Person: Bonnin Arias, Cristina Natalia
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First Name
Cristina Natalia
Last Name
Bonnin Arias
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Optometría y Visión
Area
Optica
Identifiers
8 results
Search Results
Now showing 1 - 8 of 8
Item Valoración del espesor del ápex corneal con topógrafo de Scheimpflug: Repetibilidad de las medidas.(Gaceta de Optometría y óptica oftálmica, 2012) Bonnin Arias, Cristina Natalia; Chamorro Gutiérrez, Eva; Lobato Rincón, Luis Lucio; Sánchez Ramos, CeliaIntroducción. La medida del espesor corneal (EC) es un parámetro a tener en cuenta en la práctica óptico-oftalmológica, debido a su relación con otras variables de gran interés clínico. Existen distintos instrumentos, con diferentes bases físicas, que valoran el EC. Propósito. El objeto de este estudio fue evaluar la repetibilidad de las medidas de espesor corneal en el ápex, en personas de diferentes edades, obtenidas mediante un topógrafo de Scheimpflug. Material y métodos. La muestra estaba constituida por un total de 120 medidas del espesor del ápex corneal, 20 registros por cada una de las 6 personas seleccionadas, una por cada década de edad. Las medidas se realizaron con el topógrafo Pentacam. Resultados. Se calculó el coeficiente de variación de Pearson (CV) obteniendo, según las décadas, 1º=1,23; 2º=0,75; 3º=1,23; 4º=1.01; 5º=0.71; 6º=1.01. Conclusión. El instrumento también ha demostrado una adecuada repetibilidad para uso clínico de las medidas.Item Riesgos personales producidos por LEDs utilizados en dispositivos de uso cotidiano(Seguridad y medio ambiente (Fundación MAPFRE), 2012) Chamorro Gutiérrez, Eva; Bonnin Arias, Cristina Natalia; Lobato Rincón, Luis Lucio; Navarro Valls, Juan José; Ramirez Mercado, Guillermo; Navarro Blanco, Carolina; Sánchez Ramos, CeliaEl uso de fuentes de iluminación LED (diodos emisores de luz) está creciendo de manera exponencial tanto en el campo de la iluminación ambiente como en dispositivos de uso personal y doméstico como smartphones, pantallas de ordenador, electrodomésticos, etc. Sin embargo, el principal problema que plantean los LEDs que emiten luz blanca radica en su alto contenido de radiaciones de la banda del azul, que son dañinas para el sistema visual. En este proyecto se ha diseñado un dispositivo de iluminación formado por diodos LED de diferentes características espectrales para comprobar si producen daño en la retina, sobre todo en células del epitelio pigmentario. Los experimentos han demostrado que la exposición a la luz aumenta el porcentaje de muerte celular inducida por la luz para todas las fuentes de luz LED, especialmente en las células expuestas a luz azul y blanca, en las que se produjo un aumento de la muerte celular respecto al control del 92% y 94% respectivamente. El estudio concluye que la exposición a altas intensidades de luz LED durante ciclos de luz/oscuridad produce daños en las células de la retina.Item Effects of Light‐emitting Diode Radiations on Human Retinal Pigment Epithelial Cells in vitro(Photochemistry and Photobiology, 2012) Chamorro, Eva; Muñoz de Luna, Javier; Bonnin Arias, Cristina Natalia; Pérez Carrasco, María Jesús; Vázquez Molini, Daniel; Sánchez Ramos, CeliaHuman visual system is exposed to high levels of natural and artificial lights of different spectra and intensities along lifetime. Light-emitting diodes (LEDs) are the basic lighting components in screens of PCs, phones and TV sets; hence it is so important to know the implications of LED radiations on the human visual system. The aim of this study was to investigate the effect of LEDs radiations on human retinal pigment epithelial cells (HRPEpiC). They were exposed to three light-darkness (12 h/12 h) cycles, using blue-468 nm, green-525 nm, red-616 nm and white light. Cellular viability of HRPEpiC was evaluated by labeling all nuclei with DAPI; Production of reactive oxygen species (ROS) was determined by H2DCFDA staining; mitochondrial membrane potential was quantified by TMRM staining; DNA damage was determined by H2AX histone activation, and apoptosis was evaluated by caspases-3,-7 activation. It is shown that LED radiations decrease 75-99% cellular viability, and increase 66-89% cellular apoptosis. They also increase ROS production and DNA damage. Fluorescence intensity of apoptosis was 3.7% in nonirradiated cells and 88.8%, 86.1%, 83.9% and 65.5% in cells exposed to white, blue, green or red light, respectively. This study indicates three light-darkness (12 h/12 h) cycles of exposure to LED lighting affect in vitro HRPEpiC.Item Light regulates the expression of the BDNF/TrkB system in the adult Zebrafish retina(Microscopy Research and Technique, 2012) Guerrera, María Cristina; García Calavia, Marta; Chamorro Gutiérrez, Eva; Montalbano, Giuseppe; López Velasco, Salvador; López Muñiz, Alfonso Joaquín; Germanà, Antonino; Vega Álvarez, José Antonio; Sánchez Ramos, Celia; Bonnin Arias, Cristina NataliaThe retina of the adult zebrafish express brain‐derived neurotrophic factor (BDNF) and its signaling receptor TrkB. This functional system is involved in the biology of the vertebrate retina and its expression is regulated by light. This study was designed to investigate the effects of cyclic (12 h light/12 h darkness) or continuous (24 h) exposure during 10 days to white light, white‐blue light, and blue light, as well as of darkness, on the expression of BDNF and TrkB in the retina. BDNF and TrkB were assessed in the retina of adult zebrafish using quantitative real‐time polymerase chain reaction and immunohistochemistry. Exposure to white, white‐blue, and blue light causes a decrease of BDNF mRNA and of BDNF immunostaining, independently of the pattern of light exposition. Conversely, in the same experimental conditions, the expression of TrkB mRNA was upregulated and TrkB immunostaining increased. Exposition to darkness diminished BDNF and TrkB mRNAs, and abolished the immunostaining for BDNF but not modified that for TrkB. These results demonstrate the regulation of BDNF and TrkB by light in the retina of adult zebrafish and might contribute to explain some aspects of the complex pathophysiology of light‐induced retinopathies.Item Expression of TRPV4 in the zebrafish retina during development(Microscopy Research and Technique, 2012) Guerrera, María Cristina; García Calavia, Marta; Laurà, Rosaria; Germanà, Antonino; Vega Álvarez, José Antonio; Sánchez Ramos, Celia; Bonnin Arias, Cristina NataliaThe transient receptor potential (TRP) channels are involved in sensing mechanical/physical stimuli such as temperature, light, pressure, as well as chemical stimuli. Some TRP channels are present in the vertebrate retina, and the occurrence of the multifunctional channel TRP vanilloid 4 (TRPV4) has been reported in adult zebrafish. Here, we investigate the expression and distribution of TRPV4 in the retina of zebrafish during development using polymerase chain reaction (PCR), Western blot, and immunohistochemistry from 3 days post fertilization (dpf) until 100 dpf. TRPV4 was detected at the mRNA and protein levels in the eye of zebrafish at all ages sampled. Immunohistochemistry revealed the presence of TRPV4 in a population of the retinal cells identified as amacrine cells on the basis of their morphology and localization within the retina, as well as the co‐localization of TRPV4 with calretinin. TRPV4 was first (3 dpf) found in the soma of cells localized in the inner nuclear and ganglion cell layers, and thereafter (10 dpf) also in the inner plexiform layer. The adult pattern of TRPV4 expression was achieved by 40 dpf the expression being restricted to the soma of some cells in the inner nuclear layer and ganglion cell layers. These data demonstrate the occurrence and developmental changes in the expression and localization of TRPV4 in the retina of zebrafish, and suggest a role of TRPV4 in the visual processing.Item Wetability and deposits accomulation on anterior surface of blue light-filtering contact lens.(2012) Chamorro Gutiérrez, E.; Bonnin Arias, Cristina Natalia; Ramirez Mercado, G.; Urbano Rodríguez, R.; Ríos Santos, R.; Sánchez Ramos, CeliaPurpose: To evaluate wetability and deposits accumulation on anterior surface of blue light-fi ltering contact lens after a cleaning process with Multi-purpose Solution Cleaning, Hydrogen Peroxide solution and Lubricant Drops. Methods: A self-controlled trial was carried out in 41 contact lens users who were wearing blue light-fi ltering contact lens (Profi lcon A 52%WC) for 30 minutes per test. Wetability and deposits accumulation on anterior surface were evaluated according to the International Organization for Standardization ISO11980 guidelines. Four conditions were set: a)usual contact lens, b)blue light-fi ltering contact lens after cleaning process with Multi-purpose Solution Cleaning, c)after Hydrogen Peroxide solution disinfection and d) after Lubricant Drops instillation. Results: Statistically signifi cant diff erences were not observed within the parameters evaluated among the diff erent cleaning solutions proposed. For a,b,c and d conditions, the percentage of lens that showed very insignifi cant deposits accumulation(visible after drying tear fi lm) were 25%,34%,20% and 27%, respectively and the percentage of lens that showed not signifi cant deposits (deposits easily eliminated) were 3%,2%,7% and 8%, respectively. Regarding wetability, minor wetability problems were showed and these ones were solved by the blinking in 18%, 29%, 18% and 18% of the cases, respectively, whereas the areas that remained dry on the contact lenses were 4%,0%,5% and 2% of the cases. Conclusion: wetability and deposits accumulation on anterior surface of blue light filtering contact lenses is similar for the diff erent cleaning treatment and equivalent to the non blue light-fi ltering contact lens.Item Changes in contrast sensitivity perception due to protector screens for welding tasks : conventional protective optical filter vs novel protective optical filter of selective absorbance(2012) Bonnin Arias, Cristina Natalia; Aguirre Vilacoro, V.; Chamorro Gutiérrez, E.; Lobato Rincón, Luis Lucio; Langa Moraga, Antonio; Navarro Valls, J.J.; Sánchez Ramos, CeliaPurpose: To evaluate diff erences in contrast sensitivity perception in central visual field using protective optic fi lters for welding tasks. Two interposed filters are compared: a conventional protective optical fi lter and a new protective optical fi lter with selective absorption designed by University Complutense of Madrid (UCM). Methods: 36 people of working-age were included in a cross-sectional prospective observational study. Contrast sensitivity threshold in central visual fi eld was evaluated using FDT Perimeter, C-20 procedure (Humphrey systems, USA). ! ree conditions were set: a) without optical fi lters; b) with an interposition of conventional protective optical fi lter for welding (shade 2.5) and c) with an interposition of a novel protective optical fi lter of selective absorbance that fully blocks the short wavelength light and minimally attenuates the remaining bands of the visible spectrum. Results: Contrast sensitivity in all visual fi eld areas evaluated diminished 91-98% with the conventional protective optical fi lters. UCM optical fi lters provoked a low-level decrease in contrast sensitivity (9-19%). Mean contrast sensitivity thresholds were 29.5±5dB, 25.5±4dB, 1.8±2dB in conditions a, b and c respectively Conclusion: Conventional optical fi lters resulted in drastically diminished contrast sensitivity. UCM optical fi lter minimally diminish the visual function, allowing a suitable visibility and also maintaining an appropriate level of protection against phototoxic damage.Item Acid-Sensing ion channels 2 and 4 (Asic 2 Saic 4) are regulated by light in the zebrafish retina(2012) Sánchez Ramos, Celia; Germaná, A.; Bonnin Arias, Cristina Natalia; Chamorro Gutiérrez, E.; Navarro Valls, J.J.; García Ortega, M.; Pérez Carrasco, María Jesús; Vega, J.A.Purpose: Acid-sensing ion channels (ASICs) are H+- gated cation channels that monitor deviations from the physiological values of extracellular pH. ASIC genes in zebrafish (zASICs) are expressed in the central nervous system and the retina. pH variations in the retina are thought to be involved in the fine-tunning of visual perception and in the adaptation of the retinal responses to different light-induced retinal degeneration. This study examines the effects of continuous light or darkness exposure in the mRNA levels and cell distribution of ASIC2 and ASIC4 in the retina of adult zebrafish.