Normal tension glaucoma: A dynamic optical coherence tomography angiography study

PurposeVascular dysregulation seems to play a role in the pathogenesis of glaucoma, in particular normal tension glaucoma (NTG). The development of optical coherence tomography angiography (OCTA) enabled the measurement of the retinal microvasculature non-invasively and with high repeatability. Nonetheless, only a few studies transformed OCTA into a dynamic examination employing a sympathomimetic stimulus. The goal of this study was to use this dynamic OCTA exam (1) to differentiate healthy individuals from glaucoma patients and (2) to distinguish glaucoma subcategories, NTG and high-tension primary open angle glaucoma (POAG).MethodsRetinal vessel density (VD) in NTG patients (n = 16), POAG patients (n = 12), and healthy controls (n = 14) was compared before and during a hand grip test with a hydraulic dynamometer.ResultsAt baseline, mean peripapillary VD was lower in POAG and NTG (42.6 and 48.5%) compared to healthy controls (58.1%; p < 0.001) and higher in NTG compared to POAG (p = 0.024) when corrected for mean arterial pressure (MAP). Peripapillary and macular (superficial and deep) VD differences were found for gender, age, and baseline MAP. No change in VD occurred (pre-/post-stimulus) in any of the groups.ConclusionRetinal VD loss in glaucoma patients was confirmed and the necessity to correct for gender, age and especially MAP was established. Although replication in a larger population is necessary, OCTA might not be the most suitable method to dynamically evaluate the retinal microvasculature

Retinal OCT speckle as a biomarker for glaucoma diagnosis and staging

This paper presents a novel image analysis strategy that increases the potential of macular Optical Coherence Tomography (OCT) by using speckle features as biomarkers in different stages of glaucoma. A large pool of features (480) were computed for a subset of macular OCT volumes of the Leuven eye study cohort. The dataset contained 258 subjects that were divided into four groups based on their glaucoma severity: Healthy (56), Mild (94), Moderate (48), and Severe (60). The OCT speckle features were categorized as statistical properties, statistical distributions, contrast, spatial gray-level dependence matrices, and frequency domain features. The averaged thicknesses of ten retinal layers were also collected. Kruskal-Wallis H test and multivariable regression models were used to infer the most significant features related to glaucoma severity classification and to the correlation with visual field mean deviation. Four features were selected as being the most relevant: the ganglion cell layer (GCL) and the inner plexiform layer (IPL) thicknesses, and two OCT speckle features, the data skewness computed on the retinal nerve fiber layer (RNFL) and the scale parameter (a) of the generalized gamma distribution fitted to the GCL data. Based on a significance level of 0.05, the regression models revealed that RNFL skewness exhibited the highest significance among the features considered for glaucoma severity staging (p-values of 8.6×10-6 for the logistic model and 2.8×10-7 for the linear model). Furthermore, it demonstrated a strong negative correlation with the visual field mean deviation (ρ=-0.64). The post hoc analysis revealed that, when distinguishing healthy controls from glaucoma subjects, GCL thickness is the most relevant feature (p-value of 8.7×10-5). Conversely, when comparing the Mild versus Moderate stages of glaucoma, RNFL skewness emerged as the only feature exhibiting statistical significance (p-value = 0.001). This work shows that macular OCT speckle contains information that is currently not used in clinical practice, and not only complements structural measurements (thickness) but also has a potential for glaucoma staging

Microvascular damage assessed by optical coherence tomography angiography for glaucoma diagnosis: a systematic review of the most discriminative regions

A growing number of studies have reported a link between vascular damage and glaucoma based on optical coherence tomography angiography (OCTA) imaging. This multitude of studies focused on different regions of interest (ROIs) which offers the possibility to draw conclusions on the most discriminative locations to diagnose glaucoma. The objective of this work was to review and analyse the discriminative capacity of vascular density, retrieved from different ROIs, on differentiating healthy subjects from glaucoma patients. PubMed was used to perform a systematic review on the analysis of glaucomatous vascular damage using OCTA. All studies up to 21 April 2019 were considered. The ROIs were analysed by region (macula, optic disc and peripapillary region), layer (superficial and deep capillary plexus, avascular, whole retina, choriocapillaris and choroid) and sector (according to the Garway–Heath map). The area under receiver operator characteristic curve (AUROC) and the statistical difference (p-value) were used to report the importance of each ROI for diagnosing glaucoma. From 96 screened studies, 43 were eligible for this review. Overall, the peripapillary region showed to be the most discriminative region with the highest mean AUROC (0.80 ± 0.09). An improvement of the AUROC from this region is observed when a sectorial analysis is performed, with the highest AUROCs obtained at the inferior and superior sectors of the superficial capillary plexus in the peripapillary region (0.86 ± 0.03 and 0.87 ± 0.10, respectively). The presented work shows that glaucomatous vascular damage can be assessed using OCTA, and its added value as a complementary feature for glaucoma diagnosis depends on the region of interest. A sectorial analysis of the superficial layer at the peripapillary region is preferable for assessing glaucomatous vascular damage

OCTA multilayer and multisector peripapillary microvascular modeling for diagnosing and staging of glaucoma

Purpose: To develop and assess an automatic procedure for classifying and staging glaucomatous vascular damage based on optical coherence tomography angiography (OCTA) imaging. Methods: OCTA scans (Zeiss Cirrus 5000 HD-OCT) from a random eye of 39 healthy subjects and 82 glaucoma patients were used to develop a new classification algorithm based on multilayer and multisector information. The averaged circumpapillary retinal nerve fiber layer (RNFL) thickness was also collected. Three models, support vector machine (SVM), random forest (RF), and gradient boosting (xGB), were developed and optimized for classifying between healthy and glaucoma patients, primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG), and glaucoma severity groups. Results: All the models, the SVM (area under the receiver operating characteristic [AUROC] 0.89 ± 0.06), the RF (AUROC 0.86 ± 0.06), and the xGB (AUROC 0.85 ± 0.07), with 26, 22, and 29 vascular features obtained after feature selection, respectively, presented a similar performance to the RNFL thickness (AUROC 0.85± 0.06) in classifying healthy and glaucoma patients. The superficial vascular plexus was the most informative layer with the infero temporal sector as the most discriminative region of interest. No significant differentiation was obtained in discriminating the POAG from the NTG group. The xGB model, after feature selection, presented the best performance in classifying the severity groups (AUROC 0.76± 0.06), outperforming the RNFL (AUROC 0.67± 0.06). Conclusions: OCTA multilayer and multisector information has similar performance to RNFL for glaucoma diagnosis, but it has an added value for glaucoma severity classification, showing promising results for staging glaucoma progression. Translational Relevance: OCTA, in its current stage, has the potential to be used in clinical practice as a complementary imaging technique in glaucoma management

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

O Impacto da Pandemia COVID-19 no Internato de Formação Específica de Oftalmologia em Portugal

Introduction: The purpose of this study was to provide objective and real-life data concerning the impact of the COVID-19 pandemic on ophthalmology residency training in Portugal. Material and Methods: Descriptive survey-based study applied to current Portuguese ophthalmology residents (n = 80 eligible). Results: Seventy-five residents participated (94% response rate). All except one (99%) admitted a change in their routine clinical practice during the pandemic, and most (89%) continued to be engaged in ophthalmology department duties. Twenty-five percent were deployed to COVID-19 units, which was combined with ophthalmological activities in about half of them (47%). A significant proportion of participants stated that they were enrolled in the following ophthalmological activities: emergency/inpatient care (87%), outpatient visits (73%; general 70% vs subspecialty 29%), and surgical procedures (64%). Twenty-five percent did not assist in any outpatient visits and 36% did not participate in any surgical procedures. On a scale from 1 (no impact) to 5 (maximum impact), most participants classified their perceived negative impact of the pandemic on the training program as 3 (24%), 4 (40%), or 5 (27%). Participants highly agreed with the extension of the residency program (80%) in order to to make up for training disruption. Discussion: Most trainees provided ophthalmological care during the pandemic. However, those clinical activities were essentially related to general and emergency care. Surgical experience was significantly curtailed. As such, strategies are needed to guarantee a high-quality learning process. Further studies are required to develop an international perspective on how ophthalmology training programs have been affected so that educational organizations can make recommendations regarding standardized adjustments to training programs. Conclusion: The COVID-19 pandemic has significantly impacted the training of ophthalmology residents nationwide.Introdução: Este estudo teve como objetivo avaliar o impacto da pandemia COVID-19 no internato de Formação Específica de Oftalmologia em Portugal. Material e Métodos: Estudo descritivo dos resultados obtidos de um questionário aplicado a todos os internos de Formação Específica de Oftalmologia em Portugal (n = 80). Resultados: Setenta e cinco internos participaram no estudo (taxa de resposta de 94%). Excetuando um caso, todos (99%) admitiram alteração da sua prática clínica durante a pandemia, e a maioria (89%) manteve atividades clínicas no seu serviço de Oftalmologia. Vinte e cinco por cento foram integrados em unidades COVID-19, e metade desses inquiridos (47%) desempenharam concomitantemente atividades no âmbito da oftalmologia. Uma percentagem significativa dos inquiridos referiu estar envolvido nas seguintes atividades clínicas oftalmológicas: serviço de Urgência/consultas internas (87%), consultas externas (73%: geral 70% vs subespecialidade 29%), e cirurgias (64%). Vinte e cinco por cento não participaram em consultas externas, e 36% em procedimentos cirúrgicos. Numa escala de 1 (sem impacto) a 5 (máximo impacto), a maioria dos inquiridos classificou o impacto percecionado da pandemia no internato de Formação Específica de Oftalmologia em 3 (34%), 4 (40%) e 5 (27%). Oitenta porcento dos inquiridos enumerou a extensão do período do internato de Formação Específica como uma medida a adotar para minimizar o impacto negativo da pandemia. Discussão: A maioria dos internos mantiveram-se a desempenhar atividades clínicas no seu serviço de Oftalmologia, principalmente no âmbito da oftalmologia geral e de urgência. O desempenho de atividade cirúrgica foi largamente afetado. São necessárias estratégias adaptativas para garantir a continuação adequada da formação dos internos. Futuros estudos noutros contextos geográficos permitirão perceber de que forma os programas de formação em oftalmologia estão a ser afetados ao nível internacional, para que as organizações educacionais possam elaborar recomendações. Conclusão: A pandemia COVID-19 teve um impacto significativo no internato de Formação Específica de Oftalmologia em Portugalinfo:eu-repo/semantics/publishedVersio

Porque Deve o Financiamento para a Recuperação Pós-Pandemia SARS-CoV-2 Ser Usado para Criar um Progra-ma de Médicos-Cientistas?

info:eu-repo/semantics/publishedVersio