15 research outputs found

    Turismo sustentável e desenvolvimento local: projecto da Mata de Sesimbra

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    A presente dissertação investiga o campo do Turismo Sustentável/Ecológico, caracterizando diferentes conceitos; enquadra a evolução da problemática ambiental; estuda a relação entre o Turismo e o Ambiente, os seus impactos (económicos, sócio-culturais e ambientais) e respectiva medição e controlo; e destaca a importância de um bom planeamento e gestão turísticos. Numa segunda fase, relativa à área dos Projectos Turísticos Sustentáveis, e de modo a consolidar esta dissertação toma-se o caso de estudo do Projecto da Mata de Sesimbra – o primeiro projecto integrado de construção, ecoturismo sustentável e conservação da natureza a nível nacional, levado a cabo pela imobiliária Pelicano em parceria com a ONG World Wildlife Fund e a BioRegional – à semelhança do bem sucedido Projecto BedZed no Reino Unido (uma eco-cidade que permite aos seus residentes terem um estilo de vida amigo do ambiente, com o nível de conforto e qualidade de vida de hoje em dia). Então, são apresentadas as entidades envolvidas e projectos semelhantes, antes da análise do plano de pormenor e plano de gestão ambiental do projecto em estudo. Esta investigação pretende demonstrar o mérito que projectos como este têm no desenvolvimento local, os seus impactos positivos e negativos, e indica os instrumentos que os norteiam e os obstáculos que se lhes colocam, como linhas de orientação para projectos semelhantes. Para o efeito, tendo por base a documentação relativa ao mesmo, o projecto é analisado na vertente territorial (desenvolvimento do projecto e planos de ordenamento do território seguidos), sócio-cultural (relação entre a população local e o empreendimento turístico) e económica (importância do turismo, em especial de projectos inovadores deste género, na actividade local), tendo em conta a problemática ambiental transversal às três vertentes, ao tentar responder às perguntas de partida: Como criar valor local com o Projecto da Mata de Sesimbra? Qual a gestão do projecto, barreiras e apoios inerentes ao desenvolvimento turístico sustentável em Sesimbra?This dissertation investigates the field of Sustainable/Ecological Tourism, characterizes different concepts, within the evolution of the environmental problematic; studies the relation between Tourism and the Environment, its impacts (economic, socialcultural and environmental), evaluation and control; and highligths the importance of an efficient tourism planning and management. In the second part, concerning Sustainable Touristic Projects, to consolidate this work the case-study “Mata de Sesimbra” Project, in Portugal, is presented and analysed – the first national project that combines building constrution, sustainable ecotourism and nature conservation, developed by the real estate company Pelicano in partnership with the ONG World Wildlife Fund and BioRegional – following the example of the well succeeded BedZed Project in the United Kingdom (an eco-village where its residents can have a ecofriendly style of life, with the comfort and quality of life of nowadays). Therefore, the entities involved and similar projects are presented, before the analysis of the project’s detail plan and environmental management plan. This investigation aim consists in demonstrating the merit of such projects in the local development, its positive and negative impacts, indicating the instruments that guide them and the obstacles in its implementation, as a guide line for similar iniciatives. Based on the documentation related to it, the project is analysed by three approaches: territorial (project development and land-use plans followed), social-cultural (the relationship between local community and the touristic endeavour) and economic (tourism importance to the local economy, specially of this kind of innovative projects), taking into account the environmental issue cross-cutting these approaches, trying to answer the starting point questions: How to create local value with the “Mata de Sesimbra” Project? Which are the project management, barriers and supports inherent to sustainable touristic development in Sesimbra

    Corneal Biomechanics in Ectatic Diseases: Refractive Surgery Implications.

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    BACKGROUND: Ectasia development occurs due to a chronic corneal biomechanical decompensation or weakness, resulting in stromal thinning and corneal protrusion. This leads to corneal steepening, increase in astigmatism, and irregularity. In corneal refractive surgery, the detection of mild forms of ectasia pre-operatively is essential to avoid post-operative progressive ectasia, which also depends on the impact of the procedure on the cornea. METHOD: The advent of 3D tomography is proven as a significant advancement to further characterize corneal shape beyond front surface topography, which is still relevant. While screening tests for ectasia had been limited to corneal shape (geometry) assessment, clinical biomechanical assessment has been possible since the introduction of the Ocular Response Analyzer (Reichert Ophthalmic Instruments, Buffalo, USA) in 2005 and the Corvis ST (Oculus Optikgerate GmbH, Wetzlar, Germany) in 2010. Direct clinical biomechanical evaluation is recognized as paramount, especially in detection of mild ectatic cases and characterization of the susceptibility for ectasia progression for any cornea. CONCLUSIONS: The purpose of this review is to describe the current state of clinical evaluation of corneal biomechanics, focusing on the most recent advances of commercially available instruments and also on future developments, such as Brillouin microscopy.(undefined)info:eu-repo/semantics/publishedVersio

    Ocular Biomechanics and Glaucoma

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    Biomechanics is a branch of biophysics that deals with mechanics applied to biology. Corneal biomechanics have an important role in managing patients with glaucoma. While evidence suggests that patients with thin and stiffer corneas have a higher risk of developing glaucoma, it also influences the accurate measurement of intraocular pressure. We reviewed the pertinent literature to help increase our understanding of the biomechanics of the cornea and other ocular structures and how they can help optimize clinical and surgical treatments, taking into consideration individual variabilities, improve the diagnosis of suspected patients, and help monitor the response to treatment

    Bowman's topography for improved detection of early ectasia

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    The aim of this study was to evaluate whether OCT topography of the Bowman's layer and artificial intelligence (AI) can result in better diagnosis of forme fruste (FFKC) and clinical keratoconus (KC). Normal (n = 221), FFKC (n = 72) and KC (n = 116) corneas were included. Some of the FFKC and KC patients had the fellow eye (VAE-NT) with normal topography (n = 30). The Scheimpflug and OCT scans of the cornea were analyzed. The curvature and surface aberrations (ray tracing) of the anterior corneal surface [air-epithelium (A-E) interface in OCT] and epithelium-Bowman's layer (E-B) interface (in OCT only) were calculated. Four random forest models were constructed: (1) Scheimpflug only; (2) OCT A-E only; (3) OCT E-B only; (4) OCT A-E and E-B combined. For normal eyes, both Scheimpflug and OCT (A-E and E-B combined) performed equally in identifying these eyes (P = .23). However, OCT A-E and E-B showed that most VAE-NT eyes were topographically similar to normal eyes and did not warrant a separate classification based on topography alone. For identifying FFKC eyes, OCT A-E and E-B combined performed significantly better than Scheimpflug (P = .006). For KC eyes, both Scheimpflug and OCT performed equally (P = 1.0). Thus, OCT Topography of Bowman's layer significantly improved the detection of FFKC eyes

    Investigation of How Corneal Densitometry Artefacts Affect the Imaging of Normal and Keratoconic Corneas

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    Purpose: To investigate corneal densitometry artefacts found in Pentacam Scheimpflug scans and their potential effect on assessing keratoconic (KC) corneas compared to normal (N) corneas. Methods: The current study utilises Pentacam data of 458 N eyes, aged 35.6 ± 15.8 (range 10–87), referred to as the “N group”, and 314 KC eyes, aged 31.6 ± 10.8 (range 10–72), referred to as the “KC group”, where densitometry data were extracted and analysed via a custom-built MATLAB code. Radial summations of the densitometry were calculated at diameters ranging from 0.5 mm to 5.0 mm. The minimum normalised radial summation of densitometry (NRSD) value and angle were determined at each diameter and then linked. KC cone locations and areas of pathology were determined, and a comparison between N and KC groups was carried out both within the averaged area of pathology and over the corneal surface. Results: Joining minimum NRSD trajectory points marked a clear distortion line pointing to the nasal-superior direction at 65° from the nasal meridian. The findings were found to be independent of eye laterality or ocular condition. Consistency was detected in the right and left eyes among both the N and KC groups. The location of the KC cone centre and the area of pathology were determined, and the densitometry output was compared both within the area of pathology and over the whole cornea. When the average densitometry was compared between N and KC eyes within the KC area of pathology, the N group recorded a 16.37 ± 3.15 normalised grey-scale unit (NGSU), and the KC group recorded 17.74 ± 3.4 NGSU (p = 0.0001). However, when the whole cornea was considered, the N group recorded 16.71 ± 5.5 NGSU, and the KC group recorded 15.72 ± 3.98 NGSU (p = 0.0467). A weak correlation was found between the Bad D index and NGSU when the whole measured cornea was considered (R = −0.01); however, a better correlation was recorded within the KC area of pathology (R = 0.21). Conclusions: Nasal-superior artefacts are observed in the densitometry Pentacam maps, and analysis shows no significant differences in their appearance between N or KC corneas. When analysing KC corneas, it was found that the cone positions are mostly on the temporal-inferior side of the cornea, opposite to the densitometry artefact NRSD trajectory. The analysis suggests that the corneal densitometry artefacts do not interfere with the KC area of pathology as it reaches its extreme in the opposite direction; therefore, weighting the densitometry map to increase the contribution of the inferior-temporal cornea and decreasing that of the superior-nasal area would improve the classification or identification of KC if densitometry is to be used as a KC metric.</jats:p

    Enhanced Diagnostics for Corneal Ectatic Diseases: The Whats, the Whys, and the Hows

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    There are different fundamental diagnostic strategies for patients with ectatic corneal diseases (ECDs): screening, confirmation of the diagnosis, classification of the type of ECD, severity staging, prognostic assessment, and clinical follow-up. The conscious application of such strategies enables individualized treatments. The need for improved diagnostics of ECD is related to the advent of therapeutic refractive procedures that are considered prior to keratoplasty. Among such less invasive procedures, we include corneal crosslinking, customized ablations, and intracorneal ring segment implantation. Besides the paradigm shift in managing patients with ECD, enhancing the sensitivity to detect very mild forms of disease, and characterizing the inherent susceptibility for ectasia progression, became relevant for identifying patients at higher risk for progressive iatrogenic ectasia after laser vision correction (LVC). Moreover, the hypothesis that mild keratoconus is a risk factor for delivering a baby with Down’s syndrome potentially augments the relevance of the diagnostics of ECD. Multimodal refractive imaging involves different technologies, including Placido-disk corneal topography, Scheimpflug 3-D tomography, segmental or layered tomography with layered epithelial thickness using OCT (optical coherence tomography), and digital very high-frequency ultrasound (VHF-US), and ocular wavefront. Corneal biomechanical assessments and genetic and molecular biology tests have translated to clinical measurements. Artificial intelligence allows for the integration of a plethora of clinical data and has proven its relevance in facilitating clinical decisions, allowing personalized or individualized treatments

    Dynamic corneal deformation response and integrated corneal tomography

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    Measuring corneal biomechanical properties is still challenging. There are several clinical applications for biomechanical measurements, including the detection of mild or early forms of ectatic corneal diseases. This article reviews clinical applications for biomechanical measurements provided by the Corvis ST dynamic non contact tonometer.info:eu-repo/semantics/publishedVersio

    Integration of Scheimpflug-Based corneal tomography and biomechanical assessments for enhancing ectasia detection

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    PURPOSE: To present the Tomographic and Biomechanical Index (TBI), which combines Scheimpflugbased corneal tomography and biomechanics for enhancing ectasia detection. METHODS: Patients from different continents were retrospectively studied. The normal group included 1 eye randomly selected from 480 patients with normal corneas and the keratoconus group included 1 eye randomly selected from 204 patients with keratoconus. There were two groups: 72 ectatic eyes with no surgery from 94 patients with very asymmetric ectasia (VAE-E group) and the fellow eyes of these patients with normal topography (VAE-NT group). Pentacam HR and Corvis ST (Oculus Optikgerate GmbH, Wetzlar, Germany) parameters were analyzed and combined using different artificial intelligence methods. The accuracies for detecting ectasia of the Belin/Ambresio Deviation (BAD-D) and Corvis Biomechanical Index (CBI) were compared to the TBI, considering the areas under receiver operating characteristic curves (AUROCs). RESULTS: The random forest method with leave-oneout cross-validation (RF/LOOCV) provided the best artificial intelligence model. The AUROC for detecting ectasia (keratoconus, VAE-E, and VAE-NT groups) of the TBI was 0.996, which was statistically higher (DeLong et al., P < .001) than the BAD-D (0.956) and CBI (0.936). The TBI cut-off value of 0.79 provided 100% sensitivity for detecting clinical ectasia (keratoconus and VAE-E groups) with 100% specificity. The AUROCs for the TBI, BAD-D, and CBI were 0.985, 0.839, and 0.822 in the VAE-NT group (DeLong et al., P <.001). An optimized TBI cut-off value of 0.29 provided 90.4% sensitivity with 96% specificity in the VAE-NT group. CONCLUSIONS: The TBI generated by the RF/LOOCV provided greater accuracy for detecting ectasia than other techniques. The TBI was sensitive for detecting subclinical (fruste) ectasia among eyes with normal topography in very asymmetric patients. The TBI may also confirm unilateral ectasia, potentially characterizing the inherent ectasia susceptibility of the cornea, which should be the subject of future studies.Dr. Ambrosio, Dr. P. Vinciguerra, and Dr. Roberts are consultants for, Dr. Buhren has received lecture fees from, and Dr. Elsheikh has received research funding from Oculus Optikgerate GmbH (Wetzlar, Germany). The remaining authors have no financial or proprietary interest in the materials presented herein.info:eu-repo/semantics/publishedVersio
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