BAT: block analytics tool integrated with blockchain based IoT platform

The Internet of Things (IoT) is currently the paradigm of connectivity and driving force behind the state-of-art applications and services. However, the exponential growth of the number of IoT devices and services, their distributed nature, and scarcity of resources has increased the number of security and privacy concerns ranging from the risks of unauthorized data alterations to the potential discrimination enabled by data analytics over sensitive information. A blockchain based IoT-platform is introduced to address these issues. Built upon the tamper-proof architecture, the access management mechanisms ensure the authenticity and integrity of data. Moreover, a novel approach called Block Analytics Tool (BAT), integrated with the platform is proposed to analyze and make predictions on data stored on blockchain. BAT enables the data-analysis applications to be developed using the data stored in the platform in an optimized manner acting as an interface to off-chain processing. A pharmaceutical supply chain is the use case scenario to show the functionality of the proposed platform. Furthermore, a model to forecast the demand of the pharmaceutical drugs is investigated using a real-world data set to demonstrate the functionality of BAT. Finally, the performance of BAT integrated with the platform is evaluated

Impact of blindness, visual impairment and cataract surgery on quality of life and visual functioning among adults aged 40 years and above in Sri Lanka

Aims To assess associations of visual function (VF) and quality of life (QOL) by presenting visual acuity (PVA) and causes of blindness and visual impairment. Methods Multi-stage cluster random sampling was used to identify a nationally representative sample of persons aged ≥ 40 years in Sri Lanka. Previously validated VF and QOL measurement instruments were administered to participants who were blind or severely visually impaired due to cataract, or refractive errors, those with moderate severe visual impairment of any cause and a sample of those with normal/near normal vision (VA ≥6/12 in the better eye). Questionnaires were also administered to persons who had undergone cataract surgery in one or both eyes and had a post-operative vision ≥ 6/60. Results The Cronbach α coefficients showed that the VF and QOL subscales had satisfactory internal consistency and reliability. Mean VF/QOL scores of individuals who were blind (presenting VA < 3/60 in the better eye) were significantly lower and the maximal difficulty in performing VF tasks and QOL-related activities. Persons visually impaired from cataract had the greatest difficulty in performing VF activities and QOL domains on all the items in the VF and QOL questionnaires. Persons operated for cataract had much better VF/QOL outcomes compared to those who were visually impaired due to cataract. Conclusions VF and QOL self-reported questionnaires are very useful to monitor patient-reported functional benefit from blindness control interventions in low and middle- income countries like Sri Lanka

Prevalence and determinants of self-reported ocular morbidity and utilization of eye services in Sri Lanka: results from a national population-based survey

Introduction Data on ocular morbidity is essential for planning primary and referral eye care services. Objectives Determine the prevalence and causes of self-reported ocular morbidity and eye care service utilization in Sri Lanka among adults ≥ 40 years of age. Methods Multistage, stratified, cluster random sampling was used to select a nationally representative sample aged ≥40 years. All participants were administered a questionnaire to assess ocular morbidity they had experienced in the previous month and the pattern of service utilization for reported eye problems. The interviews were conducted by a team of trained investigators at the clinical examination site before they underwent an eye examination. Results 5779 of those presenting for a clinical examination were interviewed among 6713 enumerated (86.1%). The prevalence of self-reported ocular morbidity was 89.9% [95% Confidence Interval (CI): 89.0–90.6%]. Near vision impairment was the commonest problem reported (72.1%; 95% CI: 70.8–73.3%) followed by distance vision impairment (36.2%; 95% CI: 34.9-37.5%). Among those reporting an eye problem, 31.4% sought treatment. 49.4% of those seeking care utilized private facilities. Financial constraints, perceptions that the condition was not serious or had insufficient impact on day-to-day tasks were the most important reasons for not accessing care. Conclusions Ocular morbidities are common in the Sri Lanka population; however utilization of services is relatively low, particularly for asymptomatic illnesses. It is important that the service planners take into account geographical and social inequalities and focus the services on underserviced areas and disadvantaged social groups

Prevalence and determinants of age-related macular degeneration in central Sri Lanka: the Kandy Eye Study

Aims To determine the prevalence, associations and risk factors for age-related macular degeneration (ARMD) in central Sri Lanka. Methods The study was a population-based, cross-sectional survey of residents aged ≥40 years in rural Sri Lanka. ARMD was assessed on dilated fundoscopy using the International Age-Related Maculopathy Epidemiology Study Group classification system. Results Of the 1721 subjects identified, 1375 participated (79.9%). Of the participants, 1013 were aged ≥50 years (73.6%). The prevalence of any ARMD (adjusted for study design) was 4.72 (95% CI 2.22 to 7.20)% with 3.82 (95% CI 1.60 to 6.04)% early ARMD and 1.70 (95% CI 0.14 to 3.27)% late ARMD. Age (p<0.001) and Sinhalese ethnicity (p = 0.016) were significantly associated with ARMD. Men had a tendency toward a higher prevalence of ARMD than women, although this was not statistically significant (p = 0.081). Ocular risk factors such as cortical cataract (p = 0.024) and pseudophakia (p = 0.003) were associated with ARMD on the univariate but not multivariate analyses. Illiteracy and the identification of social supports were significantly associated with ARMD on univariate analyses. However, only social support was statistically significant after multivariate analysis (p = 0.024). Conclusions Although the prevalence of ARMD is slightly lower in Sri Lanka than surrounding regions, it contributes to a higher proportion of visual impairment, including blindness. Risk factors include age and Sinhalese ethnicity.L A Goold, K Edussuriya, S Sennanayake, T Senaratne, D Selva, T R Sullivan, R J Casso

Prevalence and visual outcomes of cataract surgery and cataract surgical coverage in Sri Lanka: findings from the National Blindness and Visual Impairment Survey

Introduction Cataract surgical coverage and visual acuity outcomes are important population level indicators for monitoring access to and the quality of cataract surgery, allowing subgroups with poorer access to be identified. Data on these indicators are not available for Sri Lanka at national level. Objectives Determine cataract surgical coverage and the outcomes of cataract surgery in a nationally representative sample of adults aged ≥40 years. Methods Cluster random sampling with proportionate to size procedures was used. All participants were interviewed to obtain data on education level, movable assets, and the year and place of cataract surgery, if applicable. Presenting and best corrected visual acuities were measured. All participants underwent slit lamp examination, including a dilated examination of the fundus. Cataract surgical coverage was calculated at the person level vision of <3/30, <6/60 and <6/18. Outcomes of cataract surgery were categorized as good (6/18 or better), borderline (<6/18-6/60) or poor (<6/60). Results A total of 345 persons among the 5,779 participants who were examined had undergone cataract surgery in one or both eyes (486 eyes). Cataract surgical coverage, which was high overall 85.4% for vision <3/60; 79.1% for vision <6/60), was significantly higher in younger age groups (Odds Ratio [OR] 5.65, 95% confidence interval [CI] 1.42-22.52), those in urban areas (OR 2.8, 95% CI 1.01-7.74) those with higher socio-economic status (OR 6.0; 95% CI 1.96-18.4). Coverage ranged from 60% in Uva Province to 100% in Southern Province. 59.7% of eyes had good outcomes at presentation increasing to 75.1% with correction. Conclusions Cataract surgery indicators for Sri Lanka are good, being better than most other Asian countries. Services should target those living in underserved Provinces

Prevalence, causes, magnitude and risk factors of visual impairment and blindness in Sri Lanka

Introduction There is paucity of data on the epidemiology of visual impairment in Sri Lanka. Objectives Estimate the prevalence and determine causes and risk factors of visual impairment among adults aged ≥40 years in Sri Lanka. Methods Multistage, stratified, cluster random sampling was used to select a nationally representative sample aged ≥40 years. All participants underwent vision testing, autorefraction and a basic eye examination. Participants with a presenting acuity of <6/12 in either eye underwent detailed eye examination, assessment of best-corrected acuity if required, and a cause of visual loss assigned. Results 5,779 of those enumerated (6,713) were examined (response rate 86.1%). The prevalence of blindness was 1.7% (95% confidence interval [CI]: 1.3-1.99%) and low vision was 17% (95% CI: 16.0-18.0%). Cataract (66.7%) and uncorrected refractive errors (12.5%) were the commonest causes of blindness. Uncorrected refractive errors (62.4%) and cataract (24.2%) were the commonest causes of low vision. Blindness was significantly higher in older age groups (OR 132.4: 95% Cl 11.7-149.3), those residing in the North Central (OR-12.5), North (OR-12.0), North West (OR-7.3), Eastern (OR-6.7), Western (OR-5.3) and Uva provinces (OR-5.3) compared to the Southern, and in those educated up to and including secondary school (OR 2.3: 95% CI 1.5- 3.17). Gender and socio-economic status were not significant after adjusting. Conclusions The prevalence of blindness in Sri Lanka is lower than in other South Asian countries and most causes are avoidable. Access to eye care needs to improve amongst the aged, those less educated and those in provinces with higher blindness risk

Prevalence and types of refractive errors, and spectacle coverage in Sri Lankan adults: The Sri Lanka National survey of blindness and visual impairment

Introduction Uncorrected refractive errors are the commonest cause of visual impairment globally. Despite this, the proportion of affected individuals who wear spectacles can be low, particularly in low and middle- income countries. No data were available for Sri Lanka. Objectives To estimate the prevalence of refractive errors and investigate their risk factors among adults aged 40 years and above. Another purpose was to calculate spectacle coverage and identify subgroups with low coverage. Methods Cluster random sampling was used to obtain a nationally representative sample. Presenting distance visual acuity was measured using a logMAR chart, with distance spectacle correction if usually worn. All underwent autorefraction and an optician measured best-corrected visual acuity after subjective refraction. Participants who had undergone cataract surgery were excluded. Spectacle coverage was assessed amongst participants with a visual acuity of <6/12 in the better eye due to refractive error who attended the examination site with spectacles. Results 5,779/6,713 (86.1%) enumerated adults were examined; 5,179 had refraction data. 67% had a refractive error: hyperopia 49.6%; myopia 17.4%. Refractive errors increased with age. Being aged 60 years and above and Sinhala ethnic group were independent risk factors. Spectacle coverage was 17.7% overall, being lower in females and the non-literate. Based on the findings, 1.66 million adults require spectacles for distance correction. Conclusions Refractive errors are very common in Sri Lankan adults, and there is a large unmet need for spectacles. Affordable services for refractive errors need to be scaled up, focusing on the most underserved subgroups in the population

Rapid assessment of visual impairment (RAVI) in marine fishing communities in South India - study protocol and main findings

<p>Abstract</p> <p>Background</p> <p>Reliable data are a pre-requisite for planning eye care services. Though conventional cross sectional studies provide reliable information, they are resource intensive. A novel rapid assessment method was used to investigate the prevalence and causes of visual impairment and presbyopia in subjects aged 40 years and older. This paper describes the detailed methodology and study procedures of Rapid Assessment of Visual Impairment (RAVI) project.</p> <p>Methods</p> <p>A population-based cross-sectional study was conducted using cluster random sampling in the coastal region of Prakasam district of Andhra Pradesh in India, predominantly inhabited by fishing communities. Unaided, aided and pinhole visual acuity (VA) was assessed using a Snellen chart at a distance of 6 meters. The VA was re-assessed using a pinhole, if VA was < 6/12 in either eye. Near vision was assessed using N notation chart binocularly. Visual impairment was defined as presenting VA < 6/18 in the better eye. Presbyopia is defined as binocular near vision worse than N8 in subjects with binocular distance VA of 6/18 or better.</p> <p>Results</p> <p>The data collection was completed in <12 weeks using two teams each consisting of one paramedical ophthalmic personnel and two community eye health workers. The prevalence of visual impairment was 30% (95% CI, 27.6-32.2). This included 111 (7.1%; 95% CI, 5.8-8.4) individuals with blindness. Cataract was the leading cause of visual impairment followed by uncorrected refractive errors. The prevalence of blindness according to WHO definition (presenting VA < 3/60 in the better eye) was 2.7% (95% CI, 1.9-3.5).</p> <p>Conclusion</p> <p>There is a high prevalence of visual impairment in marine fishing communities in Prakasam district in India. The data from this rapid assessment survey can now be used as a baseline to start eye care services in this region. The rapid assessment methodology (RAVI) reported in this paper is robust, quick and has the potential to be replicated in other areas.</p

Identification of novel mutations causing pediatric cataract in Bhutan, Cambodia, and Sri Lanka

Background: Pediatric cataract is an important cause of blindness and visual impairment in children. A large proportion of pediatric cataracts are inherited, and many genes have been described for this heterogeneous Mendelian disease. Surveys of schools for the blind in Bhutan, Cambodia, and Sri Lanka have identified many children with this condition and we aimed to identify the genetic causes of inherited cataract in these populations.Methods: We screened, in parallel, 51 causative genes for inherited cataracts in 33 probands by Ampliseq enrichment and sequencing on an Ion Torrent PGM. Rare novel protein coding variants were assessed for segregation in family members, where possible, by Sanger sequencing.Results: We identified 24 rare (frequency Conclusion: This study found that 20%-30% of patients in these countries have a mutation in a known cataract causing gene, which is considerably lower than the 60%-70% reported in Caucasian cohorts. This suggests that additional cataract genes remain to be discovered in this cohort of Asian pediatric cataract patients

Visual impairment among weaving communities in Prakasam district in South India.

PURPOSE: To assess the prevalence and causes of visual impairment in weaving communities in Prakasam district in South India state of Andhra Pradesh. METHODS: Using Rapid Assessment of Visual Impairment (RAVI) methodology, a population based cross-sectional study was conducted. A two-stage sampling strategy was used to select 3000 participants aged ≥40 years. Visual Acuity (VA) was assessed using a tumbling E chart and ocular examinations were performed by trained Para medical ophthalmic personnel. A questionnaire was used to collect personal and demographic information. Blindness and moderate Visual Impairment (VI) was defined as presenting VA <6/60 and <6/18 to 6/60 respectively. VI included blindness and moderate VI. RESULTS: 2848 of 3000 enumerated subjects (94.0%) participated. 39% were in 40-49 years age group and 11.8% were aged ≥70 years, 55% were women and nearly half of them had no formal education. 400 (14%; 95% CI: 12.8-15.3) subjects had VI, including blindness in 131 (4.6%; 95% CI: 3.8-5.4) and moderate VI in 269 (9.4%; 95% CI: 8.3-10.5) individuals. On applying multiple logistic regression, VI was significantly associated with older age and no formal education. Though the odds of having VI were higher in females, it was of borderline statistical significance (p = 0.06). Refractive error was the leading cause of all VI followed by cataract (56%). However, refractive errors were the leading cause of moderate VI (73.2%) and cataract was the leading cause of blindness (62.6%). 'Cannot afford the cost of services' was the leading barrier for utilization of eye care services (47%). CONCLUSIONS: There is a significant burden of VI in weaving communities in Andhra Pradesh, India most of which is avoidable. With this information as baseline, services need to be streamlined to address this burden