6.12 Summary


The biological path to decreased vision due to diabetic retinopathy and DME begins with chronically elevated blood glucose levels. Over time, poor glycemic control damages the vascular tissue, in particular the endothelial cells and the pericytes (perivascular cells), resulting in vascular dysfunction, inflammation, and hypoxia. Hypoxia, in turn, causes increased VEGF levels in retinal tissue, leading to increased vascular permeability and an accumulation of fluid.

Test Module 6

1. The stimulus for the production of VEGF in the retina is:

2. True or False: There are typically many warning signs indicating the onset of diabetic macular edema?

3. A 1% decrease in HbA1c can do which of the following?

4. Hyperglycemia causes oxidative stress which triggers the activation of which enzyme?

5. An imbalance between oxygen free radicals, or reactive oxygen species (ROS), and the antioxidant defenses of a biologic system defines:

6. A number of the biochemical mechanisms that contribute to the pathogenesis of diabetic retinopathy appear to be associated with

7. Oxidative stress constitutes a unifying mechanism that can be linked to all of the damaging mechanisms in diabetic retinopathy induced by:

8. AGEs are present in normal individuals, but in diabetes

9. The formations of AGEs may cause the following effect in the retina:

10. Metabolization of excess glucose in the polyol pathway leads to multiple intracellular problems in diabetes, except

11. In hyperglycemia-induced oxidative stress, the metabolism of glucose is