A novel Automatic Optic Disc and Cup Image Segmentation System for Diagnosing Glaucoma using RIGA dataset

The optic nerve head (ONH) of the retina is a very important landmark of the fundus and is altered in optic nerve pathology especially glaucoma. Numerous imaging systems are available to capture the retinal fundus and from which some structural parameters can be inferred the retinal fundus camera is one of the most important tools used for this purpose. Currently, the ONH structure examination of the fundus images is conducted by the professionals only by observation. It should be noted that there is a shortage of highly trained professional worldwide. Therefore a reliable and efficient optic disc and cup localization and segmentation algorithms are important for automatic eye disease screening and also for monitoring the progression/remission of the disease Thus in order to develop a system, a retinal fundus image dataset is necessary to train and test the new software systems. The methods for diagnosing glaucoma are reviewed in the first chapter. Various datasets of retinal fundus images that are publically available currently are described and discussed. In the second chapter the techniques for the optic disc and cup segmentations available in the literature is reviewed. While in the third chapter a unique retinal fundus image dataset, called RIGA (retinal images for glaucoma analysis) is presented. In the dataset, the optic disc and cup boundaries are annotated manually by 6 ophthalmologists (glaucoma professionals) independently for total of 4500 images in order to obtain a comprehensive view point as well as to see the variation and agreement between these professionals. Based upon these evaluations, some of the images were filtered based on a statistical analysis in order to increase the reliability. The new optic disc and cup segmentation methodologies are discussed in the fourth chapter. The process starts with a preprocessing step based on a reliable and precise algorithm. Here an Interval Type-II fuzzy entropy based thresholding scheme along with Differential Evolution was applied to determine the location of the optic disc in order to determine the region of interest instead of dealing with the entire image. Then, the processing step is discussed. Two algorithms were applied: one for optic disc segmentation based on an active contour model implemented by level set approach, and the second for optic cup segmentation. For this thresholding was applied to localize the disc. The disc and cup area and centroid are then calculated in order to evaluate them based on the manual annotations of areas and centroid for the filtered images based on the statistical analysis. In the fifth chapter, after segmenting the disc and cup, the clinical parameters in diagnosis of glaucoma such as horizontal and vertical cup to disc ratio (HCDR) and (VCDR) are computed automatically as a post processing step in order to compare the results with the six ophthalmologist’s manual annotations results. The thesis is concluded in chapter six with discussion of future plans

An Automatic Image Processing System for Glaucoma Screening

Horizontal and vertical cup to disc ratios are the most crucial parameters used clinically to detect glaucoma or monitor its progress and are manually evaluated from retinal fundus images of the optic nerve head. Due to the rarity of the glaucoma experts as well as the increasing in glaucoma’s population, an automatically calculated horizontal and vertical cup to disc ratios (HCDR and VCDR, resp.) can be useful for glaucoma screening. We report on two algorithms to calculate the HCDR and VCDR. In the algorithms, level set and inpainting techniques were developed for segmenting the disc, while thresholding using Type-II fuzzy approach was developed for segmenting the cup. The results from the algorithms were verified using the manual markings of images from a dataset of glaucomatous images (retinal fundus images for glaucoma analysis (RIGA dataset)) by six ophthalmologists. The algorithm’s accuracy for HCDR and VCDR combined was 74.2%. Only the accuracy of manual markings by one ophthalmologist was higher than the algorithm’s accuracy. The algorithm’s best agreement was with markings by ophthalmologist number 1 in 230 images (41.8%) of the total tested images

Global, regional, and national disability-adjusted life-years (DALYs) for 333 diseases and injuries and healthy life expectancy (HALE) for 195 countries and territories, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND: Measurement of changes in health across locations is useful to compare and contrast changing epidemiological patterns against health system performance and identify specific needs for resource allocation in research, policy development, and programme decision making. Using the Global Burden of Diseases, Injuries, and Risk Factors Study 2016, we drew from two widely used summary measures to monitor such changes in population health: disability-adjusted life-years (DALYs) and healthy life expectancy (HALE). We used these measures to track trends and benchmark progress compared with expected trends on the basis of the Socio-demographic Index (SDI). METHODS: We used results from the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 for all-cause mortality, cause-specific mortality, and non-fatal disease burden to derive HALE and DALYs by sex for 195 countries and territories from 1990 to 2016. We calculated DALYs by summing years of life lost and years of life lived with disability for each location, age group, sex, and year. We estimated HALE using age-specific death rates and years of life lived with disability per capita. We explored how DALYs and HALE differed from expected trends when compared with the SDI: the geometric mean of income per person, educational attainment in the population older than age 15 years, and total fertility rate. FINDINGS: The highest globally observed HALE at birth for both women and men was in Singapore, at 75·2 years (95% uncertainty interval 71·9-78·6) for females and 72·0 years (68·8-75·1) for males. The lowest for females was in the Central African Republic (45·6 years [42·0-49·5]) and for males was in Lesotho (41·5 years [39·0-44·0]). From 1990 to 2016, global HALE increased by an average of 6·24 years (5·97-6·48) for both sexes combined. Global HALE increased by 6·04 years (5·74-6·27) for males and 6·49 years (6·08-6·77) for females, whereas HALE at age 65 years increased by 1·78 years (1·61-1·93) for males and 1·96 years (1·69-2·13) for females. Total global DALYs remained largely unchanged from 1990 to 2016 (-2·3% [-5·9 to 0·9]), with decreases in communicable, maternal, neonatal, and nutritional (CMNN) disease DALYs offset by increased DALYs due to non-communicable diseases (NCDs). The exemplars, calculated as the five lowest ratios of observed to expected age-standardised DALY rates in 2016, were Nicaragua, Costa Rica, the Maldives, Peru, and Israel. The leading three causes of DALYs globally were ischaemic heart disease, cerebrovascular disease, and lower respiratory infections, comprising 16·1% of all DALYs. Total DALYs and age-standardised DALY rates due to most CMNN causes decreased from 1990 to 2016. Conversely, the total DALY burden rose for most NCDs; however, age-standardised DALY rates due to NCDs declined globally. INTERPRETATION: At a global level, DALYs and HALE continue to show improvements. At the same time, we observe that many populations are facing growing functional health loss. Rising SDI was associated with increases in cumulative years of life lived with disability and decreases in CMNN DALYs offset by increased NCD DALYs. Relative compression of morbidity highlights the importance of continued health interventions, which has changed in most locations in pace with the gross domestic product per person, education, and family planning. The analysis of DALYs and HALE and their relationship to SDI represents a robust framework with which to benchmark location-specific health performance. Country-specific drivers of disease burden, particularly for causes with higher-than-expected DALYs, should inform health policies, health system improvement initiatives, targeted prevention efforts, and development assistance for health, including financial and research investments for all countries, regardless of their level of sociodemographic development. The presence of countries that substantially outperform others suggests the need for increased scrutiny for proven examples of best practices, which can help to extend gains, whereas the presence of underperforming countries suggests the need for devotion of extra attention to health systems that need more robust support. FUNDING: Bill & Melinda Gates Foundation

Global, regional, and national burden of meningitis, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016

Zunt JR, Kassebaum NJ, Blake N, et al. Global, regional, and national burden of meningitis, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Neurology. 2018;17(12):1061-1082.Background Acute meningitis has a high case-fatality rate and survivors can have severe lifelong disability. We aimed to provide a comprehensive assessment of the levels and trends of global meningitis burden that could help to guide introduction, continuation, and ongoing development of vaccines and treatment programmes. Methods The Global Burden of Diseases, Injuries, and Risk Factors (GBD) 2016 study estimated meningitis burden due to one of four types of cause: pneumococcal, meningococcal, Haemophilus influenzae type b, and a residual category of other causes. Cause-specific mortality estimates were generated via cause of death ensemble modelling of vital registration and verbal autopsy data that were subject to standardised data processing algorithms. Deaths were multiplied by the GBD standard life expectancy at age of death to estimate years of life lost, the mortality component of disability-adjusted life-years (DALYs). A systematic analysis of relevant publications and hospital and daims data was used to estimate meningitis incidence via a Bayesian meta-regression tool. Meningitis deaths and cases were split between causes with meta-regressions of aetiological proportions of mortality and incidence, respectively. Probabilities of long-term impairment by cause of meningitis were applied to survivors and used to estimate years of life lived with disability (YLDs). We assessed the relationship between burden metrics and Socio-demographic Index (SDI), a composite measure of development based on fertility, income, and education. Findings Global meningitis deaths decreased by 21.0% from 1990 to 2016, from 403 012 (95% uncertainty interval [UI] 319426-458 514) to 318 400 (265 218-408 705). Incident cases globally increased from 2.50 million (95% UI 2.19-2.91) in 1990 to 2.82 million (2.46-3.31) in 2016. Meningitis mortality and incidence were dosely related to SDI. The highest mortality rates and incidence rates were found in the peri-Sahelian countries that comprise the African meningitis belt, with six of the ten countries with the largest number of cases and deaths being located within this region. Haemophilus influenzae type b was the most common cause of incident meningitis in 1990, at 780 070 cases (95% UI 613 585-978 219) globally, but decreased the most (-494%) to become the least common cause in 2016, with 397 297 cases (291076-533 662). Meningococcus was the leading cause of meningitis mortality in 1990 (192833 deaths [95% UI 153 358-221 503] globally), whereas other meningitis was the leading cause for both deaths (136 423 [112 682-178 022]) and incident cases (1.25 million [1.06-1.49]) in 2016. Pneumococcus caused the largest number of YLDs (634458 [444 787-839 749]) in 2016, owing to its more severe long-term effects on survivors. Globally in 2016, 1.48 million (1.04-1.96) YLDs were due to meningitis compared with 21.87 million (18.20-28.28) DALYs, indicating that the contribution of mortality to meningitis burden is far greater than the contribution of disabling outcomes. Interpretation Meningitis burden remains high and progress lags substantially behind that of other vaccine-preventable diseases. Particular attention should be given to developing vaccines with broader coverage against the causes of meningitis, making these vaccines affordable in the most affected countries, improving vaccine uptake, improving access to low-cost diagnostics and therapeutics, and improving support for disabled survivors. Substantial uncertainty remains around pathogenic causes and risk factors for meningitis. Ongoing, active cause-specific surveillance of meningitis is crucial to continue and to improve monitoring of meningitis burdens and trends throughout the world. Copyright (C) The Author(s). Published by Elsevier Ltd

Seventy-two-hour emergency department revisits among adults with chronic diseases: a Saudi Arabian study

Anwar E Ahmed,1,2 Doaa A AlBuraikan,2 Hend R Almazroa,2 Manair N Alrajhi,2 Bashayr I ALMuqbil,2 Monirah A Albaijan,1 Majid A Alsalamah,2 Hamdan AL-Jahdali1,2 1King Abdullah International Medical Research Center (KAIMRC), Riyadh, Saudi Arabia; 2King Saud bin Abdulaziz University for Health Sciences, National Guard Health Affairs, Riyadh, Saudi Arabia Background: Despite the increase in adult emergency department (ED) utilization in Saudi Arabia, no studies have evaluated the 72-hour revisits. This study estimates the rate of 72-hour ED revisits and identifies its reasons and predictive factors among adults with chronic diseases. Patients and methods: A hospital-based retrospective study that included 24,206 ED discharges for adults with chronic diseases at the adult ED of King Abdulaziz Medical City, Riyadh between September 13, 2015 and July 29, 2017 was performed. We extracted data on demographic information, reasons for ED visits/revisits, health insurance coverage, weekend ED arrival, and mortality. Results: A sample of 24,206 ED discharges for 19,697 adults with at least one chronic disease was included in the analysis. The rate of 72-hour revisits in this study population was high: 3,144/24,206 (13%) had the first revisit and 319/3,144 (10.1%) had the second ED revisit within 72 hours. Diseases of the circulatory (19%) and genitourinary (15.8%) systems were the major reasons for the first ED revisit. The adjusted relative rate (aRR) of 72-hour ED revisits was higher in adults with chronic diseases and aged ≥60 years (aRR=1.360, 95% CI: 1.41–1.83; P=0.001), patients of female gender (aRR=1.24, 95% CI: 1.09–1.41; P=0.001), patients with health insurance coverage (aRR=4.23, 95% CI: 2.60–6.90; P=0.001), patients arriving to ED on a weekend (aRR=2.13, 95% CI: 1.03–4.41; P=0.041), and new patients (aRR=1.47, 95% CI: 1.25–1.73; P=0.001). Conclusion: The rate of 72-hour revisits is high among adults with chronic diseases. Advancing age, female gender, health insurance coverage, weekend ED arrival, and new patients are the important predictive factors of the high rate of 72-hour revisits. Continuous quality assessment and monitoring of factors related to patients are needed to reduce the frequency of early ED revisits after discharge. Keywords: 72-hour ED revisits, emergency department, KAMC, Saudi Arabi

The obtained classification reports while evaluating the best model on the testing sets.

The obtained classification reports while evaluating the best model on the testing sets.</p

Fruit and vegetable consumption among adults in Saudi Arabia, 2013

Charbel El Bcheraoui,1 Mohammed Basulaiman,2 Mohammad A AlMazroa,2 Marwa Tuffaha,1 Farah Daoud,1 Shelley Wilson,1 Mohammad Y Al Saeedi,2 Faisal M Alanazi,2 Mohamed E Ibrahim,2 Elawad M Ahmed,2 Syed A Hussain,2 Riad M Salloum,2 Omer Abid,2 Mishal F Al-Dossary,2 Ziad A Memish,2 Abdullah A Al Rabeeah,2 Ali H Mokdad1 1Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA; 2Ministry of Health of the Kingdom of Saudi Arabia, Riyadh, Saudi Arabia Background: Dietary risks were the leading risk factors for death worldwide in 2010. However, current national estimates on fruit and vegetable consumption in the Kingdom of Saudi Arabia (KSA) are nonexistent. We conducted a large household survey to inform the Saudi Ministry of Health (MOH) on a major modifiable risk factor: daily consumption of fruits and vegetables. Methods: The Saudi Health Interview Survey is a national multistage survey of individuals aged 15 years or older. It includes questions on sociodemographic characteristics, tobacco consumption, diet, physical activity, health care utilization, different health-related behaviors, and self-reported chronic conditions. We used a backward elimination multivariate logistic regression model to measure association between the Centers for Disease Control and Prevention (CDC)-recommended daily consumption of fruits and vegetables and different factors. Results: Between April and June 2013, a total of 10,735 participants completed the survey. Overall, 2.6% of Saudis aged 15 years or older met the CDC guidelines for daily consumption of fruits and vegetables. The likelihood of meeting the CDC guidelines increased with age; among women; among persons who graduated from elementary or high school or had a higher education; among residents of Makkah, Al Sharqia, Ha&rsquo;il, or Jizan; among those who consumed at least two servings of meat or chicken per day; among those who visited a health care facility for a routine medical exam within the last 3 years; and among those who have been diagnosed with hypertension. Conclusion: We have showed that KSA is in dire need of improving the diet of its population. Our findings call for urgent research to understand the reasons for low fruit and vegetable consumption, focusing on price or preference in order to develop and implement culturally and country-relevant solutions to increase the consumption of fruits and vegetables. Keywords: Kingdom of Saudi Arabia, fruits, vegetables, dietary risks, die

The selected architectures for the performed experiments.

The selected architectures for the performed experiments.</p

A proposed algorithm to maintain the aspect ratio for all generated bounding boxes.

A proposed algorithm to maintain the aspect ratio for all generated bounding boxes.</p

Confusion matrix diagram.

Confusion matrix diagram.</p