1
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Alteraciones de sensibilidad al contraste y estereopsis en trabajadores expuestos a hidrocarburos aromáticos Translated title: Alterations of sensitivity to contrast and stereopsis in workers exposed to aromatic hydrocarbons

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          RESUMEN Objetivos: Los hidrocarburos aromáticos son compuestos que pueden afectar el Sistema Nervioso Central (SNC), provocar neurotoxicidad y asociarse con alteraciones de la función visual. Objetivo general: Establecer la frecuencia de alteraciones en sensibilidad al contraste (SC) y estereopsis, en un grupo de trabajadores expuestos y un grupo no expuestos a hidrocarburos aromáticos. Materiales y métodos: estudio analítico de corte transversal. Muestra: grupo control 20 sujetos, edad media 25 años; grupo expuesto 20 sujetos, edad media 33,4 años. Se realizó valoración optométrica, se evaluaron las vías visuales bajas a través de una prueba de SC con el test FACT (Functional Acuity Contrast Test) y las vías visuales intermedias por la estereopsis con el test Frisby. Resultados: Existe diferencia clínica y estadísticamente significativa para los valores de las frecuencias espaciales de 3.0 cpd, 6.0 cpd y 12.0 cpd, del grupo control comparado con el grupo expuesto, al igual que en la estereopsis fina.

          Translated abstract

          ABSTRACT Objectives: Aromatic hydrocarbons are compounds that can affect the Central Nervous System (CNS), cause neurotoxicity and be associated with alterations in visual function. Course objective: To establish the frequency of alterations in contrast sensitivity (SC) and stereopsis, in a group of exposed workers and a group not exposed to aromatic hydrocarbons. Materials and methods: cross-sectional analytical study. Sample: control group 20 subjects, average age 25; exposed group 20 subjects, mid age 33.4. An optometric assessment was performed; the low visual pathways were evaluated through an SC test with the FACT test (Functional Acuity Contrast Test) and the intermediate visual pathways by stereopsis with the Frisby test. Results: There is a clinically and statistically significant difference for the values of the spatial frequencies of 3.0 cpd, 6.0 cpd and 12.0 cpd, of the control group compared to the exposed group, as in the fine stereopsis.

          Related collections

          Most cited references32

          • Record: found
          • Abstract: found
          • Article: not found

          The contrast sensitivity of retinal ganglion cells of the cat.

          1. Spatial summation within cat retinal receptive fields was studied by recording from optic-tract fibres the responses of ganglion cells to grating patterns whose luminance perpendicular to the bars varied sinusoidally about the mean level. 2. Summation over the receptive fields of some cells (X-cells) was found to be approximately linear, while for other cells (Y-cells) summation was very non-linear. 3. The mean discharge frequency of Y-cells (unlike that of X-cells) was greatly increased when grating patterns drifted across their receptive fields. 4. In twenty-one X-cells the relation between the contrast and spatial frequency of drifting sinusoidal gratings which evoked the same small response was measured. In every case it was found that the reciprocal of this relation, the contrast sensitivity function, could be satisfactorily described by the difference of two Gaussian functions. 5. This finding supports the hypothesis that the sensitivities of the antagonistic centre and surround summating regions of ganglion cell receptive fields fall off as Gaussian functions of the distance from the field centre. 6. The way in which the sensitivity of an X-cell for a contrast-edge pattern varied with the distance of the edge from the receptive field centre was determined and found to be consistent with the cell's measured contrast sensitivity function. 7. Reducing the retinal illumination produced changes in the contrast sensitivity function of an X-cell which suggested that the diameters of the summating regions of the receptive field increased while the surround region became relatively ineffective.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Receptive field structure in the primate retina.

            Barry Lee (1996)
            This review summarizes recent work relevant to receptive field structure of cells of the parvocellular (PC) and (MC) magnocellular pathways in the primate. In the PC-pathway, recent data suggest that different color- and cone-opponent ganglion cells make up specific anatomical classes with specific cone connectivities and bipolar cell input. For example, blue-on ganglion cells have been identified anatomically as the small bistratified ganglion cell class. For the midget ganglion cells, which appear to be red-green opponent, there seems to be only one mosaic for red and green on-center and one for red and green off-center cells. This mixture of cell type within a retinal cell mosaic is unusual, as is the fact that dendritic trees of neighboring midget cells do not overlap. Physiologically, all PC-cells lack a contrast gain control mechanism and show a high degree of spatial and temporal linearity of their responses. In the magnocellular pathway, on- and off-center cells, corresponding to parasol cells with dendritic trees ramifying in the inner and outer sublaminae of the inner plexiform layer, show properties familiar from studies of cat ganglion cells, e.g. a contrast gain control is present. However, a chromatic input to the receptive field surround gives their responses an additional order of complexity.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Effects of moderate dose alcohol on visual contrast sensitivity for stationary and moving targets.

              Contrast sensitivity involves distinguishing threshold luminance differences and is usually assessed using static sine-wave gratings over a range of different spatial frequencies. The purpose of this study was to determine the effects of various levels of acute alcohol intoxication on contrast sensitivity to stationary and moving sine-wave gratings. Moving gratings required the subjects to make pursuit eye movements. A secondary goal was to investigate whether any alcohol-related effects were associated with any measures of intoxication.
                Bookmark

                Author and article information

                Journal
                medtra
                Revista de la Asociación Española de Especialistas en Medicina del Trabajo
                Rev Asoc Esp Espec Med Trab
                Asociación Española de Especialistas en Medicina del Trabajo (Madrid, Madrid, Spain )
                1132-6255
                2019
                : 28
                : 4
                : 244-253
                Affiliations
                [1] orgnameUniversidad de La Salle Colombia
                [2] orgnameUniversidad de La Salle Colombia
                Article
                S1132-62552019000400003 S1132-6255(19)02800400003
                8da265e8-2322-4215-bd10-40bc2152ccc1

                This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

                History
                : 18 December 2019
                : 05 August 2019
                Page count
                Figures: 0, Tables: 0, Equations: 0, References: 47, Pages: 10
                Product

                SciELO Spain

                Categories
                Textos Originales

                Sensibilidad de contraste,estereopsis,sustancias tóxicas,hidrocarburos aromáticos,exposición laboral,Contrast sensitivity,stereopsis,toxic substances,aromatic hydrocarbons,occupational exposure

                Comments

                Comment on this article