Color vision, contrast sensitivity and multifocal electroretinogram in subjects with Diabetes Mellitus type 1

Author(s)

Valéria Duarte Garcia

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Psicologia (IP/SBD)
• Defense date: 2012-07-18

Examining board members

Dora Selma Fix Ventura; Francisco Max Damico; Mirella Gualtieri

• Advisor: Dora Selma Fix Ventura

Abstract

Diabetes Mellitus (DM) is a chronic disease that compromises different aspects of human health and at different times during its progression.. One of the most prevalent complications associated with DM is diabetic retinopathy (DR), which produces losses in different visual functions and can result in blindness. The visual losses can be detected prior to the development of DR and can lead to improvements in the control, prevention and treatment of DR. The present work investigates the color discrimination, contrast sensitivity and the electrophysiological responses patterns of the multifocal electroretinogram (mfERG) using the latest generation of psychophysical and electrophysiological tests in twenty patients (age=28.20; SD=7.12) with Diabetes Mellitus type 1 without DR compared to twenty subjects (age=28.29; SD=5.03) without diabetes and ocular disease. The color discrimination was performed through CCT (Cambridge Colour Test) and contrast sensitivity by Metropsis software (Cambridge Research System, Ltd) using vertical sine wave gratings in seven spatial frequencies (0.2; 0.5; 1; 2; 5; 10; 20 cpd). The retinal electrophysiological function was evaluated with mfERG. The data comparison among groups was performed with ANOVA test. In the Trivector protocol of CCT the diabetic patients showed differences in all axes protan (p = 0,026), deutan (p = 0,012) and tritan (p = 0,001); in the elipses protocol there was a diffuse loss in the patients discrimination (p = 0,002). The contrast sensitivity was reduced in the diabetic group, in particular to the spatial frequencies of 0.2 (p = 0,037) and 5 (p = 0,004)cpd. The results of mfERG from the DM group showed an implicit time bigger in N1 0º (p = 0,03) and N2 5º (p = 0,04) (0º) compared to the control group and a reduced amplitude of N2 20º (p = 0,04) e 25º (p = 0,02). In conclusion, the patients with diabetes type 1 present with behavioral and electrophysiological visual losses, however, they do not show retinopathy. These findings confirm previous results shown in the literature from other tests (AU)

• FAPESP's process: 09/12878-5 - Color vision and contrast sensitivity in subjects with type 1 Diabetes mellitus.
• Grantee: Valéria Duarte Garcia
• Support Opportunities: Scholarships in Brazil - Master