Mirella Gualtieri
University of São Paulo
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Featured researches published by Mirella Gualtieri.
Ophthalmic and Physiological Optics | 2010
Claudia Feitosa-Santana; Galina V. Paramei; Mauro Nishi; Mirella Gualtieri; Marcelo Fernandes Costa; Dora Fix Ventura
Color vision impairment emerges at early stages of diabetes mellitus type 2 (DM2) and may precede diabetic retinopathy or the appearance of vascular alterations in the retina. The aim of the present study was to compare the evaluation of the color vision with two different tests – the Lanthony desaturated D‐15d test (a traditional color arrangement test), and the Cambridge Colour Test (CCT) (a computerized color discrimination test) – in patients diagnosed with DM2 without clinical signs of diabetic retinopathy (DR), and in sex‐ and age‐matched control groups. Both color tests revealed statistically significant differences between the controls and the worst eyes of the DM2 patients. In addition, the degree of color vision impairment diagnosed by both tests correlated with the disease duration. The D‐15d outcomes indicated solely tritan losses. In comparison, CCT outcomes revealed diffuse losses in color discrimination: 13.3% for best eyes and 29% for worst eyes. In addition, elevation of tritan thresholds in the DM2 patients, as detected by the Trivector subtest of the CCT, was found to correlate with the level of glycated hemoglobin. Outcomes of both tests confirm that subclinical losses of color vision are present in DM2 patients at an early stage of the disease, prior to signs of retinopathy. Considering the advantages of the CCT test compared to the D‐15d test, further studies should attempt to verify and/or improve the efficiency of the CCT test.
PLOS ONE | 2012
Thiago L. Costa; Mirella Telles Salgueiro Barboni; Ana Laura de Araújo Moura; Daniela Maria Oliveira Bonci; Mirella Gualtieri; Luiz Carlos L. Silveira; Dora Fix Ventura
The purpose of this study was to evaluate the visual outcome of chronic occupational exposure to a mixture of organic solvents by measuring color discrimination, achromatic contrast sensitivity and visual fields in a group of gas station workers. We tested 25 workers (20 males) and 25 controls with no history of chronic exposure to solvents (10 males). All participants had normal ophthalmologic exams. Subjects had worked in gas stations on an average of 9.6±6.2 years. Color vision was evaluated with the Lanthony D15d and Cambridge Colour Test (CCT). Visual field assessment consisted of white-on-white 24–2 automatic perimetry (Humphrey II-750i). Contrast sensitivity was measured for sinusoidal gratings of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0 and 20.0 cycles per degree (cpd). Results from both groups were compared using the Mann–Whitney U test. The number of errors in the D15d was higher for workers relative to controls (p<0.01). Their CCT color discrimination thresholds were elevated compared to the control group along the protan, deutan and tritan confusion axes (p<0.01), and their ellipse area and ellipticity were higher (p<0.01). Genetic analysis of subjects with very elevated color discrimination thresholds excluded congenital causes for the visual losses. Automated perimetry thresholds showed elevation in the 9°, 15° and 21° of eccentricity (p<0.01) and in MD and PSD indexes (p<0.01). Contrast sensitivity losses were found for all spatial frequencies measured (p<0.01) except for 0.5 cpd. Significant correlation was found between previous working years and deutan axis thresholds (rho = 0.59; p<0.05), indexes of the Lanthony D15d (rho = 0.52; p<0.05), perimetry results in the fovea (rho = −0.51; p<0.05) and at 3, 9 and 15 degrees of eccentricity (rho = −0.46; p<0.05). Extensive and diffuse visual changes were found, suggesting that specific occupational limits should be created.
Experimental Brain Research | 2015
Thiago L. Costa; Mirella Gualtieri; Mirella Telles Salgueiro Barboni; Rafael K. Katayama; Paulo S. Boggio; Dora Fix Ventura
Recent research suggested that transcranial direct current stimulation (tDCS) can affect visual processing and that it can be useful in visual rehabilitation. Nevertheless, there are still few investigations on the subject. tDCS selectivity and the extent of its outcomes on visual perception are still to be assessed. Here, we investigate whether central and peripheral visual fields are equally affected by tDCS. We also tried to reproduce a previous work that has evaluated tDCS effects on the central visual field only (Kraft et al. 207:283–290, 2010). Fifteen healthy subjects participated in this randomized repeated-measure design study and received 1.5-mA anodal, cathodal and sham stimulation in different sessions, while performing 10-2 and 60-4 protocols in an automated perimeter. Anodal tDCS significantly decreased thresholds, but was limited to the most eccentric regions of the visual field measured (60°). This suggests that tDCS might be used for rehabilitation of peripheral visual field losses. We did not replicate the excitatory tDCS effect in the central visual field as previously reported by another group. Instead, we observed a trend toward an inhibitory (yet not statistically significant) effect of anodal tDCS on the central field. This might be explained by methodological differences. These results highlight that although tDCS is a technique with a low focality in the spatial domain, its effects might be highly focal in a functional domain. When taken together with previous findings, this also suggests that tDCS may have a differential effect on different retinotopic areas in the brain.
Investigative Ophthalmology & Visual Science | 2007
Dora Fix Ventura; Mirella Gualtieri; A. G. F. Oliveira; Marcelo Fernandes Costa; Peter A. Quiros; F. Sadun; Anna Maria De Negri; Solange R. Salomão; Adriana Berezovsky; Jerome Sherman; Alfredo A. Sadun; Valerio Carelli
Investigative Ophthalmology & Visual Science | 2005
Dora Fix Ventura; Peter A. Quiros; Valerio Carelli; Solange R. Salomão; Mirella Gualtieri; A. G. F. Oliveira; Marcelo Fernandes Costa; Adriana Berezovsky; F. Sadun; Anna Maria De Negri; Alfredo A. Sadun
Archive | 2003
D.F. Ventura; Luiz Carlos L. Silveira; Anderson R. Rodrigues; J. M. De Souza; Mirella Gualtieri; D. Bonci; Marcelo Fernandes Costa
Investigative Ophthalmology & Visual Science | 2011
Mirella Gualtieri; Marcio L. Bandeira; Russell D. Hamer; Francisco Max Damico; Ana Laura de Araújo Moura; Dora Fix Ventura
Environmental Research | 2008
Mirella Telles Salgueiro Barboni; Marcelo Fernandes Costa; Ana Laura de Araújo Moura; Claudia Feitosa-Santana; Mirella Gualtieri; M. Lago; Marcília de Araújo Medrado‐Faria; Luiz Carlos L. Silveira; Dora Fix Ventura
Archive | 2003
D.F. Ventura; Marcelo Fernandes Costa; Mirella Gualtieri; Mauro Nishi; M. Bernick; D. Bonci; J. M. De Souza
Arquivos Brasileiros De Oftalmologia | 2003
Dora Fix Ventura; Luiz Carlos L. Silveira; Mauro Nishi; Marcelo Fernandes Costa; Mirella Gualtieri; Ruth M. A. dos Santos; Carolina T. Pinto; Ana Laura A. de Moura; Anderson R. Rodrigues; Claudio Sakurada; Maria de Fátima L.C. Sauma; John Manuel de Souza