36 research outputs found
Recommended from our members
Severity of Visual Field Loss at First Presentation to Glaucoma Clinics in England and Tanzania
Purpose: To compare severity of visual field (VF) loss at first presentation in glaucoma clinics in England and Tanzania.
Methods: Large archives of VF records from automated perimetry were used to retrospectively examine vision loss at first presentation in glaucoma clinics in Tanzania (N = 1,502) and England (N = 9,264). Mean deviation (MD) of the worse eye at the first hospital visit was used as an estimate of detectable VF loss severity.
Results: In Tanzania, 44.7% {CI95%: 42.2, 47.2} of patients presented with severe VF loss (< −20 dB), versus 4.6% {4.1, 5.0} in England. If we consider late presentation to also include cases of advanced loss (-12.01 dB to -20 dB), then the proportion of patients presenting late was 58.1% {55.6, 60.6} and 14.0% {13.3, 14.7}, respectively. The proportion of late presentations was greater in Tanzania at all ages, but the difference was particularly pronounced among working-age adults, with 50.3% {46.9, 53.7} of 18–65-year-olds presenting with advanced or severe VF loss, versus 10.2% {9.3, 11.3} in England. In both countries, men were more likely to present late than women.
Conclusions: Late presentation of glaucoma is a problem in England, and an even greater challenge in Tanzania. Possible solutions are discussed, including increased community eye-care, and a more proactive approach to case finding through the use of disruptive new technologies, such as low-cost, portable diagnostic aids
Feeding mice with diets containing mercury-contaminated fish flesh from French Guiana: a model for the mercurial intoxication of the Wayana Amerindians
International audienc
Grand Challenges in global eye health: a global prioritisation process using Delphi method
Background
We undertook a Grand Challenges in Global Eye Health prioritisation exercise to identify the key issues that must be addressed to improve eye health in the context of an ageing population, to eliminate persistent inequities in health-care access, and to mitigate widespread resource limitations.
Methods
Drawing on methods used in previous Grand Challenges studies, we used a multi-step recruitment strategy to assemble a diverse panel of individuals from a range of disciplines relevant to global eye health from all regions globally to participate in a three-round, online, Delphi-like, prioritisation process to nominate and rank challenges in global eye health. Through this process, we developed both global and regional priority lists.
Findings
Between Sept 1 and Dec 12, 2019, 470 individuals complete round 1 of the process, of whom 336 completed all three rounds (round 2 between Feb 26 and March 18, 2020, and round 3 between April 2 and April 25, 2020) 156 (46%) of 336 were women, 180 (54%) were men. The proportion of participants who worked in each region ranged from 104 (31%) in sub-Saharan Africa to 21 (6%) in central Europe, eastern Europe, and in central Asia. Of 85 unique challenges identified after round 1, 16 challenges were prioritised at the global level; six focused on detection and treatment of conditions (cataract, refractive error, glaucoma, diabetic retinopathy, services for children and screening for early detection), two focused on addressing shortages in human resource capacity, five on other health service and policy factors (including strengthening policies, integration, health information systems, and budget allocation), and three on improving access to care and promoting equity.
Interpretation
This list of Grand Challenges serves as a starting point for immediate action by funders to guide investment in research and innovation in eye health. It challenges researchers, clinicians, and policy makers to build collaborations to address specific challenge
Explicit exponential decay bounds in quasilinear parabolic problems
This paper deals with classical solutions of some initial boundary value problems involving the quasilinear parabolic equation where are given functions. In the case of one space variable, i.e. when , we establish a maximum principle for the auxiliary function where a is an arbitrary nonnegative parameter. In some cases this maximum principle may be used to derive explicit exponential decay bounds for and . Some extensions in space dimensions are indicated. This work may be considered as a continuation of previous works by Payne and Philippin (Mathematical Models and Methods in Applied Sciences, 5 (1995), 95–110; Decay bounds in quasilinear parabolic problems, In: Nonlinear Problems in Applied Mathematics, Ed. by T.S. Angell, L. Pamela, Cook, R.E., SIAM, 1997).</p
Decay estimates for solutions of a class of parabolic problems arising in filtration through porous media
Applications of the maximum principle to a variety of problems involving elliptic and parabolic equations
Continous dependance result for a class of nonlinear heat equations in a cylindrical region
In this paper, we derive bounds for the solutions of a quasilinear heat equation in a finite cylindrical
region if the far end and the lateral surface are held at zero temperature, and a nonzero temperature is
applied at the near end. Some continuous dependence inequalities are also obtained. We also investigate
the case in which a given heat flux is prescribed at the near end, instead of a given temperature