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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The slow progression of diabetic retinopathy makes it difficult to assess the effects of intervention therapy. There is thus a need for surrogate markers of visual change in diabetes. Colour vision tests and electroretinography (ERG) may be useful in this regard; yet little is known of their relative performance in the assessment of visual dysfunction in diabetes. The aim of the present study was to compare colour discrimination (100 hue test) and ERG indices (oscillatory potentials (OP) and pattern ERG (PERG)) in the evaluation of aretinopathic IDDM patients. Colour discrimination was abnormal in 10 aretinopathic IDDM patients when compared with nine age matched controls; mean square root 100 hue error scores were 10.38 (SD 2.89) versus 4.77 (1.87) respectively, p < 0.01. OP implicit times of the ERG were also abnormal; for example, for right eye, mean OP1 implicit time for diabetics versus OP1 implicit time for controls was 20.1 (2.0) versus 18.6 (1.4) ms, p = 0.03. Comparison of the two techniques suggested that the 100 hue test was more sensitive and more specific than ERG OP implicit times in the detection of diabetic visual dysfunction in these patients.
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PMID:Comparison of colour discrimination and electroretinography in evaluation of visual pathway dysfunction in aretinopathic IDDM patients. 788 Jul 89

Diabetic retinopathy, a vision-threatening disease, has been regarded as a vascular disorder. However, impaired oscillatory potentials (OPs) in the electroretinogram (ERG) and visual dysfunction are recorded before severe vascular lesions appear. Here, we review the molecular mechanisms underlying the retinal neural degeneration observed in the streptozotocin-(STZ-) induced type 1 diabetes model. The renin-angiotensin system (RAS) and reactive oxygen species (ROS) both cause OP impairment and reduced levels of synaptophysin, a synaptic vesicle protein for neurotransmitter release, most likely through excessive protein degradation by the ubiquitin-proteasome system. ROS also decrease brain-derived neurotrophic factor (BDNF) and inner retinal neuronal cells. The influence of both RAS and ROS on synaptophysin suggests that RAS-ROS crosstalk occurs in the diabetic retina. Therefore, suppressors of RAS or ROS, such as angiotensin II type 1 receptor blockers or the antioxidant lutein, respectively, are potential candidates for neuroprotective and preventive therapies to improve the visual prognosis.
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PMID:Neural degeneration in the retina of the streptozotocin-induced type 1 diabetes model. 2214 84

Dopamine (DA) functions as an essential neuromodulator in the brain and retina such that disruptions in the dopaminergic system are associated with common neurologic disorders such as Parkinson's disease. Although a reduction in DA content has been observed in diabetes, its effects in the development of diabetes-induced neuropathy remains unknown. Because the retina is rich in DA and has a well known diabetes-induced pathology (diabetic retinopathy or DR), this study was designed to examine the role of retinal DA deficiency in early visual defects in DR. Using rodent models of type 1 diabetes mellitus, we investigated whether diabetes caused a reduction in retinal DA content in both rats and mice and determined whether restoring DA levels or activating specific DA receptor pathways could improve visual function (evaluated with optokinetic tracking response) of diabetic mice, potentially via improvement of retinal function (assessed with electroretinography). We found that diabetes significantly reduced DA levels by 4 weeks in rats and by 5 weeks in mice, coincident with the initial detection of visual deficits. Treatment with l-DOPA, a DA precursor, improved overall retinal and visual functions in diabetic mice and acute treatment with DA D1 or D4 receptor agonists improved spatial frequency threshold or contrast sensitivity, respectively. Together, our results indicate that retinal DA deficiency is an underlying mechanism for early, diabetes-induced visual dysfunction and suggest that therapies targeting the retinal dopaminergic system may be beneficial in early-stage DR.
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PMID:Dopamine deficiency contributes to early visual dysfunction in a rodent model of type 1 diabetes. 2443 31