COVID-19 numbers and models: Misleading us, or leading us out of misery?

The majority of the world's population is affected to some degree or another by the COVID-19 pandemic and measures to curb its spread. Newspapers and social media bombard us with numbers, graphs, and predictions every day, but what do these numbers really tell us

On the lowest eigenvalue of Laplace operators with mixed boundary conditions

In this paper we consider a Robin-type Laplace operator on bounded domains. We study the dependence of its lowest eigenvalue on the boundary conditions and its asymptotic behavior in shrinking and expanding domains. For convex domains we establish two-sided estimates on the lowest eigenvalues in terms of the inradius and of the boundary conditions

Simulation-based surgical education for glaucoma versus conventional training alone: the GLAucoma Simulated Surgery (GLASS) trial. A multicentre, multicountry, randomised controlled, investigator-masked educational intervention efficacy trial in Kenya, South Africa, Tanzania, Uganda and Zimbabwe.

BACKGROUND/AIM: Glaucoma accounts for 8% of global blindness and surgery remains an important treatment. We aimed to determine the impact of adding simulation-based surgical education for glaucoma. METHODS: We designed a randomised controlled, parallel-group trial. Those assessing outcomes were masked to group assignment. Fifty-one trainee ophthalmologists from six university training institutions in sub-Saharan Africa were enrolled by inclusion criteria of having performed no surgical trabeculectomies and were randomised. Those randomised to the control group received no placebo intervention, but received the training intervention after the initial 12-month follow-up period. The intervention was an intense simulation-based surgical training course over 1 week. The primary outcome measure was overall simulation surgical competency at 3 months. RESULTS: Twenty-five were assigned to the intervention group and 26 to the control group, with 2 dropouts from the intervention group. Forty-nine were included in the final intention-to-treat analysis. Surgical competence at baseline was comparable between the arms. This increased to 30.4 (76.1%) and 9.8 (24.4%) for the intervention and the control group, respectively, 3 months after the training intervention for the intervention group, a difference of 20.6 points (95% CI 18.3 to 22.9, p<0.001). At 1 year, the mean surgical competency score of the intervention arm participants was 28.6 (71.5%), compared with 11.6 (29.0%) for the control (difference 17.0, 95% CI 14.8 to 19.4, p<0.001). CONCLUSION: These results support the pursuit of financial, advocacy and research investments to establish simulation surgery training units and courses including instruction, feedback, deliberate practice and reflection with outcome measurement to enable trainee glaucoma surgeons to engage in intense simulation training for glaucoma surgery. TRIAL REGISTRATION NUMBER: PACTR201803002159198

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

Selective laser trabeculoplasty versus 0.5% timolol eye drops for the treatment of glaucoma in Tanzania: a randomised controlled trial

BACKGROUND: Glaucoma is a major cause of sight-loss worldwide, with the highest regional prevalence and incidence reported from Africa. The most common low-cost treatment used in this region to control glaucoma is long-term timolol eye drops. However, side effects, low adherence, limited availability, and high long-term costs are a challenge. Selective laser trabeculoplasty (SLT) is a short outpatient procedure to lower eye pressure but was not formally compared with standard treatment in Africa. We tested the hypothesis that SLT is superior to timolol 0·5% eye drops for the treatment of open-angle glaucoma. METHODOLOGY: A randomised, controlled, parallel group, single-masked clinical trial was conducted at KCMC Eye Department, Moshi, Tanzania. Participants (aged ≥18 years) had open-angle glaucoma, intraocular pressure (IOP) >21mmHg and neither previous glaucoma surgery nor asthma. They were randomly allocated to receive timolol 0.5% eye drops twice daily or SLT. The primary outcome was the proportion of success after one year defined as an IOP ≤18mmHg for eyes with advanced glaucoma (disc damage likelihood scale (DDLS) 8-10) and IOP ≤21mmHg for moderate glaucoma (DDLS 5-7). Re-explaining the application of eye drops or a repeat SLT was permitted once. Further outcomes included safety, acceptance, vision-related quality of life (VRQoL) using the WHO/PBD VF20 questionnaire, preservation of visual acuity, and cost. Results were analysed by intention to treat using logistic regression; generalised estimating equations were used to adjust for the correlation between eyes. RESULTS: 201 participants (382 eligible eyes) were enrolled; 100 people (191 eyes) were randomly assigned to timolol and 101 (191 eyes) to SLT. At baseline, mean IOP was 26.7mmHg (SD 6.9mmHg), 162 eyes had moderate glaucoma and 220 eyes advanced glaucoma. DDLS yielded an area under the receiver operating characteristics curve (AROC) of 0.90 (95% CI 0.87-0.93), compared to AROC for vertical CDR of 0.88 (95% CI 0.85-0.91), p=0.048, for identifying severe/end-stage disease. After one year, 339 eyes were analysed (89%). Treatment was successful in 55/176 eyes (31.3%) in the timolol arm (39 eyes without repeat counselling) and in 99/163 eyes (60.7%) in the SLT arm (66 eyes without repeat SLT); odds ratio 3.37 (95% CI 1.96-5.80, p1/2 of the laser spot size as predictors, and only IOP ≥25mmHg for the model after repeat SLT. CONCLUSIONS: SLT was superior to timolol for managing open-angle glaucoma in this East African setting. It has potential to transform the management of glaucoma in Africa, even where the prevalence of advanced stages of this blinding disease is high