.3-0.7%); 8.1% (95% CI, 7.2-9.2%); and 5.1% (95% CI, 4.3-6.1%) were severely (<6/60-3/60), moderately (<6/18-6/60), or mildly (<6/12-6/18) visually impaired, respectively. Being male, having less education, having Kalenjin tribal origin, and being ≥80 years old were associated with increased blindness prevalence. Prevalence estimates were comparable to a RAAB performed in the same area 2 years earlier. CONCLUSIONS This survey provides reliable estimates of blindness and VI prevalence in Nakuru. Older age and tribal origin were identified as predictors of these conditions. This survey validates the use of RAAB as a method of estimating blindness and VI prevalence.
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Sallo FB, Leung I, Mathenge W, Kyari F, Kuper H, Gilbert CE, Bird AC, Peto T. The prevalence of type 2 idiopathic macular telangiectasia in two African populations. Ophthalmic Epidemiol 2012; 19:185-9. [PMID: 22364548 DOI: 10.3109/09286586.2011.638744] [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 Type 2 idiopathic macular telangiectasia (MacTel) is a progressive retinal disease associated with a slow deterioration of visual acuity, starting in the fifth to seventh decades of life. The etiology and pathogenesis of the disease are little known, and no effective therapy is available. We aimed to estimate the prevalence and describe the phenotype of type 2 MacTel in two African populations. METHODS From two population-based cross-sectional surveys conducted nationally in Nigeria and in the Nakuru district of Kenya, patients with fundus features of type 2 MacTel were selected. Diagnosis was based on color fundus images, grading performed according to the MacTel Study protocol and staged using the Gass and Blodi system. Disease phenotype and clinical characteristics of affected participants were assessed. RESULTS Of 8599 total participants, five showed a phenotype compatible with type 2 MacTel. Prevalence was estimated as 0.06% (95% confidence interval [CI] 0.02-0.21%) in Kenya, 0.06% (95% CI 0.01-0.17%) in Nigeria, and overall at 0.06% (95% CI 0.02-0.14%). Mean age was 62 years (SD 5 years), four of five affected participants were female, and none had a history of diabetes. Median corrected visual acuity was 6/12 in the better eye and 6/69 in the worse eye. CONCLUSIONS The estimated prevalence and phenotype of type 2 MacTel in the African populations examined were similar to those in predominantly white populations. All data published so far are based on the analysis of color fundus images only and are thus likely to underestimate the true prevalence of this disease.
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Müller A, Zerom M, Limburg H, Ghebrat Y, Meresie G, Fessahazion K, Beyene K, Mathenge W, Mebrahtu G. Results of a rapid assessment of avoidable blindness (RAAB) in Eritrea. Ophthalmic Epidemiol 2011; 18:103-8. [PMID: 21609238 DOI: 10.3109/09286586.2010.545932] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To collect baseline data for planning of the National Blindness Prevention & Control Program and for monitoring future achievements. METHODS Sixty six clusters of 50 people were selected from a sampling frame that included all 2,593 villages in Eritrea (population 3.56 million). Within each selected village, 50 eligible people aged 50+ years were selected. All eligible participants underwent visual acuity (VA) measurement followed by examination by an ophthalmologist if the presenting VA (PVA) was less than 6/18. RESULTS Three thousand one hundred sixty three of the 3300 eligible persons were examined (coverage 95.9%). The adjusted prevalence of blindness (PVA < 3/60 in the better eye) in the survey population was 7.5% (95% confidence interval [CI]: 6.2-8.8%), bilateral severe visual impairment (PVA < 6/60 to ≥ 3/60 in the better eye) 3.0% (95% CI: 2.3-3.7%) and of bilateral moderate visual impairment (PVA < 6/18 to ≥ 6/60 in the better eye) 10.5% (95% CI: 9.1-11.9%). Of all bilateral blindness 55% was due to cataract. The adjusted cataract surgical coverage (percentage of people requiring cataract surgery that have had surgery) was 68% for blind people and 41% for blind eyes. Cataract surgery outcome was poor (PVA < 6/60) in 39% of all eyes operated in the past. CONCLUSIONS The prevalence of blindness was high compared to recent surveys in Africa. Visual outcome after cataract surgery potentially could be improved by more detailed pre-operative examination, coaching of surgeons, and provision of adequate optical correction, including routine monitoring of visual outcome after cataract surgery. The development of intervention programs for refractive error and glaucoma should be considered.
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Lewallen S, Williams TD, Dray A, Stock BC, Mathenge W, Oye J, Nkurikiye J, Kimani K, Müller A, Courtright P. Estimating incidence of vision-reducing cataract in Africa: a new model with implications for program targets. ACTA ACUST UNITED AC 2011; 128:1584-9. [PMID: 21149783 DOI: 10.1001/archophthalmol.2010.307] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To estimate the incidence of vision-reducing cataract in sub-Saharan Africa and use these data to calculate cataract surgical rates (CSR) needed to eliminate blindness and visual impairment due to cataract. METHODS Using data from recent population-based, standardized, rapid-assessment surveys, we calculated the age-specific prevalence of cataract (including operated and unoperated eyes) from surveys in 7 "districts" across Africa. This was done at 3 levels of visual acuity. Then we used the age-specific prevalence data to develop a model to estimate age-specific incidence at different visual acuities, taking into account differences in mortality rates between those with cataract compared with those without. The model included development of opacity in the first eye and second eye of people older than 50 years. The incidence data were used to calculate target cataract surgical rates. RESULTS Incidence and CSR needs varied significantly in different sites and were lower in some than expected. Cataract surgical rates may depend on genetic, environmental, or cultural variations and will vary with population structure, which is not uniform across Africa. CONCLUSION Africa should not be viewed as homogeneous in terms of cataract incidence or CSR needed. These CSR calculations should be useful for more appropriate planning of human resources and service delivery on the continent. The methodology can be applied to other population-based data as they become available to determine appropriate CSR targets.
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Courtright P, Seneadza A, Mathenge W, Eliah E, Lewallen S. Primary eye care in sub-Saharan African: do we have the evidence needed to scale up training and service delivery? ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2010; 104:361-7. [PMID: 20819303 DOI: 10.1179/136485910x12743554760225] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The models for addressing the delivery of an eye-care service in sub-Saharan Africa have seen considerable revision in the last 30 years, and the on-going challenges, as well as the future needs, will probably require many more changes and new systems. There is a need to assess the different models that are currently employed, in order to ensure that all potential contributions to the elimination of avoidable blindness are used; the evolving concept of primary eye care (PEC) requires such assessment. For the current review, the published literature on eye care provided by general front-line healthworkers was screened for articles that provided evidence of the impact of such PEC on the general delivery of eye care in sub-Saharan Africa. Of the 103 relevant articles detected, only three provided evidence of the effectiveness of PEC and the authors of all three of these articles suggested that such eye care was not meeting the needs or expectations of the target populations, the trainers, or programmes of eye care. Among the main problems identified were a lack of a clear definition of the scope of practice for PEC, the need for clarifying the specific skills that a front-line healthworker could perform correctly, and the changing needs and expectations for the delivery of an eye-care service in Africa. If PEC is to become adequately grounded in Africa, the generation of further evidence of the effectiveness and limitations of such care would be a prudent move.
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Polack S, Eusebio C, Mathenge W, Wadud Z, Mamunur A, Fletcher A, Foster A, Kuper H. The Impact of Cataract Surgery on Health Related Quality of Life in Kenya, the Philippines, and Bangladesh. Ophthalmic Epidemiol 2010; 17:387-99. [DOI: 10.3109/09286586.2010.528136] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Kuper H, Polack S, Mathenge W, Eusebio C, Wadud Z, Rashid M, Foster A. Does cataract surgery alleviate poverty? Evidence from a multi-centre intervention study conducted in Kenya, the Philippines and Bangladesh. PLoS One 2010; 5:e15431. [PMID: 21085697 PMCID: PMC2976760 DOI: 10.1371/journal.pone.0015431] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 09/21/2010] [Indexed: 12/03/2022] Open
Abstract
Background Poverty and blindness are believed to be intimately linked, but empirical data supporting this purported relationship are sparse. The objective of this study is to assess whether there is a reduction in poverty after cataract surgery among visually impaired cases. Methodology/Principal Findings A multi-centre intervention study was conducted in three countries (Kenya, Philippines, Bangladesh). Poverty data (household per capita expenditure – PCE, asset ownership and self-rated wealth) were collected from cases aged ≥50 years who were visually impaired due to cataract (visual acuity<6/24 in the better eye) and age-sex matched controls with normal vision. Cases were offered free/subsidised cataract surgery. Approximately one year later participants were re-interviewed about poverty. 466 cases and 436 controls were examined at both baseline and follow-up (Follow up rate: 78% for cases, 81% for controls), of which 263 cases had undergone cataract surgery (“operated cases”). At baseline, operated cases were poorer compared to controls in terms of PCE (Kenya: $22 versus £35 p = 0.02, Bangladesh: $16 vs $24 p = 0.004, Philippines: $24 vs 32 p = 0.0007), assets and self-rated wealth. By follow-up PCE had increased significantly among operated cases in each of the three settings to the level of controls (Kenya: $30 versus £36 p = 0.49, Bangladesh: $23 vs $23 p = 0.20, Philippines: $45 vs $36 p = 0.68). There were smaller increases in self-rated wealth and no changes in assets. Changes in PCE were apparent in different socio-demographic and ocular groups. The largest PCE increases were apparent among the cases that were poorest at baseline. Conclusions/Significance This study showed that cataract surgery can contribute to poverty alleviation, particularly among the most vulnerable members of society. This study highlights the need for increased provision of cataract surgery to poor people and shows that a focus on blindness may help to alleviate poverty and achieve the Millennium Development Goals.
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Mathenge W, Foster A, Kuper H. Urbanization, ethnicity and cardiovascular risk in a population in transition in Nakuru, Kenya: a population-based survey. BMC Public Health 2010; 10:569. [PMID: 20860807 PMCID: PMC2956724 DOI: 10.1186/1471-2458-10-569] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 09/22/2010] [Indexed: 11/25/2022] Open
Abstract
Background Cardiovascular disease (CVD) is the leading cause of death among older people in Africa. This study aimed to investigate the relationship of urbanization and ethnicity with CVD risk markers in Kenya. Methods A cross-sectional population-based survey was carried out in Nakuru Kenya in 2007-2008. 100 clusters of 50 people aged ≥50 years were selected by probability proportionate to size sampling. Households within clusters were selected through compact segment sampling. Participants were interviewed by nurses to collect socio-demographic and lifestyle information. Nurses measured blood pressure, height, weight and waist and hip circumference. A random finger-prick blood sample was taken to measure glucose and cholesterol levels. Hypertension was defined as systolic blood pressure (SBP) ≥140 mm Hg, or diastolic blood pressure (DBP) ≥90 mm Hg or current use of antihypertensive medication; Diabetes as reported current medication or diet control for diabetes or random blood glucose level ≥11.1 mmol/L; High cholesterol as random blood cholesterol level ≥5.2 mmol/L; and Obesity as Body Mass Index (BMI)≥30 kg/m2. Results 5010 eligible subjects were selected, of whom 4396 (88%) were examined. There was a high prevalence of hypertension (50.1%, 47.5-52.6%), obesity (13.0%, 11.7-14.5%), diabetes (6.6%, 5.6-7.7%) and high cholesterol (21.1%, 18.6-23.9). Hypertension, diabetes and obesity were more common in urban compared to rural groups and the elevated prevalence generally persisted after adjustment for socio-demographic, lifestyle, obesity and cardiovascular risk markers. There was also a higher prevalence of hypertension, obesity, diabetes and high cholesterol among Kikuyus compared to Kalenjins, even after multivariate adjustment. CVD risk markers were clustered both across the district and within individuals. Few people received treatment for hypertension (15%), while the majority of cases with diabetes received treatment (68%). Conclusions CVD risk markers are common in Kenya, particularly in urban areas. Exploring differences in CVD risk markers between ethnic groups may help to elucidate the epidemiology of these conditions.
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Mason I, Mathenge W. Equipment for eye care. COMMUNITY EYE HEALTH 2010; 23:21-2. [PMID: 21119915 PMCID: PMC2975112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Polack S, Eusebio C, Mathenge W, Wadud Z, Rashid M, Foster A, Kuper H. The impact of cataract surgery on activities and time-use: results from a longitudinal study in Kenya, Bangladesh and the Philippines. PLoS One 2010; 5:e10913. [PMID: 20531957 PMCID: PMC2879361 DOI: 10.1371/journal.pone.0010913] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Accepted: 05/02/2010] [Indexed: 11/17/2022] Open
Abstract
Background Cataract is the leading cause of blindness in the world, and blindness from cataract is particularly common in low-income countries. The aim of this study is to explore the impact of cataract surgery on daily activities and time-use in Kenya, Bangladesh and the Philippines. Methods/Principal Findings A multi-centre intervention study was conducted in three countries. Time-use data were collected through interview from cases aged ≥50 years with visually impairing cataract (VA <6/24) and age- and gender-matched controls with normal vision (VA≥6/18). Cases were offered free/subsidized cataract surgery. Approximately one year later participants were re-interviewed about time-use. At baseline across the three countries there were 651 cases and 571 controls. Fifty-five percent of cases accepted surgery. Response rate at follow up was 84% (303 out of 361) for operated cases, and 80% (459 out of 571) for controls. At baseline, cases were less likely to carry out and spent less time on productive activities (paid and non-paid work) and spent more time in “inactivity” compared to controls. Approximately one year after cataract surgery, operated cases were more likely to undertake productive activities compared to baseline (Kenya from 55% to 88%; Bangladesh 60% to 95% and Philippines 81% to 94%, p<0.001) and mean time spent on productive activities increased by one-two hours in each setting (p<0.001). Time spent in “inactivity” in Kenya and Bangladesh decreased by approximately two hours (p<0.001). Frequency of reported assistance with activities was more than halved in each setting (p<0.001). Conclusions/Significance The empirical evidence provided by this study of increased time spent on productive activities, reduced time in inactivity and reduced assistance following cataract surgery among older adults in low-income settings has positive implications for well-being and inclusion, and supports arguments of economic benefit at the household level from cataract surgery.
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Courtright P, Murenzi J, Mathenge W, Munana J, Müller A. Reaching rural Africans with eye care services: findings from primary eye care approaches in Rubavu District, Rwanda. Trop Med Int Health 2010; 15:692-6. [PMID: 20374559 DOI: 10.1111/j.1365-3156.2010.02530.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE Assessment of a primary eye care programme in rural Rwanda over 2 years, with the aim of providing evidence to guide the development, training, supervision, or monitoring of primary eye care in Africa. METHOD A comprehensive eye care programme in Rubavu District including a surgical service, health promotion, diagnostic and treatment services, training of health centre nurses and village health workers, and periodic visits by eye professionals to the health centres was implemented. Monitoring systems put in place from the beginning of the programme facilitated assessment of service use over 2 years. RESULTS A total of 6495 people received eye care services at eight health centres (3912 from nurses and 2583 from visiting eye professionals) and 149 Rubavu residents had surgery for cataract. Increases in service use in the first few months were not maintained over the 2-year period. The number of patients receiving surgery for cataract was less than half of the number referred for surgery. CONCLUSION In this setting, initial increases in use of services at health centres were not maintained. Reasons varied and included the observation that VHW tend to refer patients to health centres only when there was a visiting eye professional. Reductions in visits to health centres could also be traced to changing government policies on medicines provided through insurance coverage. Increasing rates of referral and uptake of cataract surgery will require revising programme activities and adopting additional strategies.
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Müller A, Murenzi J, Mathenge W, Munana J, Courtright P. Primary eye care in Rwanda: gender of service providers and other factors associated with effective service delivery. Trop Med Int Health 2010; 15:529-33. [PMID: 20345558 DOI: 10.1111/j.1365-3156.2010.02498.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To assess factors associated with high output of recently trained medical personnel in Rwanda. METHODS Nurses and village health workers (VHW) from all health centres in Rubavu district were included. Data were collected during focus group discussions and through one-to-one interviews. Follow-up interviews were carried out in January 2009. RESULTS There was a wide range from none to all VHW referring people to a health centre. VHW brought more people to the health centre if there was a visiting ophthalmic clinical officer from the Eye Unit offering free screening. VHW output varied; male VHW brought 66.7% of patients identified (regardless of the sex of the health centre nurse), while female VHW brought 5.2 times as many people if the health centre nurse was male compared to if the nurse was female. CONCLUSION Changes in training curriculum and support and supervision of health workers trained in primary eye care (PEC) are likely to lead to improved outputs. Information efforts should reinforce that male and female nurses have the same training and skills in PEC.
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