Purchase this article with an account.
Valéria Garcia, Mirella Gualtieri, Mirella Barboni, Daniela Bonci, Thiago Costa, Balázs Nagy, Sérgio Rodrigues, Ana Moura, Francisco Max Damico, Dora Ventura; Psychophysical and electrophysiological evaluation of visual function in type 1 diabetics. Invest. Ophthalmol. Vis. Sci. 2013;54(15):3026.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Diabetes mellitus (DM) is a chronic disease that impairs different aspects of health at different times during its progression. One of the most prevalent complications associated with DM is diabetic retinopathy (DR), which causes losses in visual functions and can ultimately result in blindness. Visual loss can be detected prior to the development of DR, potentially leading to improvement in the blood sugar control, prevention, and treatment of DR. The present work investigated color discrimination, contrast sensitivity and the multifocal electroretinogram (mfERG) of type 1 DM patients without DR.
Twenty patients with type 1 DM without DR (mean age = 28 ± 7 years old) were compared to 20 control subjects without diabetes or ocular diseases (mean age = 28 ± 5). Color discrimination was evaluated with the Cambridge Colour Test (CCT) and contrast sensitivity with the Metropsis software (Cambridge Research System, Ltd) using vertical sine wave gratings at seven spatial frequencies (0.2; 0.5; 1; 2; 5; 10; 20 cpd). The Visual Evoked Response Imagining System (VERIS) was used to record the mfERGs . Groups were compared using ANOVA.
Type 1 diabetic patients presented significantly elevated values for all CCT parameters compared to control subjects. Protan, deutan and tritan thresholds in u’v’ units were respectively 51.95 ± 23.81 (F1,40 = 5.384, p = 0.026); 53.45 ± 25.66 (F1,40 = 6.90, p = 0,012) and 93,90 ± 41,94 (F1,40 = 14.30, p = 0.001); elipse area was 1672 ± 1102 (F1,40 = 11.665, p = 0.002). Contrast sensitivity was reduced in the diabetics at 0. 2 cpd (F1,40 = 4.67, p = 0.037) and 5 cpd (F1,40 = 6.08, p = 0.004). mfERGs of DM patients showed increased implicit time for N1 at 0° (F1,40 = 5.18, p = 0.03) and N2 at 5°(F1,40 = 4.15, p = 0.04) eccentricities. In addition, there was reduced amplitude of N2 at the 20° (F1,40 = 4.40, p = 0.04) and 25° (F1,40 = 5.42, p = 0.02) eccentricities.
Non retinopathic type 1 diabetes mellitus patients present significant visual loss detectable by psychophysical and electrophysiological tests. Retinal hypoxia caused by chronic hyperglycemia has been identified as the main reason for reduced visual functions detected in the early DM, including color vision loss and contrast sensitivity. These findings suggest that psychophysical and electrophysiological tests should be routinely performed in diabetic patients
This PDF is available to Subscribers Only