Antón Pelayo, Javier (2013). La correspondència epistolar de la família Burguès (1750-1850)

Antón Pelayo, Javier (2013)La correspondència epistolar de la família Burguès (1750-1850)Bellaterra: Universitat Autònoma de Barcelona, 334 p.ISBN 978-84-490-4212-6 (paper) / 978-84-490-4391-8 (digital)Antón Pelayo, Javier (2013)La correspondència epistolar de la família Burguès (1750-1850)Bellaterra: Universitat Autònoma de Barcelona, 334 p.ISBN 978-84-490-4212-6 (paper) / 978-84-490-4391-8 (digital)Antón Pelayo, Javier (2013)La correspondència epistolar de la família Burguès (1750-1850)Bellaterra: Universitat Autònoma de Barcelona, 334 p.ISBN 978-84-490-4212-6 (paper) / 978-84-490-4391-8 (digital

The variability of corneal and anterior segment parameters in keratoconus

Purpose: To analyse, describe and test diverse corneal and anterior segment parameters in normal and keratoconic eyes to better understand the geometry of the keratoconic cornea. Method: 44 eyes from 44 keratoconic patients and 44 eyes from 44 healthy patients were included in the study. The Pentacam System was used for the analysis of the anterior segment parameters. New ad-hoc parameters were defined by measuring the distances on the Scheimpflug image at the horizontal diameter, with chamber depth now comprising of two distinctive distances: corneal sagittal depth and the distance from the endpoint of this segment to the anterior surface of the lens (DL). Results: Statistically significant differences (p<0.05) between normal and keratoconic eyes were found in all of the analysed corneal parameters. Anterior chamber depth presented statistical differences between normal and keratoconic eyes (3.06 ± 0.43 mm versus 3.34 ± 0.45 mm, respectively; p = 0.004). This difference was found to originate in an increase of the DL distance (0.40 ± 0.33 mm in normal eyes against 0.61 ± 0.45 mm in keratoconic eyes; p = 0.014), rather than in the changes in corneal sagittal depth. Conclusion: These findings indicate that keratoconus results in central and peripheral corneal manifestations, as well as changes in the shape of the scleral limbus. The DL parameter was useful in describing the forward elongation and advance of the scleral tissue in keratoconic eyes. This finding may help in the monitoring of disease progression and contact lens design and fitting.Preprin

Real-Time Non-Intrusive Assessment of Viewing Distance During Computer Use

Purpose: To develop and test the sensitivity of an ultrasound-based sensor to assess the viewing distance of visual display terminals operators in real-time conditions. Methods: A modified ultrasound sensor was attached to a computer display to assess viewing distance in real time. Sensor functionality was tested on a sample of 20 healthy participants while they conducted four 10-minute randomly presented typical computer tasks (a match-three puzzle game, a video documentary, a task requiring participants to complete a series of sentences, and a predefined internet search). Results: The ultrasound sensor offered good measurement repeatability. Game, text completion, and web search tasks were conducted at shorter viewing distances (54.4 cm [95% CI 51.3-57.5 cm], 54.5 cm [95% CI 51.1-58.0 cm], and 54.5 cm [95% CI 51.4-57.7 cm], respectively) than the video task (62.3 cm [95% CI 58.9-65.7 cm]). Statistically significant differences were found between the video task and the other three tasks (all p < 0.05). Range of viewing distances (from 22 to 27 cm) was similar for all tasks (F = 0.996; p = 0.413). Conclusions: Real-time assessment of the viewing distance of computer users with a non-intrusive ultrasonic device disclosed a task-dependent pattern. (C) 2016 American Academy of OptometryPostprint (author's final draft

Comparative analysis of peripheral corneal geometry in health and Keratoconus

OBJECTIVES:: To describe and compare corneal peripheral angles in normal and keratoconic eyes, to gain a better understanding of the topography of the periphery of the cornea in keratoconus and assist practitioners in the selection and fitting of large diameter contact lenses. METHODS:: Eighty-eight eyes were included in the study, divided into three groups: healthy (A0, 28 eyes), keratoconus at stage I according to the Amsler-Krumeich classification (AI, 33 eyes) and keratoconus at stages II to IV (AII, 27 eyes). The Pentacam Scheimpflug system was used to manually measure the corneal peripheral angles corresponding to a chord length range between 8.6 and 12.6 mm at 8 different peripheral locations. RESULTS:: The peripheral angle was influenced by ocular condition and by the peripheral location, with no interaction effect between both factors. Statistically significant differences were found in mean corneal peripheral angles between groups A0 (30.84°±2.33°) and AI (31.63°±2.02°) (P=0.001) and between A0 and AII (31.37°±2.11°) (P=0.030). The differences between AI and AII were not significant. In all eyes, the largest and smallest peripheral angles were found at the temporal inferior and temporal superior locations, respectively, with a mean difference between largest and smallest of 3.37°±1.42° in healthy eyes and 2.96°±1.54° in keratoconus (AI+AII). CONCLUSION:: Clinically insignificant differences were found in peripheral angles between keratoconus and healthy eyes, giving support to the use of large diameter, intralimbal contact lenses with peripheral designs, and resting on the same corneal region, as those fitted on normal corneas.Preprin

Anterior chamber parameters in early and advanced keratoconus. A meridian by meridian analysis

Purpose: To explore anterior segment changes with keratoconus onset and progression to determine whether structural changes are predominantly corneal, limbal or both. To investigate these changes in different corneal meridians. Method: Eighty-four eyes with keratoconus and 49 healthy eyes were included in the study. Eyes with keratoconus were divided in two groups according to the Amsler-Krumeich classification: stage I and stages II-IV. Scheimpflug images at three different meridians were used to evaluate the following parameters: anterior chamber depth from the endothelium (ACD_end) and corneal thickness (CT) (software provided), anterior chamber depth (ACD) and sagittal depth (SAGT) from the epithelium, and distance from the end point of SAGT to the anterior surface of the lens (DL) (measured manually), and [ACD – CT] and [SAGT – CT] (calculated). Changes in these parameters with ocular condition and meridian were analysed. Results: Statistically significant larger values were found of ACD (p=0.012) and DL (p=0.016) with keratoconus onset and progression, with no differences in SAGT values. Besides, [ACD – CT] and [SAGT – CT] were significantly larger in keratoconus eyes (p<0.001 and p=0.003, respectively). Significant differences (all p<0.001) were found in SAGT, [SAGT – CT] and DL among meridians. Changes in these parameters with keratoconus onset and progression were similar in all meridians. Conclusion: Considering the results from the three meridians under investigation, it may be concluded that keratoconus onset has an impact on the anterior segment as a whole and not only on corneal structures. The DL distance is a useful parameter to describe limbal changes in keratoconus.Postprint (author's final draft

A New Slit Lamp–Based Technique for Anterior Chamber Angle Estimation

Purpose: To design and test a new noninvasive method for anterior chamber angle (ACA) estimation based on the slit lamp that is accessible to all eye-care professionals. Methods: A new technique (slit lamp anterior chamber estimation [SLACE]) that aims to overcome some of the limitations of the van Herick procedure was designed. The technique, which only requires a slit lamp, was applied to estimate the ACA of 50 participants (100 eyes) using two different slit lamp models, and results were compared with gonioscopy as the clinical standard. Results: The Spearman nonparametric correlation between ACA values as determined by gonioscopy and SLACE were 0.81 (p < 0.001) and 0.79 (p < 0.001) for each slit lamp. Sensitivity values of 100 and 87.5% and specificity values of 75 and 81.2%, depending on the slit lamp used, were obtained for the SLACE technique as compared with gonioscopy (Spaeth classification). Conclusions: The SLACE technique, when compared with gonioscopy, displayed good accuracy in the detection of narrow angles, and it may be useful for eye-care clinicians without access to expensive alternative equipment or those who cannot perform gonioscopy because of legal constraints regarding the use of diagnostic drugs

Aplicació d’eines TIC a la millora de les competències clíniques en l’àmbit de l’òptica i l’optometria: “OPTOstream”

Actualment, l’estudiantat de la Facultat d’Òptica i Optometria de les assignatures clíniques (Grau i Màster) participen de forma activa en l’atenció de pacient reals, sota la supervisió del professorat. Els casos atesos durant les sessions pràctiques es plantegen i discuteixen en les sessions de seminari amb els docents i la resta del grup. Malgrat el valor docent d’aquesta metodologia, l’estudiant no tenia la possibilitat de comprovar la seva actuació durant l’atenció d’un cas real, a partir de les observacions del docent. Aquesta situació dificulta un aprofitament òptim de l’experiència d’aprenentatge per part de l’estudiant. La incorporació de solucions tècniques contrastades en l’àmbit de la formació, com és el cas de l’enregistrament i visionat posterior o en temps real de casos, permeten a l’estudiant participar més activament en el seu procés d’aprenentatge i contribueixen a fer més efectiva l’adquisició de determinats coneixements i competències bàsiques per al desenvolupament de la seva carrera professional i investigadora. El projecte “OPTOstream” ha permès desenvolupar una metodologia pròpia basada en l’elaboració i anàlisi posterior de casos enregistrats en vídeo o bé la projecció en temps real de les actuacions clíniques al nou auditori de la Facultat.Peer Reviewe

Adaptation to multifocal and monovision contact lens correction

Purpose. To compare visual performance with the Biofinity multifocal (MF) contact lens with monovision (MV) with the Biofinity single-vision contact lens. Methods. A crossover study of 20 presbyopic patients was conducted. Patients were randomized first into either an MF or an MV lens for 15 days for each modality, with a washout period between each lens type. Measurements included monocular and binocular high- and low-contrast logarithm of the minimum angle of resolution visual acuity (VA) at distance and near visions, binocular distance contrast sensitivity function, and near stereoacuity. Results. At 15 days, patients lost fewer than two letters (half a line of VA) of binocular distance and near VA, with the MF and MV lens under high- and low-contrast conditions (P 9 0.05 for both comparisons). No statistically significant differences were seen in binocular VA at near or distance with either lens. However, the monocular distance VA improved significantly in the nondominant eye, with the MF lens by one line over the 15-day period under high-contrast (P = 0.023) and lowcontrast (P = 0.035) conditions; this effect was not seen with the MV lens. Contrast sensitivity function was within the normal limits with both lenses. The stereoacuity was significantly (P G 0.01) better with MF than with MV. Conclusions. Multifocal contact lens correction provided satisfactory levels of VA comparable with MV without compromising stereoacuity in this crossover study. The near vision significantly improved in the dominant eye, and the distance vision improved in the nondominant eye from 1 to 15 days with the MF lens, suggesting that patients adapted to the multifocality overtime, whereas this was not true for MV. (Optom Vis Sci 2013;90:228Y235)The authors declare that they do not have any proprietary or financial interest in any of the materials mentioned in this article. This study has been funded by projects PTDC/SAU-BEB/098392/2008 and PTDC/SAU-BEB/098391/2008 funded by the Portuguese Fundacao para a Ciencia e Tecnologia through the European Social Fund. This study has been partly supported by an unrestricted grant from CooperVision

Strategies for early keratoconus diagnosis: a narrative review of evaluating affordable and effective detection techniques

Keratoconus is a progressive corneal disorder that can lead to irreversible visual impairment if not detected early. Despite its high prevalence, early diagnosis is often delayed, especially in low-to-middle-income countries due to limited awareness and restricted access to advanced diagnostic tools such as corneal topography, tomography, optical coherence tomography, and corneal biomechanical assessments. These technologies are essential for identifying early-stage keratoconus, yet their high cost limits accessibility in resource-limited settings. While cost and portability are important for accessibility, the sensitivity and specificity of diagnostic tools must be considered as primary metrics to ensure accurate and effective detection of early keratoconus. This review examines both traditional and advanced diagnostic techniques, including the use of machine learning and artificial intelligence, to enhance early diagnosis. Artificial intelligence-based approaches show significant potential for transforming keratoconus diagnosis by improving the accuracy and sensitivity of early diagnosis, especially when combined with imaging devices. Notable innovations include tools such as SmartKC, a smartphone-based machine-learning application, mobile corneal topography through the null-screen test, and the Smartphone-based Keratograph, providing affordable and portable solutions. Additionally, contrast sensitivity testing demonstrates potential for keratoconus detection, although a precise platform for routine clinical use has yet to be established. The review emphasizes the need for increased awareness among clinicians, particularly in underserved regions, and advocates for the development of accessible, low-cost diagnostic tools. Further research is needed to validate the effectiveness of these emerging technologies in detecting early keratoconus.Peer ReviewedObjectius de Desenvolupament Sostenible::3 - Salut i BenestarPostprint (published version

Ressenyes

Obra ressenyada: Javier ANTÓN PELAYO, La correspondència epistolar de la família Burguès (1750-1850). Bellaterra: Universitat Autònoma de Barcelona, 2013