Streptozotocin-Induced Diabetic Retinopathy (STZ-DR)

Streptozotocin (STZ) is a small molecule that causes depletion of the pancreatic islet cells following systemic administration to rodents.  The islet cell death causes a loss of insulin production and subsequent dysregulation of blood glucose levels leading to hyperglycemia within days.  This model has been used to study inflammation, vascular pathology, and signaling pathways involved in the pathogenesis of Diabetic Retinopathy and Diabetic Macular Edema. At 8 weeks following induction of Diabetes with STZ, there is a significant and progressive loss of visual acuity and contrast sensitivity.

As retinopathy is a major complication of diabetes in humans, these animals are very useful for the testing of anti-inflammatory and anti-angiogenic compounds to reduce vascular leakage and the associated symptoms of retinopathy. Since the primary endpoints accepted by regulatory agencies for human clinical trials are focused on quantitative measurements of visual acuity and contrast sensitivity, this is an excellent model for testing the activity of therapeutic agents to prevent diabetic vision loss. Our group was the first to demonstrate that BN rats develop more severe retinopathy than SD rats, and present a more ideal model for drug screening.

Adult BN rats (8-12 weeks of age) will be given a single intraperitoneal injection of fresh made STZ (50 mg/kg of body weight in 10 mmol/L of citrate buffer, pH 4.5). Serum glucose levels will be examined 2 days after the STZ injection and weekly thereafter. Only the animals with blood glucose levels higher than 350 mg/dl will be used as diabetic rats.


Contrast Sensitivity


Preclinical Ophthalmic Contract Research