Suchergebnisse

The Children's Visual Function Questionnaire (CVFQ) is an instrument to measure the impact of visual impairment in children and their families. It can be used as a research tool to verify the effectiveness of treatment, therapy, and different methods for visual stimulation and rehabilitation. The aim of this study is to describe the relationship between General Health, General Vision Health, Personality, Family Impact, and Treatment – subscales of the CVFQ and psychophysical measures of visual acuity (VA) and chromaticity discrimination (CV). This prospective, cross-sectional study was conducted at the Sensory Psychophysiology Laboratory – University of São Paulo in partnership with the Ambulatory of Visual Stimulation in the Sector of Low Vision and Visual Rehabilitation – Federal University of São Paulo. The children who participated in this study were divided into two groups: study group (SG), composed of 11 children with a diagnosis of visual impairment and mean age of 55.36 months ( SD = 16.88), and control group (CG), composed of 8 children with normal vision and mean age of 64.87 months ( SD = 13.22). Both groups underwent the application of CVFQ, were tested for VA using the Teller Acuity Cards (TAC) test, and CV using the Cambridge Colour Test program for children (CCT Kids). The result of applying the CVFQ to groups of children over 3 years, comparing SG and CG, differences were observed in the following subscales: General Vision Health ( F = 10.00, p < .001); Competence ( F = 7.03, p = .030); Personality ( F = 6.48, p = .010); Total Quality of Life ( F = 11.39, p = .010). These differences show a worse score for the SG. In the VA test using TAC, the data collected in groups of children over 3 years, comparing SG and CG, differences were observed in VA RE ( F = 19.25, p < .001); VA LE ( F = 25.99, p < .001); VA BE ( F = 15.45, p < .001). These differences show worse scores for the SG. In the CV using the CCT Kids, the data collected in groups of children over 3 years, comparing SG and CG, no statistically significant differences for protan, tritan, and deutan groups were observed. For the SG, while for children over 3 years, correlations were found for General Vision Health, Competence, Family Impact, and General Quality of Life. We conclude that there are statistically significant differences when comparing the SG with the CG for the visual function of visual acuity and chromaticity discrimination, and we also demonstrated the sensitivity in the use of CVFQ in reflect VA and CV impairments.

Hemispheric asymmetry in processing visual stimuli was assessed in anisometropic and strabismic amblyopia and control subjects. Measurements of contrast sensitivity for low and high spatial frequencies were performed psychophysically and tested under functional magnetic resonance imaging (fMRI) using a stimulus configuration that generates measurements for each temporal and nasal hemifield. The fMRI and the psychophysics results showed a marked hemispheric asymmetry in processing spatial frequencies for normal and anisometropic adults, in which low spatial frequencies were mainly processed in the left visual field – right hemisphere (LVF-RH: 0.3 cycles per degree [cpd]; F = 12.548; p = .002) and the high spatial frequencies were predominating processed in the right visual field – left hemisphere (RVF-LH: 2.0 cpd; F = 4.582; p = .021 and 8.3 cpd; F = 8.561; p = .001). No asymmetry was present in the amblyopic and the fellow eye of the strabismic amblyopia subjects. We conclude that the developmental organization of visual cortex in strabismic amblyopia is impaired differently from what happens in the anisometropic amblyopia and support the impairment of high-level visual-related functions observed in strabismic children.

We validated the recently developed functional vision evaluation for children (FVEC) battery, which quantitatively measures major eye and visual functions for rehabilitation. The protocol for this test comprises 12 items involving unique abilities of the functional vision evaluated for three subsequent periods. The validation procedure includes an analysis of the difficulty of the examiner's performance, the reliability and symmetry evaluation of the battery items, and the prediction of the children in the low vision category on a 0 to 100 ranking scale of visual behaviors. Factor analysis evaluates the contribution of the items to functions of the ventral and dorsal visual streams. Consistency was similar between the three examiners and the reliability intra-subjects was also significantly high for examiner 1 (α = 0.86), examiner 2 (α = 0.85), and examiner 3 (α = 0.87). A factor analysis confirms that we arranged our data in two major factors expressing ventral and dorsal visual functions. The FVEC battery was validated showing high robustness, and internal consistency. The final scoring allows a qualitative and quantitative evaluation regarding the performances of the visual ventral and dorsal functions. Improvements in visual rehabilitation protocols based on FVEC battery are discussed.