Person:
López Alonso, José Manuel

First Name

José Manuel

Last Name

López Alonso

URI

https://hdl.handle.net/20.500.14352/79879

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Óptica y Optometría

Department

Óptica

Area

Optica

Identifiers

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Search Results

Now showing 1 - 10 of 18

Development of an algorithm to track blinks from a face video
(Proceedings. International Online Symposium of Young Optometrists (SIYO 2022), 2022) Marrakchi, Youssef; López Alonso, José Manuel; Garzón Jiménez, Nuria; González Pérez, Mariano; Universidad de Valencia
The VI International Symposium of Young Optometrists (SIYO 2022) took place from November 14-28 2022 in its usual online format. This conference aims to create a space where young optometry students and optometry practitioners are the protagonists. This book of proceedings contains the abstracts of the different contributions to the conference. Its contents are organizing in two sections: invited and sponsored oral communication and workshops, and free communication. This last section is divided in oral communications and poster communications, comprising the conference’s different thematic areas. The Organizing Committee thanks all the young and senior researchers that have contributed their work to the conference, the members of the Scientific Commettee for their careful reviews of the works and the different enterprises and accademic or offical entities that have sponsored this event.
Zemax OpticStudio toolbox as a method for visual quality analysis in multifocal contact lenses
(Proceedings. International Online Symposium of Young Optometrists (SIYO 2022), 2022) López Raso, Alicia; López Alonso, José Manuel; Burgos Martínez , Mercedes; Ruiz Alcocer, Javier; Goodenoough ,Neil; Universidad de Valencia
The VI International Symposium of Young Optometrists (SIYO 2022) took place from November 14-28 2022 in its usual online format. This conference aims to create a space where young optometry students and optometry practitioners are the protagonists. This book of proceedings contains the abstracts of the different contributions to the conference. Its contents are organizing in two sections: invited and sponsored oral communication and workshops, and free communication. This last section is divided in oral communications and poster communications, comprising the conference’s different thematic areas. The Organizing Committee thanks all the young and senior researchers that have contributed their work to the conference, the members of the Scientific Commettee for their careful reviews of the works and the different enterprises and accademic or offical entities that have sponsored this event.El Simposio Internacional de Jóvenes Optometristas pretende crear un espacio donde participen conjuntamente jóvenes estudiantes y profesionales de la optometría para facilitar la divulgación de sus investigaciones, así como el contacto y la colaboración. Este libro recopila los resúmenes de las diferentes contribuciones que se presentaron en su cuarta edición, que se celebró del 14 al 28 de noviembre de 2022 en su habitual formato en línea. Se organiza en dos secciones que comprenden las diferentes áreas temáticas de las conferencias, con el objetivo de mejorar la atención en el ámbito de la óptica y la optometría mediante la integración de la investigación en la práctica sanitaria.
Contact lens fitting through assessment of tear film affectation with different designs by means of thermal camera
(Frontiers in Optics / Laser Science, 2020) Durán Prieto, Elena; López Alonso, José Manuel
The study of contact lenses fitting of different designs through the impact on the tear through infrared images of the eye has been carried out. Multifocal lens design behaves as well as traditional ones.
Comparison of soft toric contact lenses with and without prism ballast stabilization system
(2022) Durán Prieto, Elena; González Pascual , María del Mar; Burgos Martínez, Mercedes; Carballo Álvarez, Jesús; López Alonso, José Manuel
The VI International Symposium of Young Optometrists (SIYO 2022) took place from November 14-28 2022 in its usual online format. This conference aims to create a space where young optometry students and optometry practitioners are the protagonists. This book of proceedings contains the abstracts of the different contributions to the conference. Its contents are organizing in two sections: invited and sponsored oral communication and workshops, and free communication. This last section is divided in oral communications and poster communications, comprising the conference’s different thematic areas. The Organizing Committee thanks all the young and senior researchers that have contributed their work to the conference, the members of the Scientific Commettee for their careful reviews of the works and the different enterprises and accademic or offical entities that have sponsored this event.
Retinal vascular tortuosity in glaucoma and diabetic retinopathy: correlation with vessel diameters
(PROCEEDINGS International Online Symposium of Young Optometrists SIYO 2022, 2022) López Alonso, José Manuel; Igalla El-Youssfi, Asmae; Universidad de Valencia
The VI International Symposium of Young Optometrists (SIYO 2022) took place from November 14-28 2022 in its usual online format. This conference aims to create a space where young optometry students and optometry practitioners are the protagonists. This book of proceedings contains the abstracts of the different contributions to the conference. Its contents are organizing in two sections: invited and sponsored oral communication and workshops, and free communication. This last section is divided in oral communications and poster communications, comprising the conference’s different thematic areas. The Organizing Committee thanks all the young and senior researchers that have contributed their work to the conference, the members of the Scientific Commettee for their careful reviews of the works and the different enterprises and accademic or offical entities that have sponsored this event.
La influencia del equipo de adquisición de imágenes retinianas y tratamiento en la medida de la dimensión fractal
(2021) Igalla El-Youssfi, Asmae; López Alonso, José Manuel
Objetivo: La medida de la dimensión fractal de la imagen retiniana se ha mostrado como útil en la valoración de varias patologías. Nuestro objetivo es determinar la influencia del instrumento y la forma de adquisición de las imágenes retinianas en las medidas de la dimensión fractal local (LFD) y la conectada (Dlc) en imágenes de retinas sanas y patológicas con un método de segmentación morfológica y otro de umbralización (Threshold). Para ello se utilizan imágenes retinianas sanas procedentes de dos bancos de datos diferentes: clínica e internet (31 y 15 imágenes respectivamente), cada uno tomado con un retinógrafo distinto. Métodos: Se realiza una segmentación previa de la imagen para quedarse con la imagen binarizada del canal verde de la imagen RGB de la retina y el tratamiento de imagen con la segmentación morfológica, que utiliza un filtro ‘‘morfológico’’ para quedarse solo con los vasos. Medianteel Plugin “Fraclac” del programa ImageJ, se realiza el análisis fractal de las imágenes retinianas binarizadas y, en el programa Matlab se representan las curvas de las distribuciones de probabilidad de la DF de cada grupo estudiado, y se comparan entre sí. Resultados: El método de segmentación morfológica es más estable entre bancos de imágenes diferentes. Esto quiere decir que las distribuciones de probabilidad de las dimensiones fractales son cualitativamente más semejantes que las derivadas con el método Threshold para los dos bancos de datos. Discusión y Conclusión: La comparación de imágenes de la dimensión fractal de retina son más fiables con el método de segmentación morfológica que atiende sobre todo a patologías de la vasculatura. El método Threshold aporta también información valiosa sobre la estructura patológica de la capa retiniana, porque incluye todas las alteraciones que pueden afectar la retina, aunque es dependiente del instrumento de medida, lo cual limita su uso.
Distancia KullBack Leibler entre distribuciones de dimensión fractal: cuantificación de la relevancia patológica de las imágenes retinianas
(2021) Igalla El-Youssfi, Asmae; López Alonso, José Manuel
Se ha desarrollado un método de cuantificación del grado de patología de imagen de fondo de ojo mediante el análisis de la dimensión fractal conectada de la vasculatura retiniana. El método se basa en la cuantificación de la diferencia entre la distribución de probabilidad de esta dimensión para retinas sanas y patológicas, usando la divergencia de Kullback Leibler entre ellas. Los resultados sobre imágenes de retinopatía diabética y glaucoma muestran una alta fiabilidad respecto a la detección de patología por expertos humanos, teniendo en cuenta, además, la variabilidad propia entre retinas sanas y permitiendo cuantificar el grado de patología.
Optimization and validation of biomedical retinal images for fractal vascular measurement
(Frontiers in Optics / Laser Science, 2020) Igalla El-Youssfi, Asmae; López Alonso, José Manuel
The influence of the contrast and morphological filtering in the measurement of the local and connected fractal dimension of retinal images has been studied, being greater in morphological filter and fractal connected dimension.
Comparison and evaluation of local and connected fractal dimension to analyze the retinal images
(Frontiers in Optics / Laser Science, 2020) Igalla El-Youssfi, Asmae; López Alonso, José Manuel
The analysis of the fractal dimension (FD) of the retinas using the methods for measuring local (LFD) and connected (Dlc) DF in images of healthy retinas establishes a similar behavior with slightly differences.
Multifractal analysis of embryonic eye structures from female mice with dietary folic acid deficiency. Part I: Fractal dimension, lacunarity, divergence, and multifractal spectrum
(Chaos, Solitons and Fractals, 2020) Sijilmassi, Ouafa; López Alonso, José Manuel; Río Sevilla, Aurora Del; Barrio Asensio, María Del Carmen
The purpose of this study was to investigate effects of low maternal folic acid (FA) status on many eye structures in embryonic mice using multifractal analysis, a method for describing complex structural patterns. To do this, we used the FracLac plugin for ImageJ to analyse binary digital images of cornea, lens, retina, and vitreous after immunohistochemical analysis using anti-collagen IV or anti-laminin-1 antibodies. The box-counting and gliding box methods were used to generate metrics including the fractal dimension, lacunarity, divergence, and multifractal spectrum distance metrics for each ocular structure. Results were analysed using bootstrap resampling techniques and the Kruskal-Wallis significance test. For all structures and staining methods studied, differences between embryos from control vs FA-deficient females were detectable in lacunarity plots and multifractal spectra, and statistically significant in cornea, lens, retina and vitreous. Multifractal analysis detected even slight differences in tissue textures presumably attributable to altered expression of extracellular matrix molecules.