Lucha epidemiológica contra pandemia COVID-19: Impacto de las medidas sociales en el SVI / Epidemiological fight against the COVID-19 pandemic: Impact of social measures on IVS

La lucha epidemiológica contra la pandemia COVID-19 ha incluido medidas sociales como el confinamiento y el cierre de actividades laborales y académicas. A consecuencia, tareas que se llevaban a cabo en el contexto presencial debieron ser ejecutadas desde los hogares, adoptando estrategias como el teletrabajo y la educación virtual, haciendo necesario el uso de herramientas como ordenadores y laptops. De allí que las personas han incrementado la exposición a las pantallas de dispositivos electrónicos, como son computadoras y laptops, trayendo como consecuencia afectaciones en la salud visual de las personas tales como el síndrome visual informático (SVI). Se realizó un estudio transversal con el objetivo de determinar la afectación por SVI en la población peruana y su relación con la exposición prolongada a DEV, generada a raíz de las medidas sociales de enfrentamiento a la pandemia de COVID-19. El tiempo promedio en que los sujetos de nuestro estudio usaron DEV dentro de los hogares se acrecentó un 120%, es decir 4,26±2,36 horas diarias adicionales al comparar con el año anterior a la pandemia COVID-19. La adopción masiva de actividades como el teletrabajo y la educación virtual podrían explicar el hecho que los grupos de empleados/patronos y estudiantes fueron los mayores usuarios de DEV, con 10,41 y 9,32 horas diarias. De acuerdo a los hallazgos obtenidos, es estadísticamente válido afirmar que las medidas sociales para enfrentar la pandemia COVID-19 indujeron al aumento en la prevalencia de SVI en los pobladores peruanos (p<0,001). En la actual investigación, la proporción de individuos que manifestaron SVI pasó de 38 a 64%, antes y durante la aplicación de las medidas, respectivamente(AU)

The epidemiological fight against the COVID-19 pandemic has included social measures such as confinement and the closure of work and academic activities. As a consequence, tasks that were carried out in the face-to-face context had to be carried out from homes, adopting strategies such as teleworking and virtual education, requiring the use of tools such as computers and laptops. Hence, people have increased exposure to the screens of electronic devices, such as computers and laptops, resulting in effects on people's visual health such as computer vision syndrome (SVI). A cross-sectional study was carried out in order to determine the affectation by SVI in the Peruvian population and its relationship with prolonged exposure to DEV, generated as a result of social measures to cope with the COVID-19 pandemic. The average time in which the subjects in our study used DEV within homes increased by 120%, that is, 4.26 ± 2.36 additional daily hours when compared to the year before the COVID-19 pandemic. The massive adoption of activities such as teleworking and virtual education could explain the fact that groups of employees / employers and students were the largest users of DEV, with 10.41 and 9.32 hours per day. According to the findings obtained, it is statistically valid to affirm that the social measures to face the COVID-19 pandemic induced an increase in the prevalence of SVI in the Peruvian population (p <0.001). In the current investigation, the proportion of individuals who manifested SVI went from 38 to 64%, before and during the application of the measures, respectively(AU)

Effect of disparity on the perception of motion-defined contours

We present three experiments that explored the effect of binocular disparity on the perception of contours defined by motion in a Spatiotemporal Boundary Formation. Depending on the disparity, the stimulus is perceived as an object that moves behind a holed surface (occluded configuration) or as a luminous transparency that moves over a surface that contains dots (occluding configuration). In all of the experiments, we used a Vernier task to assess the strength of contour perception. In the first experiment, we measured acuity as a function of disparity for a range of speeds and dot densities. The results showed that, despite the difference in the percepts, acuity was similar in both situations, replicating the dependence on speed and dot density demonstrated in previous studies. In the second experiment, the results showed that the dynamics of contour integration were identical for both occluded and occluding configurations. In the third experiment, we tested whether the mechanism of contour integration works independently from the interpretation of the scene. In this experiment, we inverted the disparity during stimulus presentation so that the stimulus switched between occluded and occluding configurations. The results showed that the switch of the depth order increased the threshold to the value obtained with a shorter presentation time. This might be produced by a resetting of the integration process driven by the change of depth order. The results are discussed within a conceptual model that places the process of contour integration in the context of the perception of objects in a Spatiotemporal Boundary Formation...

Reaching for virtual objects: binocular disparity, retinal motion and the control of prehension

To reach for and grasp an object, its distance, shape and size must be known. In principle, the combination of disparity and motion information could be used to provide this information as the perception of object shape from disparity is biased and the perception of object size from motion is indeterminate. Here we investigate whether the visual system can take advantage of the simultaneous presence of both cues of both cues in the control of reaching and grasping. For both real and virtual objects, peak grip aperture scaled with object size and peak wrist velocity scaled with object distance. Kinematic indices, which reflect distance reached and perceived size, showed clear and systematic biases may be interpreted as arising from the biases in the use of binocular disparity, and the indeterminacy of the information provided by motion. Combining disparity and motion information improved estimates of the width, but not the depth or distance of objects. Overall, these results suggest that accurate metric depth information for the control of prehension is not available from binocular or motion cues, either in isolation or in combination.

Enfermedad de Schilder: a propósito de un caso / Schilder disease: apropos of a case

La ahora denominada Leucodistrofia Adrenocortical tipo Schilder, representa una de las formas más graves de demencia asociada o pérdida visual y auditiva en la edad escolar. Presentamos un caso clínico y radiológicamente característico con el objeto de llamar la atención hacia su existencia y hacia la esperanza de poder ahora realizar diagnóstico pre-natal.

Pulsoterapia com corticóide em fribrose sub-retiniana progressiva / Steroid pulsetherapy in progressive subretinal fibrosis

Uma criança de 10 anos, do sexo masculino, apresentou um caso raro de fibrose sub-retiniana progressiva.Inicialmente apenas o olho direito foi afetado.Sem tratamento, este processo evolui para formaçäo de uma extensa zona de fibrose sub-retiniana na área macular, com severo comprometimento visual.Após um ano e cinco meses apareceram lesöes coroidianas multifocais com deslocamento seroso macular no olho esquerdo, tendo sido precocemente tratadas com corticoesteróides.Houve resoluçäo rápida das lesöes, sem cicatrizaçäo sub-retiniana e o paciente manteve acuidade visual normal neste olho.