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Hannah Kuper - One of the best experts on this subject based on the ideXlab platform.
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Rapid Assessment of avoidable blindness and diabetic retinopathy in Taif, Saudi Arabia
2016Co-Authors: Hannah Kuper, Sarah PolackAbstract:Background/aims To estimate the prevalence of blindness, diabetes and diabetic retinopathy (DR) in Taif, Saudi Arabia using the Rapid Assessment of Avoidable Blindness (RAAB) framework. Methods 66 clusters of 50 people aged $50 years were randomly selected. Participants underwent visual acuity measurement and examination by an ophthalmologist. DR among diabetic participants (previous diagnosis and/or random blood glucose>200 mg/dl) was assessed through dilated fundus examination by an ophthalmologist using a direct and indirect ophthalmoscope (‘clinical examination’) and dilated digital fundus photographs graded by a retinal specialist following the Scottish DR grading system (‘reference standard’). Results 3052 (93%) out of 3300 eligible people were examined. The prevalence of blindness was 2.6 % (95% CI 2.0 % to 3.2%). Posterior segment diseases (44%) and cataract (41%) were the leading causes of blindness. The estimated prevalence of diabetes was 29.7 % (28.1% to 31.4%), among whom the prevalence of DR was 36.8 % (33.3 % to 40.2%) and sight-threatening DR (STDR) was 17.5 % (CI 15.1 % to 20.0%). Agreement was good (k>0.6) between the clinical examination and reference standard for any DR and STDR. Conclusions There was a high prevalence of diabetes, DR and STDR. It was possible to assess diabetes and DR within RAAB but it increased the survey duration, cost and complexity
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Rapid Assessment of avoidable blindness and diabetic retinopathy in chiapas mexico
Ophthalmology, 2012Co-Authors: Sarah Polack, David Yorston, Antonio Lopezramos, Sergio Lepeorta, Rogerio Martins Baia, Luciano Alves, Carlos Graualvidrez, Pedro Gomezbastar, Hannah KuperAbstract:Objective To estimate the prevalence and causes of blindness in Chiapas, Mexico, and to assess the feasibility of using the Rapid Assessment of Avoidable Blindness framework to estimate diabetic retinopathy (DR) prevalence. Design A cross-sectional population-based survey. Participants Sixty-six clusters of 50 people 50 years of age or older were selected by probability proportionate to size sampling. Households within clusters were selected through compact segment sampling. Methods Participants underwent visual acuity (VA) screening and diagnosis of cause of visual impairment by an ophthalmologist. Participants were classed as having diabetes if they had a previous diagnosis of diabetes, were receiving treatment for glucose control, or had a random blood glucose level of more than 200 mg/dl. Participants with diabetes were assessed for DR using dilated clinical examination (direct and indirect ophthalmoscope) and 1 dilated digital fundus photograph per eye (graded by an ophthalmologist during the survey and regraded by a retinal specialist—"reference standard") following the Scottish DR grading protocol. Main Outcome Measures Prevalence of blindness (VA Results Three thousand three hundred subjects were selected, of whom 2864 (87%) were examined. The estimated prevalence of bilateral blindness was 2.3% (95% confidence interval [CI], 1.7%–2.9%). Cataract was the leading cause of bilateral blindness (63%), followed by posterior segment diseases (24%), which included DR (8% of blindness). The prevalence of diabetes was 21% (19.5%–23.1%). Among participants with diabetes, the prevalence of DR (in at least 1 eye) was 38.9% (95% CI, 33.7%–44.1%). The prevalence of sight-threatening DR (STDR; defined as proliferative DR, referable maculopathy, or both) was 21.0% (95% CI, 16.7%–25.3%). Agreement with the reference standard was good for any retinopathy and STDR for the clinical examination (κ = 0.80 and 0.79, respectively) and the photograph graded during the survey (κ = 0.80 and 0.82, respectively). Conclusions The prevalence of diabetes and DR in Chiapas was high. Including the DR component was possible, but added considerably to the cost and complexity of the survey, and so would be warranted only if a high prevalence of diabetes is expected and if resources and time permit. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.
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Rapid Assessment of avoidable blindness in the occupied palestinian territories
PLOS ONE, 2010Co-Authors: Far Chiang, Hannah Kuper, Robert Lindfield, Tiarnan D L Keenan, Nael Seyam, Denise Magauran, Nasrallah Khalilia, Habes Batta, Ziad Abdeen, Nicholas SargentAbstract:Background There are no recent data on the prevalence and causes of blindness in the Occupied Palestinian Territories. The aim of our study was to estimate the prevalence and causes of blindness and visual impairment in the population aged 50 years and above in the Occupied Palestinian Territories using the Rapid Assessment of Avoidable Blindness (RAAB) survey method.
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Rapid Assessment of avoidable blindness in kunming china
Ophthalmology, 2008Co-Authors: Jennifer Ly Yip, Hannah KuperAbstract:Objective To estimate the magnitude and causes of visual impairment (VI) in people aged ≥ 50 years in Kunming using the Rapid Assessment for Avoidable Blindness methodology, and to assess the prevalence of a pupillary defect in participants diagnosed as cataract visually impaired. Design Population-based cross-sectional survey. Participants We enrolled 2760 residents of Kunming prefecture in southwest China, >50 years of age. Methods Forty-six clusters of 60 people were selected based on population proportional to size. Households from each cluster were selected using compact segment sampling (CSS) or quota sampling when CSS was not feasible. Visual acuity (VA) was assessed using a tumbling E chart. Lens status and cause of VI were determined by ophthalmologists using direct ophthalmoscopy through a dilated pupil where necessary. The pupillary reaction was assessed on undilated pupils when VI was detected. Main Outcome Measures Prevalence of blindness (VA Results Of 2760 enumerated residents, 2588 were examined. The sample prevalence of bilateral blindness was 3.7% (95% confidence interval [CI], 2.8–4.6%). The prevalence of SVI was 3.0% (95% CI, 2.2–3.8%), and of VI was 9.1% (95% CI, 7.5–10.7%). The main cause of blindness was cataract (63.2% of blindness), followed by nontrachomatous corneal scar (14.7%), glaucoma (7.4%), and other posterior segment disease/neurologic disorders (4.2%). A pupillary defect was detected in 16% of those diagnosed with cataract VI. The cataract surgical coverage in the bilaterally blind was 58.9%, and 45% of operated eyes had good outcome with available correction (VA>6/18). The main barrier to cataract surgery was cost. Conclusions Cataract remains the most important cause of preventable blindness in this poor region of China, and affordable provision of surgery would help to address this problem. Some cases of cataract blindness may not be preventable owing to preexisting comorbidity, as detected by the presence of a pupillary defect.
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Rapid Assessment of avoidable blindness in western rwanda blindness in a postconflict setting
PLOS Medicine, 2007Co-Authors: Wanjiku Mathenge, Hans Limburg, John Nkurikiye, Hannah KuperAbstract:Background The World Health Organization estimates that there were 37 million blind people in 2002 and that the prevalence of blindness was 9% among adults in Africa aged 50 years or older. Recent surveys indicate that this figure may be overestimated, while a survey from southern Sudan suggested that postconflict areas are particularly vulnerable to blindness. The aim of this study was to conduct a Rapid Assessment for Avoidable Blindness to estimate the magnitude and causes of visual impairment in people aged ≥ 50 y in the postconflict area of the Western Province of Rwanda, which includes one-quarter of the population of Rwanda. Methods and Findings Clusters of 50 people aged ≥ 50 y were selected through probability proportionate to size sampling. Households within clusters were selected through compact segment sampling. Visual acuity (VA) was measured with a tumbling “E” chart, and those with VA below 6/18 in either eye were examined by an ophthalmologist. The teams examined 2,206 people (response rate 98.0%). The unadjusted prevalence of bilateral blindness was 1.8% (95% confidence interval [CI] 1.2%–2.4%), 1.3% (0.8%–1.7%) for severe visual impairment, and 5.3% (4.2%–6.4%) for visual impairment. Most bilateral blindness (65%) was due to cataract. Overall, the vast majority of cases of blindness (80.0%), severe visual impairment (67.9%), and visual impairment (87.2%) were avoidable (i.e.. due to cataract, refractive error, aphakia, trachoma, or corneal scar). The cataract surgical coverage was moderate; 47% of people with bilateral cataract blindness (VA < 3/60) had undergone surgery. Of the 29 eyes that had undergone cataract surgery, nine (31%) had a best-corrected poor outcome (i.e., VA < 6/60). Extrapolating these estimates to Rwanda's Western Province, among the people aged 50 years or above 2,565 are expected to be blind, 1,824 to have severe visual impairment, and 8,055 to have visual impairment. Conclusions The prevalence of blindness and visual impairment in this postconflict area in the Western Province of Rwanda was far lower than expected. Most of the cases of blindness and visual impairment remain avoidable, however, suggesting that the implementation of an effective eye care service could reduce the prevalence further.
Marcia Vernon - One of the best experts on this subject based on the ideXlab platform.
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multivariate approach to the measurement of tomato maturity and gustatory attributes and their Rapid Assessment by vis nir spectroscopy
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Alain Clement, Martine Dorais, Marcia VernonAbstract:Standard methods for determining quality and maturity are time- and labor-consuming and generally measure individual criteria at a specific time, without considering relationships among quality parameters. To propose a Rapid and nondestructive analysis method describing multidimensional quality variables, an experiment was undertaken with mature green to overripe tomato fruits found on the North American retail markets. Factor analysis was used to analyze results. Four factors were considered, representing 81% of total variance. The first one, tomato maturity stage (TMS), is related to color, lycopene content, firmness, titratable acidity (TA), pH, and soluble solids (SS). Nondestructive Rapid Assessment by vis−NIR spectroscopy can predict TMS (r2 = 0.93). Factors 2 and 3 are both related to taste and should be considered simultaneously. Factor 2, called the gustatory index, is linked to electrical conductivity (EC), SS, TA, and pH. Factor 3, defined by SS, can be directly measured by a refractometer. Fou...
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multivariate approach to the measurement of tomato maturity and gustatory attributes and their Rapid Assessment by vis nir spectroscopy
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Alain Clement, Martine Dorais, Marcia VernonAbstract:Standard methods for determining quality and maturity are time- and labor-consuming and generally measure individual criteria at a specific time, without considering relationships among quality parameters. To propose a Rapid and nondestructive analysis method describing multidimensional quality variables, an experiment was undertaken with mature green to overripe tomato fruits found on the North American retail markets. Factor analysis was used to analyze results. Four factors were considered, representing 81% of total variance. The first one, tomato maturity stage (TMS), is related to color, lycopene content, firmness, titratable acidity (TA), pH, and soluble solids (SS). Nondestructive Rapid Assessment by vis−NIR spectroscopy can predict TMS (r2 = 0.93). Factors 2 and 3 are both related to taste and should be considered simultaneously. Factor 2, called the gustatory index, is linked to electrical conductivity (EC), SS, TA, and pH. Factor 3, defined by SS, can be directly measured by a refractometer. Fou...
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multivariate approach to the measurement of tomato maturity and gustatory attributes and their Rapid Assessment by vis nir spectroscopy
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Alain Clement, Martine Dorais, Marcia VernonAbstract:Standard methods for determining quality and maturity are time- and labor-consuming and generally measure individual criteria at a specific time, without considering relationships among quality parameters. To propose a Rapid and nondestructive analysis method describing multidimensional quality variables, an experiment was undertaken with mature green to overripe tomato fruits found on the North American retail markets. Factor analysis was used to analyze results. Four factors were considered, representing 81% of total variance. The first one, tomato maturity stage (TMS), is related to color, lycopene content, firmness, titratable acidity (TA), pH, and soluble solids (SS). Nondestructive Rapid Assessment by vis-NIR spectroscopy can predict TMS (r(2)=0.93). Factors 2 and 3 are both related to taste and should be considered simultaneously. Factor 2, called the gustatory index, is linked to electrical conductivity (EC), SS, TA, and pH. Factor 3, defined by SS, can be directly measured by a refractometer. Four categories of taste are proposed; the most desirable one ranks high both in soluble solids (above 4.5 degrees Brix) and in gustatory index (above 0). It was not possible to measure the gustatory index by vis-NIR spectroscopy (r(2)=0.17), but it can be estimated by EC, using a simple formula. The proposed limit between high and low gustatory index then corresponds to an EC of 5.4 mS/cm. Factor 4, variety, mostly discriminates the pink tomato type and field-grown samples from other varieties.
Serge Planes - One of the best experts on this subject based on the ideXlab platform.
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Rapid Assessment of non indigenous species in the era of the edna barcoding a mediterranean case study
Estuarine Coastal and Shelf Science, 2017Co-Authors: Serge Planes, Alba ArduraAbstract:Abstract With only a narrow opening through the Gibraltar and Suez Canals, the Mediterranean Sea is one of the largest semi-enclosed seas. The marine flora and fauna are some of the richest in the world, relative to its size, particularly in the coastal habitats, which are also characterized by numerous endemic species although the introduction of non-indigenous species threatens its rich and unique biodiversity. Following the opening of the Suez Canal, and in combination with shipping and aquaculture activities, non-indigenous species (NIS) introduction has had measurable impacts on the Mediterranean. Lagoon ecosystems along the French coastline, with approx. 100 NIS identified, are considered hot-spot areas for these species. Rapid Assessment sampling for sessile benthic species together with DNA barcoding is a Rapid, easy and cheap method to detect non-indigenous species. Two nearby and different ecosystems were sampled for invertebrate species: Saint-Nazaire lagoon, a Special Protection Area within the Natura 2000 Network and Canet port, a marina in a small village. The DNA barcoding tool for species identification was used for confirming the taxonomy. This showed that, despite the Saint-Nazaire Lagoon classification within the Natura 2000 network, it is already contaminated with a single NIS that was found in high densities and is clearly beginning to dominate the system. It is proposed that a Rapid Assessment of the sampled environment and the DNA barcode approach are efficient and can provide sufficient information on the new target species to be used in conservation planning and ongoing management efforts.
Alain Clement - One of the best experts on this subject based on the ideXlab platform.
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multivariate approach to the measurement of tomato maturity and gustatory attributes and their Rapid Assessment by vis nir spectroscopy
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Alain Clement, Martine Dorais, Marcia VernonAbstract:Standard methods for determining quality and maturity are time- and labor-consuming and generally measure individual criteria at a specific time, without considering relationships among quality parameters. To propose a Rapid and nondestructive analysis method describing multidimensional quality variables, an experiment was undertaken with mature green to overripe tomato fruits found on the North American retail markets. Factor analysis was used to analyze results. Four factors were considered, representing 81% of total variance. The first one, tomato maturity stage (TMS), is related to color, lycopene content, firmness, titratable acidity (TA), pH, and soluble solids (SS). Nondestructive Rapid Assessment by vis−NIR spectroscopy can predict TMS (r2 = 0.93). Factors 2 and 3 are both related to taste and should be considered simultaneously. Factor 2, called the gustatory index, is linked to electrical conductivity (EC), SS, TA, and pH. Factor 3, defined by SS, can be directly measured by a refractometer. Fou...
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multivariate approach to the measurement of tomato maturity and gustatory attributes and their Rapid Assessment by vis nir spectroscopy
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Alain Clement, Martine Dorais, Marcia VernonAbstract:Standard methods for determining quality and maturity are time- and labor-consuming and generally measure individual criteria at a specific time, without considering relationships among quality parameters. To propose a Rapid and nondestructive analysis method describing multidimensional quality variables, an experiment was undertaken with mature green to overripe tomato fruits found on the North American retail markets. Factor analysis was used to analyze results. Four factors were considered, representing 81% of total variance. The first one, tomato maturity stage (TMS), is related to color, lycopene content, firmness, titratable acidity (TA), pH, and soluble solids (SS). Nondestructive Rapid Assessment by vis−NIR spectroscopy can predict TMS (r2 = 0.93). Factors 2 and 3 are both related to taste and should be considered simultaneously. Factor 2, called the gustatory index, is linked to electrical conductivity (EC), SS, TA, and pH. Factor 3, defined by SS, can be directly measured by a refractometer. Fou...
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multivariate approach to the measurement of tomato maturity and gustatory attributes and their Rapid Assessment by vis nir spectroscopy
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Alain Clement, Martine Dorais, Marcia VernonAbstract:Standard methods for determining quality and maturity are time- and labor-consuming and generally measure individual criteria at a specific time, without considering relationships among quality parameters. To propose a Rapid and nondestructive analysis method describing multidimensional quality variables, an experiment was undertaken with mature green to overripe tomato fruits found on the North American retail markets. Factor analysis was used to analyze results. Four factors were considered, representing 81% of total variance. The first one, tomato maturity stage (TMS), is related to color, lycopene content, firmness, titratable acidity (TA), pH, and soluble solids (SS). Nondestructive Rapid Assessment by vis-NIR spectroscopy can predict TMS (r(2)=0.93). Factors 2 and 3 are both related to taste and should be considered simultaneously. Factor 2, called the gustatory index, is linked to electrical conductivity (EC), SS, TA, and pH. Factor 3, defined by SS, can be directly measured by a refractometer. Four categories of taste are proposed; the most desirable one ranks high both in soluble solids (above 4.5 degrees Brix) and in gustatory index (above 0). It was not possible to measure the gustatory index by vis-NIR spectroscopy (r(2)=0.17), but it can be estimated by EC, using a simple formula. The proposed limit between high and low gustatory index then corresponds to an EC of 5.4 mS/cm. Factor 4, variety, mostly discriminates the pink tomato type and field-grown samples from other varieties.
Jennifer Ly Yip - One of the best experts on this subject based on the ideXlab platform.
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Field test of the Rapid Assessment of Hearing Loss survey protocol in Ntcheu district, Malawi.
'Informa UK Limited', 2020Co-Authors: Bright Tess, Phiri Mwanaisha, Mulwafu Wakisa, Jennifer Ly Yip, Jiang Fan, Swanepoel De Wet, Kuper Hannah, Mactaggart Islay, Polack SarahAbstract:Objective: (1) To test the feasibility of the Rapid Assessment of Hearing Loss (RAHL) survey protocol in Malawi (Ntcheu); (2) To estimate the prevalence and probable causes of hearing loss (adults 50+).Design: Cross-sectional population-based survey.Study sample: Clusters (n = 38) were selected using probability-proportionate-to-size-sampling. Within each cluster, 30 people aged 50+ were selected using compact-segment-sampling. All participants completed smartphone-based audiometry (hearTest). Prevalence was estimated using WHO definitions (PTA of thresholds 0.5, 1, 2, 4 kHz in the better ear of >25 dB HL (any) and >40 dB HL (≥moderate)). Otoscopy and questionnaire were used to assess probable causes. Participants with hearing loss and/or ear disease were asked about care-seeking and barriers.Results: Four teams completed the survey in 24 days. 1080 of 1153 (93.7%) participants were examined. The median time to complete the protocol was 24 min/participant. Prevalence of hearing loss was 35.9% (95% CI = 31.6-40.2) (any level); and 10.0% (95% CI = 7.9-12.5) (≥moderate). The majority was classified as probable sensorineural. Nearly one third of people (30.9%) needed diagnostic audiology services and possible hearing aid fitting. Hearing aid coverage was
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Rationale and feasibility of a combined Rapid Assessment of avoidable blindness and hearing loss protocol.
'Public Library of Science (PLoS)', 2020Co-Authors: Igh Tess, Ia Mccormick, Phiri Mwanaisha, Mulwafu Wakisa, Urto Matthew, Polack Sarah, Mactagga Islay, Jennifer Ly Yip, De We Swanepoel, Kupe HannahAbstract:PURPOSE: This study has two main objectives: 1) to assess the value of combining the Rapid Assessment of avoidable blindness (RAAB) and the recently developed Rapid Assessment of hearing loss (RAHL) based on existing population-based data from Cameroon andIndia; 2) to test the feasibility of a combined RAAB-RAHL protocol. METHODS: A secondary data analysis of population-based disability surveys in India and Cameroon (in 2013-2014) was conducted, focussing on people aged 50+. Hearing impairment (HI) was defined as pure tone average of ≥41dB (better ear).Visual impairment (VI) was defined as presenting visual acuity of
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Rapid Assessment of avoidable blindness in kunming china
Ophthalmology, 2008Co-Authors: Jennifer Ly Yip, Hannah KuperAbstract:Objective To estimate the magnitude and causes of visual impairment (VI) in people aged ≥ 50 years in Kunming using the Rapid Assessment for Avoidable Blindness methodology, and to assess the prevalence of a pupillary defect in participants diagnosed as cataract visually impaired. Design Population-based cross-sectional survey. Participants We enrolled 2760 residents of Kunming prefecture in southwest China, >50 years of age. Methods Forty-six clusters of 60 people were selected based on population proportional to size. Households from each cluster were selected using compact segment sampling (CSS) or quota sampling when CSS was not feasible. Visual acuity (VA) was assessed using a tumbling E chart. Lens status and cause of VI were determined by ophthalmologists using direct ophthalmoscopy through a dilated pupil where necessary. The pupillary reaction was assessed on undilated pupils when VI was detected. Main Outcome Measures Prevalence of blindness (VA Results Of 2760 enumerated residents, 2588 were examined. The sample prevalence of bilateral blindness was 3.7% (95% confidence interval [CI], 2.8–4.6%). The prevalence of SVI was 3.0% (95% CI, 2.2–3.8%), and of VI was 9.1% (95% CI, 7.5–10.7%). The main cause of blindness was cataract (63.2% of blindness), followed by nontrachomatous corneal scar (14.7%), glaucoma (7.4%), and other posterior segment disease/neurologic disorders (4.2%). A pupillary defect was detected in 16% of those diagnosed with cataract VI. The cataract surgical coverage in the bilaterally blind was 58.9%, and 45% of operated eyes had good outcome with available correction (VA>6/18). The main barrier to cataract surgery was cost. Conclusions Cataract remains the most important cause of preventable blindness in this poor region of China, and affordable provision of surgery would help to address this problem. Some cases of cataract blindness may not be preventable owing to preexisting comorbidity, as detected by the presence of a pupillary defect.
