Full text
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| Author(s): |
Leonardo Aparecido Silva
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Psicologia (IP/SBD) |
| Defense date: | 2019-11-28 |
| Examining board members: |
Dora Selma Fix Ventura;
Francisco Max Damico;
Givago da Silva Souza
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| Advisor: | Dora Selma Fix Ventura |
| Abstract | |
INTRODUCTION: Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are neuromuscular disorders linked to mutations in the Dmd gene located in the short arm of the X chromosome. The Dmd gene, located in the Xp21 region, is responsible for the production of the protein dystrophin. This protein is one of the proteins that form the glycoprotein complex necessary for the integrity of the muscle fiber and its dysfunction causes DMD and BMD. In addition, dystrophin is required for retinal physiology and therefore for processing visual information for both color discrimination and contrast sensitivity. OBJECTIVE: To analyze the impact of different types of the Dmd gene alteration on the color discrimination and contrast sensitivity of patients with DMD and BMD. METHODOLOGY: The study comprised a visual evaluation of three groups of subjects: i) patients with DMD (n = 87); BMD patients (n = 10) and healthy volunteers (n = 41) using two new tablet-adapted psychophysical tests - Tablet Color Vision Test (CVT) for chromatic discrimination and Tablet Contrast Sensitivity Test (CST) for luminance spatial contrast sensitivity. The tablet CVT uses mosaics of small points in which the target (stimulus) and the background show only chromatic differences without borders and with a variation of luminance for the protan, deutan and tritan axes, while the CST tablet uses static achromatic stimuli (black and white) at spatial frequencies: 0.8; 1.4; 2.0; 4.0; 10.0 and 16.0 cycles per degree. RESULTS: Significant statistical differences (p<0,05) were found in the color discrimination limit for the protan, deutan and tritan axes between the control group and the DMD subgroups according and also in the BMD group using the Tablet CVT. There were also statistically significant differences (p <0.05) in the sensitivity to luminance contrast of participants with DMD compared to controls in the Tablet CST at spatial frequencies 0.8 cpg, 2.0 cpg and 4.0. In the BMD group, the sensitivity to spatial contrast did not present statistically significant differences. CONCLUSIONS: Impaired chromatic discrimination was found in participants with DMD and BMD on the protan, deutan, tritan axes, independently of the locus of genetic alteration and the same was found for contrast sensitivity in participants with DMD, but not in the BMD group. The results contribute to a better detailed of human vision regarding the different types of DMD gene mutation, as affected visual mechanisms seem to be related to a wide variety of dystrophin proteins (AU) | |
| FAPESP's process: | 17/16948-4 - Impact of different types of modification of the gene for dystrophin in the vision of patients with muscular dystrophy |
| Grantee: | Leonardo Aparecido Silva |
| Support Opportunities: | Scholarships in Brazil - Master |