Person: Pérez Carrasco, María Jesús
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First Name
María Jesús
Last Name
Pérez Carrasco
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Optometría y Visión
Area
Optica
Identifiers
11 results
Search Results
Now showing 1 - 10 of 11
Item Effect of a yellow filter on mesopic contrast perception and differential light sensitivity in the visual field.(Ophthalmic Research, 2003) Pérez Carrasco, María Jesús; Puell Marín, María Cinta; Sánchez Ramos, Celia; Langa Moraga, AntonioPurpose: Previous studies on the effects of yellow filters in the visual performance have been carried out, presenting discrepancies among the different investigations. Our study reports the influence of the yellow filter without residual reflections on contrast perception and differential light sensitivity (DLS) under mesopic conditions. Methods: Contrast sensitivity, low contrast visual acuity and luminance thresholds in the central visual field (30 degrees ) were measured in a group of 38 adult subjects with and without a coated yellow lens (482-nm cut-off) under mesopic conditions. Results: The contrast sensitivity mean was significantly better with the filter at low- and middle-range spatial frequencies (1.5 cycles/degree p = 0.002 and 6 cycles/degree p = 0.02). At 5% contrast, the mesopic low contrast visual acuity improved significantly (p = 0.004) when interposing the yellow filter. The increase in DLS was statistically significant [e.g. all visual fields p = 0.0003 and macular visual field (9.5 degrees ) p = 0.00001] through the yellow filter on the different established areas of the visual field (30 degrees ). Conclusions: The yellow filter without residual reflections had a positive influence on the brightness and contrast perception of healthy subjects, for which its use would be beneficial under mesopic conditions.Item Nuevo instrumento para medir la sensibilidad al contraste sin y con deslumbramiento(Archivos de la Sociedad Española de Oftalmología, 2003) Sánchez Ramos, Celia; Puell Marín, María Cinta; Pérez Carrasco, María Jesús; Langa Moraga, Antonio; Benítez Del Castillo Sánchez, José ManuelOBJETIVO/MÉTODO: valorar la sensibilidad al contraste fotópica, sin y con deslumbramiento con un nuevo instrumento. Se estudiaron 78 ojos derechos de 49 adultos jóvenes y de 29 adultos entre 35 y 55 años. La sensibilidad al contraste se midió con el Contrast Glarester CGT-1000 mediante una estrategia automatizada de reconocimiento para seis frecuencias espaciales. RESULTADOS/CONCLUSIONES: Los valores de sensibilidad al contraste fueron semejantes a los obtenidos con otros test clínicos. El aumento de la edad disminuyó significativamente la sensibilidad al contraste sin y con deslumbramiento. Sin embargo, el deslumbramiento no modificó la sensibilidad al contraste fotópica.Item Efectividad de los filtros polarizados frente a los coloreados en la Sensibilidad al Contraste bajo condiciones de deslumbramiento central por reflexión.(Ver y Oír, 2008) Sillero, Manuel; Moral Martinez, Inmaculada; Langa Moraga, Antonio; Pérez Carrasco, María Jesús; Sánchez Ramos, CeliaLa efectividad de los filtros polarizados frente al deslumbramiento central por reflexión ha sido demostrada sólo mediante test empíricos de laboratorio, pero no desde el punto de vista fisiológico. En este trabajo se midieron, en 96 sujetos adltos de un amplio rango de edad, los efectos del deslumbramiento central por reflexión y en ausencia de él, con filtros polarizados, filtros coloreados y sin filtros, utilizando un protocolo original próximo a las condiciones de la vida real. La aproximación ecológica confirma que los filtros polarizados son significativamente más efectivos que los coloreados frente al deslumbramiento central por reflexión.Item Effect of Mesopic/Scotopic Luminance on Pupil Diameter and Anisocoria in Drivers Over 65 Years of Age(2005) Pérez Carrasco, María Jesús; Sánchez Ramos, Celia; Moral Martínez, M.I.; Puell Marín, María Cinta; Langa Moraga, AntonioPurpose: To evaluate the changes produced in pupil diameter and anisocoria in mesopic and scotopic conditions in subjects over the age of 65 years. Methods: A prospective evaluation was performed of pupil diameter in 45 motor car drivers aged 65 to 80 years (69±6 years). Measurements were made using an infrared, binocular pupillometer P2000 (Procyon Instruments Ltd) at 3 luminance levels: 0.04 lux (scotopic), 0.4 lux (low mesopic) and 4 lux (high mesopic). For each measurement, 10 photographs of both eyes are automatically taken by the instrument. Results: In scotopic conditions, mean pupil sizes were RE 5.37±1.1 mm, LE 5.29±1 mm. When the luminance level was increased to 0.4 lux (low mesopic conditions) mioses of 18% and 17%, respectively for the right and left eyes, were observed, resulting in pupil diameters of RE 4.55±0.83 mm, LE 4.51±0.78 mm. In high mesopic conditions (4 lux), pupil diameters were RE 3.47±0.60 mm, LE 3.41±0.89 mm, corresponding to mioses from the previous luminance level of 28% and 29%, respectively. The diferences in pupil diameter among the three luminance levels were significant. No diferences attributable to the luminance level were detected between each eye. The degrees of anisocoria observed were 5.77%, 5.78% and 5.77% in scotopic, low and high mesopic conditions, respectively. No significant diferences in scotopic/mesopic pupil sizes were revealed when the population was divided into three (15–year) age groups, or according to sex. Conclusions: At scotopic and mesopic luminance levels, drivers over 65 years show significant diferences in pupil diameter but no changes in anisocoria.Item Mesopic contrast sensitivity and glare disability in drivers.(2003) Sánchez Ramos, Celia; Puell Marín, María Cinta; Pérez Carrasco, María Jesús; Langa Moraga, Antonio; Benítez Del Castillo Sánchez, José ManuelVisual Acuity is a poor predictor of driving ability and it is likely to be a poor predictor of many aspects of real-world vision, because the real world is not composed purely of fine objects with sharp edges at high contrast. Although not all objects are at contrst treshold either, it has been shown that a loss of contrast sensitivity (CS) is roughly equivalent to a loss of image contrast in the normal eye (OWSLEY, 1994). The extent of contrast loss required before real-world performance is reduced depends on the real-world task being performed. Somo tasks, such as optimal speed reading and mobility orientation in a well-llit room, tolerate large reductions in contrast (Elliot, 1996; Leffe, 1993; Pelli, 1986). These tasks would probably only be affected in patients with a severe loss of contrast sensitivity. However, other tasks such as speed reading newspaper-size print and face recognition are moderately affected by contrast reduction (Elliot, 1996). Further, mobility orientation under dim illumination has been shown to be seriously affected by reduced contrast. Thus, under low-iluminance conditions and when a subject is working near his or her acuity limit, tolerance to contrast loss is reduced (Legge, 1993)Item Age effects on mesopic and scotopic anisocoria determined in vehicle drivers.(2005) Sánchez Ramos, Celia; Puell Marín, María Cinta; Pérez Carrasco, María Jesús; Langa Moraga, Antonio; Moral Martínez, M.I.The diameter of the pupil affects a person´s vision in a complex manner. As the pupil dilates, it allows more light to enter the eye and stimulate the retina, reducing blur caused by diffraction to a minimum. A narrow pupil, on the other hand, reduces the negative effects of these aberrations on the crystaline lens. In general, a pupil diameter of 3 to 6 mm increases clarity of vision. Owing to the adaptation process, humans can tolerate a difference in luminance conditions from 1 to 10000000 cd/m2. The spectrum of visual sensitivity is so broad that in a graph, the intensity of light has to be plotted on a logarithmic scale.Item Straylight in older drivers.(2009) Sánchez Ramos, Celia; Colilla, E.A.; Gómer Tortuero, E.; Langa Moraga, Antonio; Pérez Carrasco, María JesúsThe measures of the dazzle and of the dispersion of the light intraocular are particularly important for the drivers and affected subjects of cataracts. The technology of measure of the strylight values the dispersion of the light for psycophysical methods allos to know the state of the visual function of olders drivers. The aim is to evaluate de validity of the measure of the dispersion of the light intraocular as enough indicator to determine the visual capacity of the drivers´s in conditions mesópica.Item Características funcionales y ergonómicas de las lentes ocupacionales.(2005) Sánchez Ramos, Celia; Moral Martínez, M.I.; Alonso Fernández, José; Puell Marín, María Cinta; Langa Moraga, Antonio; Pérez Carrasco, María JesúsEl propósito de este trabajo ha sido evaluar tanto objetiva como subjetivamente las características ergonómicas y funcionales de las lentes ocupacionales, comparándolas con las lentes monofocales convencionales. Esta evaluación se ha realizado con pruebas psicofísicas como sensibilidad al contraste, agudeza visual de contraste variable, y perimetría FDT, además de con un cuestionario subjetivo. La muestra ha estado compuesta por 30 pacientes con edades comprendidas entre 40 y 58 años. Las conclusiones indican que tanto objetiva como subjetivamente se obtienen diferencias por el uso de las lentes ocupacionales.Item Increase of the spatial resolution and of the contrast sensitivity for myosis induced in usual drivers demonstrates experimentally.(2009) Sánchez Ramos, Celia; Langa Moraga, Antonio; Gómez Tortuero, E.; Pérez Carrasco, María Jesús; Colilla, E.Human visual system is able to adapt itself to get better visual perception in a very extense lighting range, since light of the moon until brilliant sunlight, so from scotopic until photopic lighting (Walkey and Barbur, 2006). Changes in pupil size produced in response to changes in light intensity optimise the amount of light received by the retina, maximizing visual perception. This is produced along 10 log units, thanks to the human eye adaptation by biochemical and nervous mechanisms. In the light/darkness process of adaptation mechanical activity, due to pupil size variations (Myosis/mydriasis), contributes 1 logarithmic unit and is the most rapid of all contributions to the response. Between both lighting limits (photopic and scotopic), mesopic range is establised. This lighting (mesopic) is found in a natural way when night falls or at dawn, time in which driving becomes a harder task, thus its study has such an enormous interest due to its influence of driving. Mesopic vision describes the period of trnsition from rods (Scotopic) until cones (photopic) vision, in which both photoreceptors contributes to the visual response. Although it hasn´t been precisely establised by the CIE (Commission Internationale de l´Eclairage), mesopic range covers roughly 4 log units (Wyszecky y Stiles 1982; Walkey et al. 2006), which means lighting levels frecuently used in occupational ambient. In mesopic lighting condition several changes are produced in visual function. Pupil size variations distort the optic of the eye, degrading the quality of the retinal image (aberrations and light dispersion). On the other hand, the extensive spatial summation of the rods signal increases the light sensitivity but also causes a significant lost of contras sensitivity, the visual acuity of low contrast and the spatial resolution (Walkey y Barbur, 2006).Item Efecto del hialuronato sódico (0.15%) en la sensibilidad al contraste en ojo seco con déficit hormonal.(2005) Sánchez Ramos, Celia; Llorens Casado, María Belén; Moral Martínez, I.; Puell Marín, María Cinta; Gonzalvo, M.T.; Pérez Carrasco, María Jesús; Langa Moraga, Antonio; Benítez Del Castillo Sánchez, José Manuel; Sáenz Francés, F.Los cambios de la actividad metabólica inducidos por las variaciones hormonales producen síntomas asociados, como la patología del "ojo seco". El tratamiento más frecuente para la sequedad ocular es la aplicación de lágrimas artificiales. El hialuronato sódico es uno de los fármacos que reconstruye la película lagrimal. No obstante, se desconoce su efecto en la percepción visual, especialmente en los que respeta a su posible repercusión en la sensibilidad al contraste y más concretamente en pacientes postmenopáusicas que presentan patología de "ojo seco". Por ello se plantea este estudio, cuyo objetivo es valorar la eficacia del hialuronato sódico en mujeres potmenopáusicas que sufren esta patología, mediante la determinación de las variaciones en su función de la sensibilidad al contraste.