Interocular differences of the Pentacam measurements in normal subjects

Purpose: The aim of this study was to determine the interocular differences of the Pentacam corneal measurements in a normal population. Methods: A retrospective analysis was performed on 550 eyes of 275 consecutive subjects evaluated for refractive surgery at the Rassoul Akram Hospital, Iran University of Medical Sciences. A Pentacam Scheimpflug camera was used for corneal measurements. Statistical analysis was performed to determine the normal levels of the difference between the two eyes. Results: One hundred and four men and 171 women with a mean age of 29.1 ± 7.73 years were evaluated. The mean (range) interocular difference was 2.17 (zero to 21) μm for maximum anterior elevation (AEmax), 3.62 (zero to 31) μm for maximum posterior elevation (PEmax), 8.42 (zero to 30) μm for minimum corneal thickness (CTmin), 0.06 (zero to 0.4) mm3 for three millimetre corneal volume (CV3), 0.19 (zero to 1.2) mm3 for five millimetre corneal volume (CV5), 0.44 (zero to 2.9) mm3 for seven millimetre corneal volume (CV7), 0.24 (zero to 2.5) dioptres for the mean keratometry (Km) and 0.39 (zero to 2.5) D for measurements of the corneal dioptric power in the steepest meridian (Kmax). Conclusions: Individuals with differences greater than 17.4 μm in AEmax, 29.1 μm in PEmax, 29.6 μm in CTmin, 2 D in Km, 2.27 D in Kmax, 0.32 in CV3, 1.05 in CV5, and 2.6 in CV7 between eyes represent less than 0.5 per cent of the population. An interocular difference outside the normal range should alert the clinician to examine for other parameters that are more predictive of post-refractive surgical ectasia. © 2009 Optometrists Association Australia

Multilocal programming and applications

Preprint versionMultilocal programming aims to identify all local minimizers of unconstrained or constrained nonlinear optimization problems. The multilocal programming theory relies on global optimization strategies combined with simple ideas that are inspired in deflection or stretching techniques to avoid convergence to the already detected local minimizers. The most used methods to solve this type of problems are based on stochastic procedures and a population of solutions. In general, population-based methods are computationally expensive but rather reliable in identifying all local solutions. In this chapter, a review on recent techniques for multilocal programming is presented. Some real-world multilocal programming problems based on chemical engineering process design applications are described.Fundação para a Ciência e a Tecnologia (FCT

Global Retinoblastoma Presentation and Analysis by National Income Level

Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4) were female. Most patients (n = 3685 84.7%) were from low-and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 62.8%), followed by strabismus (n = 429 10.2%) and proptosis (n = 309 7.4%). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 95% CI, 12.94-24.80, and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 95% CI, 4.30-7.68). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs. © 2020 American Medical Association. All rights reserved

Evaluation of subconjunctival oculusgen implantation as an adjunct to trabeculectomy

Purpose: To evaluate the efficacy and safety of subconjunctival oculusgen implantation when used during trabeculectomy Methods: In this prospective, nonrandomized, interventional case series, 10 eyes of 10 patients with medically uncontrolled open angle glaucoma were enrolled. Conventional fornix based trabeculectomy with implantation of subconjunctival biodegradable collagen implant (oculusgen) was performed in all patients. The preoperative best corrected visual acuity (BCVA), intraocular pressure (IOP) measurement and numbers of antiglaucoma medication were recorded. There were 7 postoperative follow-up visits within 6 months after surgery. After 6 months, follow-up visits were continued every 2-3 months. At each visit, the examination included measurements of BCVA and IOP, slit-lamp biomicroscopy, assessment of cell and flare, bleb evaluation and funduscopy. Any complications were recorded at the end of each examination. Data analysis was performed using SPSS software version 15. Results: Mean duration of follow-up was 11.9 months (range 6-26 months). Mean preoperative IOP was 19.3 mmHg (range 12-25 mmHg) with 2.9 number of IOP lowering medications (range 2-4) and mean postoperative IOP was 15.3 mmHg (range 10-24) at month 6 (P=0.028) and 14.7 (range 10-20) at last visit (P=0.016). Mean IOP lowering medications and IOP reduction after 180 days were 0.4 (range 0-3) (P=0.000) and 4.2 mmHg respectively. Mean IOP lowering medications and IOP reduction at last visit were 0.7 (range 0-3) (P=0.000) and 4.8 mmHg. Overall success at last follow-up was 80. None of the patients experienced systemic or ocular complication related to oculusgen. Conclusion: Trabeculectomy with implantation of oculusgen is a safe and effective surgical method in patients with open angle glaucoma, but longer duration of follow-up in larger number of patients is needed. © 2010 by the Iranian Society of Ophthalmology

Lung functions after correction of scoliosis angle

Background: In this study we evaluated lung volumes, volume changes relative to Cobb angle and correlation of volume changes with Cobb angle changes before and after the surgery. Materials and Methods: Eighteen non-smoker patients with idiopathic scoliosis were included in this descriptive observational study. Cobb angle, lung volume and flow were measured before and after the surgery. To assess height and weight changes during the follow-up period, we used the percent relative to normal (percent predicted) instead of absolute volumes. Results: Eighteen of 30 selected patients were included. The mean follow-up period was 34.5â� 19.6 months. Dynamic volume changes of lung were: VC= -13.4 SD=8.6 (p<0.005); FVC=-9.22 SD=14 (p<0.001); FEV1=9.8 SD=15 (p<0.001). There was a weak correlation between the mean value of dynamic volume changes and the mean changes in Cobb angle after the surgery. There was a weak correlation between Cobb angle and dynamic volume of lung before the surgery. Conclusion: In this study there was a significant decrement of dynamic lung volumes after corrective surgery for thoracic curve scoliosis. © 2008 NRITLD, National Research Institute of Tuberculosis and Lung Disease, Iran

HBMO Based Output Feedback Damping Controller for STATCOM

The aim of this paper is to investigate a novel approach for output feedback damping controller design of the static synchronous compensator (STATCOM) in order to enhance the damping of power system low frequency oscillations (LFO). The design of output feedback controller is considered as an optimization problem according to the time domain-based objective function solved by a honey bee mating optimization (HBMO) algorithm that has a strong ability to find the most optimistic results. To validate the accuracy of results a comparison with genetic algorithm (GA) has been made. The effectiveness of the proposed controller are tested and demonstrated through eigenvalue analysis and nonlinear time-domain simulation studies over a wide range of loading conditions. The simulation study shows that the designed controller by HBMO performs better than GA in finding the solution.U ovome radu istražene su metode za sintezu regulatora prigušenja za statički sinkroni kompenzator (STATCOM) u svrhu povećanja prigušenja nisko frekvencijskih oscilacija u energetskim sustavima. Sinteza regulatora je razmatrana kao optimizacijski problem u vremenskoj domeni koji je riješen pomoću HBM algoritma optimizacije (eng. Honey bee mating) koji ima svojstvo pronalaska najoptimističnijeg rezultata. U svrhu provjere rezultata napravljena je usporedba s rješenjem koje daje genetski algoritam. Efikasnost predloženog regulatora testirana je uz pomoć analize svojstvenih vrijednosti i nelinearnih simulacija u vremenskoj domeni za različite uvjete. Simulacijski rezultati pokazuju da se korištenjem regulatora s HBM optimizacijom postižu bolji rezultati nego korištenjem genetskog algoritma

Prevalence of and factors associated with frailty and disability in older adults from China, Ghana, India, Mexico, Russia and South Africa

BackgroundThe severe burden imposed by frailty and disability in old age is a major challenge for healthcare systems in low- and middle-income countries alike. The current study aimed to provide estimates of the prevalence of frailty and disability in older adult populations and to examine their relationship with socioeconomic factors in six countries.MethodsFocusing on adults aged 50+ years, a frailty index was constructed as the proportion of deficits in 40 variables, and disability was assessed using the World Health Organization Disability Assessment Schedule (WHODAS 2.0), as part of the Study on global AGEing and adult health (SAGE) Wave 1 in China, Ghana, India, Mexico, Russia and South Africa.ResultsThis study included a total of 34,123 respondents. China had the lowest percentages of older adults with frailty (13.1%) and with disability (69.6%), whereas India had the highest percentages (55.5% and 93.3%, respectively). Both frailty and disability increased with age for all countries, and were more frequent in women, although the sex gap varied across countries. Lower levels of both frailty and disability were observed at higher levels of education and wealth. Both education and income were protective factors for frailty and disability in China, India and Russia, whereas only income was protective in Mexico, and only education in South Africa.ConclusionsAge-related frailty and disability are increasing concerns for older adult populations in low- and middle-income countries. The results indicate that lower levels of frailty and disability can be achieved for older people, and the study highlights the need for targeted preventive approaches and support programs