Person:
Bonnin Arias, Cristina Natalia

First Name

Cristina Natalia

Last Name

Bonnin Arias

URI

https://hdl.handle.net/20.500.14352/79903

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Óptica y Optometría

Department

Optometría y Visión

Area

Optica

Identifiers

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Now showing 1 - 10 of 31

Visión Limitada: Variación de la percepción visual por la utilización de Equipos de Protección Individual para intervenciones NRBQ
(Seguridad y Medio Ambiente (Fundación Mapfre), 2010) Bonnin Arias, Cristina Natalia; Navarro Valls, Juan José; Lobato Rincón, Luis Lucio; Ramirez Mercado, Guillermo; Sánchez Ramos, Celia
Los equipos de protección individual (EPI) preparados para entornos de riesgos NRBQ (entornos de riesgo Nuclear-Radiológico-Biológico-Químico), que aíslan y protegen a los intervinientes en estas acciones, presentan importantes limitaciones para la percepción visual. En este artículo, se estudio por primera vez cuál es el grado de afectación de las capacidades visuales de los usuarios cuando actúan protegidos por un EPI de este tipo. Estos EPIs, por sus condiciones de aislantes y protectores, presentan importantes limitaciones físicas que dan lugar a una percepción visual deficiente del entorno: resolución espacial, sensibilidad al contraste y la percepción del color por la superposición de superficies transparentes sin calidad óptica.
Role of Metalloproteases in Retinal Degeneration Induced by Violet and Blue Light
(Advances in Experimental Medicine and Biology, 2009) Sánchez Ramos, Celia; Vega, J.A.; Del Valle, M.E.; Álvarez Fernández-Balbuena, Antonio; Bonnin Arias, Cristina Natalia; Benítez Del Castillo Sánchez, José Manuel; Anderson, RE (Anderson, RE) ; LaVail, MM (LaVail, MM) ; Hollyfield, JG (Hollyfield, JG) ; Mandal, MNA (Mandal, MNA)
Introduction: An essential role for metalloproteases (MMPs) has been described in blood vessel neoformation and the removal of cell debris. MMPs also play a key role in degenerative processes and in tumors. The participation of these enzymes in light-induced phototoxic processes is supported by both experimental and clinical data. Given that patients with age-related macular degeneration often show deposits, or drusen, these deposits could be the consequence of deficient MMP production by the pigment epithelium. Objective: To gain insight into the regulation of metalloproteases in the pathogenia of retinal degeneration induced by light. Materials and methods: We examined the eyes of experimental rabbits exposed for 2 years to circadian cycles of white light, blue light and white light lacking short wavelengths. For the trial the animals had been implanted with a transparent intraocular lens (IOL) and a yellow AcrySof((R)) IOL, one in each eye. After sacrificing the animals, the retinal layer was dissected from the eye and processed for gene expression analyses in which we examined the behavior of MMP-2, MMP-3 and MMP-9. Results: MMP-2 expression was unaffected by the light received and type of IOL. However, animals exposed to white light devoid of short wavelengths or those fitted with a yellow IOL showed 2.9- and 3.6-fold increases in MMP-3 expression, respectively compared to controls. MMP-9 expression levels were also 3.1 times higher following exposure to blue light and 4.6 times higher following exposure to white light lacking short wavelengths or 4.2 times higher in eyes implanted with a yellow IOL. Conclusion: Exposure to long periods of light irrespective of its characteristics leads to the increased expression of some MMPs. This alteration could indicate damage to the extracellular matrix and have detrimental effects on the retina.
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.
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, Celia
El 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.
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, Celia
Introducción. 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.
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 Natalia
The 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.
Variation of mesopic and photopic spatial resolution in drivers older than 65 years old.
(2009) Sánchez Ramos, Celia; Bonnin Arias, Cristina Natalia; García García, R.; Vinas Pena, M.; Chamorro Gutiérrez, E.; Gómez Tortuero, E.
In the last century, the proportion of people over the age of 65 years has tripled (Haegerstrom-Portnoy, 1999). According to the US census 2000, persons over 65 years of age comprised 12.4% of the inhabitants of the United States (Schwager, 1999). The spanish National Institute of Statistics estimated this proportion at 16.8% of the population of Spain in 2009, representing a growth rate far higher than shown by other age groups (INE, 2009). Besides this increase, the number of elderly people who continue to drive is set to show a spectacular rise after 2010, due to the incorporation of the "baby-boom" generation and the considerably greater number of women drivers. Added to this social changes and the improved health of the elderly subject are raising the mean age of drivers (Hakkinen, 1984). Spherical and astigmatic defects worsen with age, negatively affecting visual acuity and sensitivity to contrast and glare. Ageing is also associated with diminised myopia, increased hyperopic and tendency towards inverse astigmatism (Adams, 1988). In addition, the retina often undergoes macular degeneration (Morgan, 1986). The physiological alterations of ageing also lead to changes in our sensitivity to light. Enhanced light scattering in the eye gives rise to glare, a decreased pupil diameter with the consequent reduced retinal illumination and to a general decline in visual perception (Van Den Ber, 1986). The present investigation was designed to evaluate the refractive error in vehicle drivers over the age of 65 years and to determine the possible effects of improving their habitual optical correction on visual acuity.
Optical filter quality effect on pupil size in night driving.
(2009) Vinas Pena, M.; Sánchez Ramos, Celia; Chamorro Gutiérrez, E.; Bonnin Arias, Cristina Natalia
Luminance conditions during driving vary tremendously, with, in some cases, abrupt differences between areas of intense and poor illumination, depending on the daytime, the weather, vehicle headlights and the environmental illumination, among others. This affects to the driver´s visual system, which is able to adapt itself to these different luminances by varyting its pupil size. There is little doubt that the most important and best-studied afferent visual signal that drives the pupil is generated by changing the ambient illumination. The accepted clinical view of the pupil response to light is that the ambient light level determines largely the steady state size of the pupil and that rapid increments in light flux on the retina cause a brisk constriction of the pupil, that is often described as the dynamic pupil light relfex response. The pupil response to changes in ambient illumination is best served by neural mechanisms that respond to overall light flux changes, cover a large dynamic range and exhibit large spatial summation. Pupillary response to light measures the integrity of neuronal pathways goberning pupil size. The oculomotor nerve is the efferent link and the optic nerve is the afferent link. The mechanisms controlling the pupillary constriction and dilation have been explained by Barbur (2004) and Lowenfeld (1993). Briefly, a large pupil diameter reduces distortion due to light diffraction and dispersion and allow more light to reach the retina. Conversely, by limiting the entry of light rays, a small pupil increases the depth of focus and reduces chromatic and spherical aberrations.
Protección de riesgos laborales de trabajadores que utilizan soplete autógeno.
(Seguridad y Medio Ambiente (Fundación Mapfre), 2011) Bonnin Arias, Cristina Natalia; Navarro Valls, Juan José; Lobato Rincón, Luis Lucio; Ramirez Mercado, Guillermo; Chamorro Gutiérrez, Eva; Sánchez Ramos, Celia
En el mundo laboral existen profesiones de especial riesgo en las que se realizan procesos de soldadura, que pueden deteriorar la retina. Los gremios más afectados son los trabajadores de empresas automovilísticas,siderometalúrgicas, instaladores de aire acondicionado y calefacción. Aunque la normativa vigente obliga a la empresa a proporcionar a sus empleados los elementos protectores frente a la radiación nociva emitida por el soplete, no los suelen utilizar debido al excesivo oscurecimiento de las lentes, ya que la falta de visión origina accidentes laborales por quemaduras o errores. Por ello, prefieren soldar sin protección, lo que les hace propensos a sufrir graves daños retinianos irreversibles, incluso escotomas absolutos de importancia relevante. Este trabajo propone nuevos filtros protectores que permitan, a la vez, la fotoprotección retiniana y la visibilidad del campo de trabajo. Para ello se ha analizado el espectro de emisión del soplete y se han diseñado los filtros necesarios para absorber las bandas nocivas emitidas por éste, dando lugar a un prototipo. Posteriormente se han evaluado varios aspectos de la percepción visual con la interposición del nuevo filtro propuesto por la Universidad Complutense de Madrid (UCM) y de otro filtro convencional para soldadura. Los resultados obtenidos muestran que el filtro UCM es una lente de protección óptima para realizar trabajos de soldadura oxiacetilénica, siendo propuesto como filtro de referencia a los organismos competentes para su homologación.
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, Celia
Purpose: 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.